Abstract:
A drilling fluid pumping system including a pump apparatus with a pumping chamber having an inlet valve and an outlet valve and a dampener system in fluid communication with the pumping chamber for damping the flow of fluid, e.g. drilling fluid, This abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure and is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims, 37 C. F. R. 1.72(b).

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This is a 371 of PCT/US09/59612, filed Oct. 6, 2009, which was a continuation-in-part of U.S. patent application Ser. No. 12/288,167, filed Oct. 16, 2008. 
    
    
     BACKGROUND OF THE INVENTION 
     This present invention is directed to drilling wellbores in the earth, to systems for pumping drilling fluid (“mud”) for such operations, to mud pumping system modules with surge suppressing dampeners, and to methods of their use. 
     DESCRIPTION OF THE RELATED 
     Known references disclose a wide variety of drilling systems, apparatuses, and methods including, but not limited to, the disclosures in U.S. Pat. Nos. 6,944,547; 6,918,453; 6,802,378; 6,050,348; 5,465,799; 4,995,465; 4,854,397; and 3,658,138, all incorporated fully herein for all purposes. Prior references disclose a wide variety of drilling fluid pumps (“mud pumps”) used in drilling operations and pump systems, for example, and not by way of limitation, those pumps and systems disclosed in U.S. Pat. Nos. 6,257,354; 4,295,366; 4,527,959; 5,616,009; 4,242,057; 4,676,724; 5,823,093; 5,960,700; 5,059,101; 5,253,987; in U.S. application Ser. No. 10/833,921 filed Apr. 28, 2004 (all said U.S. references incorporated fully herein for all purposes). Known references disclose a variety of dampeners, accumulators, and surge suppressors; including, but not limited to, those disclosed in U.S. Pat. Nos. 4,299,253; 4,195,668; 2,757,689; 2,804,884; 3,674,053; 3,169,551; 3,674,053; 3,162,213; 2,380,866; 2,378,467; 2,397,248; 2,397,796; and 2,773,455—all incorporated fully herein for all purposes. 
     A drill bit carried at an end of a drillstring is rotated to form wellbores in the earth. Certain drillstrings include tubulars which may be drill pipe made of jointed sections or a continuous coiled tubing and a drilling assembly that has a drill bit at its bottom end. The drilling assembly is attached to the bottom end of the tubing or drillstring. In certain systems, to drill a wellbore, the drill bit is rotated (e.g., by a top drive, a power swivel, a rotary table system, or by a downhole mud motor carried by the drilling assembly). Drilling fluid, also referred to as “mud,” is pumped through the wellbore under pressure from a pit or container at the surface by a pumping system at the surface. 
     In certain known mud pump systems, suction and discharge modules have valves therein that selectively control fluid flow through the module in an intake (suction) mode in which piston apparatus creates a vacuum drawing drilling fluid into the module and in an output mode (Discharge) in which the piston apparatus creates pressure forcing drilling fluid out of the module. In the suction mode, a suction valve opens allowing drilling fluid into the module while a discharge valve remains closed. In the discharge mode, the pressure of the drilling fluid closes the suction valve and opens the discharge valve. 
     Both valves, the suction valve and the discharge valve, are subjected to the erosive and damaging effects of the flow of drilling fluid. The drilling fluid contains drilled cuttings and debris which can erode valve parts (e.g. seats, stems, valve members, seals, guide bushings, insert, liners, wear plates etc.). Also, mud pumps which can pump relatively hot drilling fluid at, e.g., 500 to 2000 gallons per minute, force the erosive drilling fluid against the valve parts at high velocities which add to the fluid&#39;s damaging effects. 
     In many valves used in mud pump systems, a guide in the valve which is disposed across a flow path or guide fingers extending from a valve member into a valve seat guide a valve member so that valve member seats correctly and effectively against the valve seat. In many valves, the valve seat surface against which the valve member (or poppet) seats is, ideally, flat; and the surface of the valve member which sealingly abuts the flat seat surface of the valve seat is, correspondingly, and ideally, flat. A guide or guide fingers facilitates correct seating of the valve member&#39;s flat seating surface against the valve seat&#39;s flat seat surface. If either surface is not flat, or if one surface does not contact the other in a substantially parallel (flat surface to flat surface) manner, ineffective or inefficient valve operation may result. 
     The erosive and/or damaging effects of drilling fluid flow through a valve can damage the seating surfaces so that the ideal flat-surface-to-flat surface seating is not achieved. Also, the drilling fluid can damage a guide (e.g. ribs and a channel for receiving a stem or rod projecting from a valve member) or guide fingers so that the ideal surface seating is not achieved. In some instances, damage to a guide or to guide fingers results in a flat valve member surface contacting a flat seating surface at an angle so that effective valve closure is not possible or so that the valve is insufficiently closed for efficient operation. In some aspects, erosive drilling fluid flow renders initially-flat seating surfaces non-flat with resulting ineffective sealing and valve closure. 
     For these reasons in many mud pump systems, suction and discharge valves are repaired or replaced on a regular basis. 
     In many known mud pump valves, the valves are opened and closed by mechanically creating a vacuum or fluid pressure increase in the valve that overcomes a spring to allow a valve member to move. The movement of the valve member is not controlled, i.e., it is subject to a surge of fluid under pressure. As fluid pressure builds up to move a valve member, a corresponding amount of fluid builds up adjacent the valve. when the pressure is high enough, a relatively large charge of fluid goes through the valve at high velocity. This surge of fluid can have deleterious effects on valve parts. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention, in at least certain embodiments, discloses systems for pumping a drilling fluid mixture, the drilling fluid mixture containing drilling fluid and solids, the systems having: a pump apparatus; the pumping apparatus having a body with a pumping chamber, an inlet and an outlet; a suction valve in the body for selectively controlling flow of the drilling fluid mixture in through the inlet; a discharge valve in the body for selectively controlling flow of the drilling fluid mixture out through the outlet; and a dampener system according to the present invention in fluid communication with the pumping chamber. 
     Such a pump system according to the present invention, in one aspect, includes: a base; a housing connected to the base, the housing having an interior; a liner within the housing, the liner expandable in response to fluid pressure; a piston/cylinder apparatus in fluid communication with the housing; the piston/cylinder apparatus having a movable piston movable in response to fluid flowing from the housing to the piston/cylinder apparatus; a torsion apparatus movably connected to the base, the piston movable to contact and to move the torsion apparatus in response to fluid flowing from the housing to the piston/cylinder apparatus; and the torsion apparatus movable by the piston from a first static position to a second position to dampen pulsations of fluid into the pumping chamber. 
     In one aspect, a pumping system according to the present invention has a dampener system according to the present invention which includes: a housing, the housing having an interior; a deformable bladder within the housing, the deformable bladder in fluid communication with the pumping chamber; and the deformable bladder deformable in response to pressure variation in the pumping chamber. 
     The present invention discloses, in certain aspects, dampeners for drilling fluid pumping systems which suppress and/or eliminate the damaging effects of undesirable pulsations or surges of drilling fluid passing through the systems. In certain aspects, the dampener has a liner with liquid therein which expands and contracts in response to the pressure of drilling fluid passing through a pumping system. 
     The present invention discloses, in certain aspects, dampeners for drilling fluid pumping systems in which the dampener has a liner with liquid therein which expands and contracts in response to the pressure of drilling fluid passing through a pumping system. In certain aspects, a dampener according to the present invention has a torsion apparatus that absorbs and then releases energy to facilitate the dampening of drilling fluid surges. In other aspects, a dampener system according to the present invention has an inflatable bladder surrounded by an expandable spring member, both the bladder and the spring member responsive to drilling fluid surges to suppress deleterious effects of such surges. 
     The present invention discloses, in certain aspects, modules for a drilling fluid pumping system which include a dampener for suppressing and/or eliminating the damaging effects of undesirable pulsations or surges of drilling fluid passing through the modules. In certain aspects, the dampener is within a block of the module that also contains suction and discharge valve assemblies within a module block. 
     The present invention discloses, in certain aspects, a drilling fluid pumping system, also known as a mud pump system, for pumping drilling fluid or mud used in wellbore operations which has pumping modules with valves that have non-flat seating surfaces. In certain aspects, such valves have a valve member or poppet that is movable with multiple degrees of freedom in any of which effective seating of the valve member against a valve seat is achieved. In particular aspects of such a valve, dual sealing is achieved by sealing of a valve member against both a valve seat and against a seal disposed in a valve seat. 
     In certain particular aspects of a mud pump system according to the present invention, a mud pump valve has a tapered spring biased against a valve member which enhances the free seating movement of a valve member. 
     The present invention discloses, in certain aspects, valves for a system for pumping a drilling fluid mixture, the drilling fluid mixture containing drilling fluid and solids, the valves having: a seat with a valve seat surface; a valve member with a member surface, part of the valve member movable to seat the member surface against the valve seat surface to prevent the flow of the drilling fluid mixture past the valve seat; a cartridge stem positioned with respect to the valve member, and a valve actuator within the cartridge stem for selectively moving the valve member. In certain aspects, the present invention discloses a system for pumping a drilling fluid mixture, the drilling fluid mixture containing drilling fluid and solids, the system having: a pump apparatus; the pumping apparatus having a body with an inlet and an outlet; a suction valve in the body for selectively controlling flow of the drilling fluid mixture in through the inlet; a discharge valve in the body for selectively controlling flow of the drilling fluid mixture out through the outlet; and a dampener within the body for inhibiting pulsations of fluid pumped from the pump apparatus In certain valves according to the present invention a valve actuator is used which is pneumatically powered without certain mechanically moving parts used in prior valves. 
     Accordingly, the present invention includes features and advantages which are believed to enable it to advance pumping system technology. Characteristics and advantages of the present invention described above and additional features and benefits will be readily apparent to those skilled in the art upon consideration of the following description of preferred embodiments and referring to the accompanying drawings. 
     Certain embodiments of this invention are not limited to any particular individual feature disclosed here, but include combinations of them distinguished from the prior art in their structures, functions, and/or results achieved. Features of the invention have been broadly described so that the detailed descriptions of embodiments preferred at the time of filing for this patent that follow may be better understood, and in order that the contributions of this invention to the arts may be better appreciated. There are, of course, additional aspects of the invention described below and which may be included in the subject matter of the claims to this invention. Those skilled in the art who have the benefit of this invention, its teachings, and suggestions will appreciate that the conceptions of this disclosure may be used as a creative basis for designing other structures, methods and systems for carrying out and practicing the present invention. The claims of this invention are to be read to include any legally equivalent devices or methods which do not depart from the spirit and scope of the present invention. 
     What follows are some of, but not all, the objects of this invention. In addition to the specific objects stated below for at least certain embodiments of the invention, other objects and purposes will be readily apparent to one of skill in this art who has the benefit of this invention&#39;s teachings and disclosures. It is, therefore, an object of at least certain preferred embodiments of the present invention to provide new, useful, unique, efficient, nonobvious dampener systems for drilling fluid pumping systems and methods of their use; 
     Such dampener systems with a torsion apparatus for damping undesirable fluid pulsations; and 
     Such dampener systems with a deformable bladder for damping undesirable fluid pulsations. 
     The present invention recognizes and addresses the problems and needs in this area and provides a solution to those problems and a satisfactory meeting of those needs in its various possible embodiments and equivalents thereof. To one of skill in this art who has the benefits of this invention&#39;s realizations, teachings, disclosures, and suggestions, various purposes and advantages will be appreciated from the following description of certain preferred embodiments, given for the purpose of disclosure, when taken in conjunction with the accompanying drawings. The detail in these descriptions is not intended to thwart this patent&#39;s object to claim this invention no matter how others may later attempt to disguise it by variations in form, changes, or additions of further improvements. 
     The Abstract that is part hereof is to enable the U.S. Patent and Trademark Office and the public generally, and scientists, engineers, researchers, and practitioners in the art who are not familiar with patent terms or legal terms of phraseology to determine quickly, from a cursory inspection or review. the nature and general area of the disclosure of this invention. The Abstract is neither intended to define the invention, which is done by the claims, nor is it intended to be limiting of the scope of the invention or of the claims in any way. 
     It will be understood that the various embodiments of the present invention may include one, some, or all of the disclosed, described, and/or enumerated improvements and/or technical advantages and/or elements in claims to this invention. 
     Certain aspects, certain embodiments, and certain preferable features of the invention are set out herein. Any combination of aspects or features shown in any aspect or embodiment can be used except where such aspects or features are mutually exclusive. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A more particular description of embodiments of the invention briefly summarized above may be had by references to the embodiments which are shown in the drawings which form a part of this specification. These drawings illustrate embodiments preferred at the time of filing for this patent and are not to be used to improperly limit the scope of the invention which may have other equally effective or legally equivalent embodiments. 
         FIG. 1  is a schematic view, partially cutaway, of a system according to the present invention. 
         FIG. 1A  is a schematic view of a mud pump system according to the present invention. 
         FIG. 2A  is a perspective view of a pump apparatus according to the present invention. 
         FIG. 2B  is a side view of a pump apparatus of  FIG. 2A . 
         FIG. 2C  is a perspective view of part of the apparatus of  FIG. 2A . 
         FIG. 2D  is a perspective view of part of the apparatus of  FIG. 2C . 
         FIG. 2E  is a top cross-section view of the part of the apparatus of  FIG. 2C . 
         FIG. 2F  is a perspective view, partially cutaway, of a pump module according to the present invention with valve assemblies according to the present invention. 
         FIG. 2G  is a perspective view of two valve assemblies according to the present invention. 
         FIG. 2H  is a side view of the valve assemblies of  FIG. 2G . 
         FIG. 2I  is a cross-section view of the valve assemblies of  FIG. 2G . 
         FIG. 3A  is a perspective view of a valve assembly according to the present invention. 
         FIG. 3B  is a cross-section view of the valve assembly of  FIG. 3A . 
         FIG. 4  is a side perspective view, partially cutaway, of part of the valve assembly of  FIG. 3A . 
         FIG. 5  is a perspective view of an actuator of a valve assembly as in  FIG. 3A . 
         FIG. 6  is a side view of a spring according to the present invention. 
         FIG. 7A  is a perspective view of a spring according to the present invention. 
         FIG. 7B  is another perspective view of the spring of  FIG. 7A . 
         FIG. 8A  is a side view, partially cutaway, showing a step in the operation of a valve according to the present invention of the system of  FIG. 7A . 
         FIG. 8B  is a side view, partially cutaway, showing a step in the operation of the valve of  FIG. 8A  showing a step following the step of  FIG. 8A . 
         FIG. 9A  is a side view, partially cutaway, of a system according to the present invention. 
         FIG. 9B  is a side view, partially cutaway, of a system according to the present invention of  FIG. 9A  with an open valve. 
         FIG. 9C  is a side cross-section view of a poppet of the system of  FIG. 9A . 
         FIG. 9D  is a side cross-section view of a poppet in a system according to the present invention. 
         FIG. 9E  is a side cross-section view of a poppet in a system according to the present invention. 
         FIG. 10A  is a side view of a poppet and spring for systems according to the present invention. 
         FIG. 10B  is a cross-section view of the poppet and spring of  FIG. 10A . 
         FIG. 10C  is a cross-section view of the poppet and spring of  FIG. 10A . 
         FIG. 11A  is a side view of a support of the poppet of  FIG. 10A . 
         FIG. 11B  is a top view of the support of  FIG. 12A . 
         FIG. 11C  is a bottom view of the support of  FIG. 12A . 
         FIG. 12  is a perspective view of the spring of  FIG. 10A . 
         FIG. 13A  is a perspective view of a mud pump module with a dampener system according to the present invention. 
         FIG. 13B  is another perspective view of the module of  FIG. 13A . 
         FIG. 13C  is a cross-section view of the dampener of the module of  FIG. 13A . 
         FIG. 13D  is a perspective view of part of the dampener of  FIG. 13C . 
         FIG. 13E  is an end view of the part of  FIG. 13D . 
         FIG. 13F  is a top view of the part of  FIG. 13D . 
         FIG. 13G  is an end view of the part opposite the end of  FIG. 13E . 
         FIG. 13H  is an enlarged cross-section view of part of the dampener of  FIG. 13C . 
         FIG. 13I  is an enlarged cross-section view of part of the dampener of  FIG. 13C . 
         FIG. 13J  is a cross-section view of the dampener of the module of  FIG. 13A . 
         FIG. 13K  is a cross-section view of the dampener of the module of  FIG. 13A . 
         FIG. 13L  is a cross-section view of part of the dampener as shown in  FIG. 13K . 
         FIG. 13M  is a cross-section view of part of the dampener as shown in  FIG. 13J . 
         FIG. 14A  is a perspective view of a housing or “bottle” of the dampener of  FIG. 13C . 
         FIG. 14B  is an end view of the bottle of  FIG. 14A . 
         FIG. 14C  is a perspective view of the bottle of  FIG. 14A . 
         FIG. 15A  is a perspective view of a liner of the dampener of  FIG. 13C . 
         FIG. 15B  is a front view of the liner of  FIG. 15A . 
         FIG. 15C  is a side view of the liner of  FIG. 15A . 
         FIG. 15D  is a cross-section view of the liner of  FIG. 15A . 
         FIG. 15E  is a cross-section view of the liner of  FIG. 15A . 
         FIG. 16A  is a cross-section view of part of the dampener of  FIG. 13C . 
         FIG. 16B  is an enlargement of part of the dampener as shown in  FIG. 16A . 
         FIG. 16C  is an enlargement of part of the dampener as shown in  FIG. 16A . 
         FIG. 16D  is an enlargement of part of the dampener as shown in  FIG. 16C . 
         FIG. 16E  is an enlargement of part of the dampener as shown in  FIG. 16A . 
         FIG. 16F  is an enlargement of part of the dampener as shown in  FIG. 16E . 
         FIG. 17A  is a perspective view of a valve assembly of the dampener of  FIG. 13C . 
         FIG. 17B  is a perspective view of a valve assembly of the dampener of  FIG. 13C . 
         FIG. 18A  is a perspective view of a mud pump module with a dampener according to the present invention. 
         FIG. 18B  is a top view of the module of  FIG. 18A . 
         FIG. 18C  is a side view of the module of  FIG. 18A . 
         FIG. 18D  is a perspective view of the module of  FIG. 18A . 
         FIG. 19A  is a perspective view of a dampener of the module of  FIG. 18A . 
         FIG. 19B  is a cross-section view of the dampener of  FIG. 19A . 
         FIG. 19C  is a cross-section view of the dampener of  FIG. 19A . 
         FIG. 19D  is a cross-section view of the dampener of  FIG. 19A . 
         FIG. 19E  is a cross-section view of the dampener of  FIG. 19A . 
         FIG. 20A  is a perspective view of a top cover of the dampener of  FIG. 19A . 
         FIG. 20B  is a bottom perspective view of the top cover of  FIG. 20A . 
         FIG. 20C  is a side cross-section view of the top cover of  FIG. 20A . 
         FIG. 21A  is top perspective view of an intermediate cover of the dampener of  FIG. 19A . 
         FIG. 21B  is a bottom perspective view of the cover of  FIG. 21A . 
         FIG. 21C  is a side cross-section view of the cover of  FIG. 21A . 
         FIG. 22A  is perspective view of a bladder of the dampener of  FIG. 19A . 
         FIG. 22B  is a cross-section of the bladder of  FIG. 22A . 
         FIG. 22C  is a bottom perspective view of the bladder of  FIG. 22A . 
         FIG. 22D  is bottom view of the bladder of  FIG. 22A . 
         FIG. 23A  is a perspective view of a housing of the dampener of  FIG. 19A . 
         FIG. 23B  is a cross-section view of the housing of  FIG. 23A . 
         FIG. 23C  is a cross-section view of the housing of  FIG. 23A . 
         FIG. 23D  is a partial cross-section view of the housing of  FIG. 23A . 
         FIG. 23E  is a partial cross-section view of the housing of  FIG. 23A . 
         FIG. 24A  is a perspective view of a spring of the dampener of  FIG. 19A . 
         FIG. 24B  is a perspective view of the spring of  FIG. 24A . 
         FIG. 24C  is a perspective view of the spring of  FIG. 24A . 
         FIG. 24D  is a perspective view of the spring of  FIG. 24A . 
         FIG. 25A  is a perspective view of a ring of the dampener of  FIG. 19A . 
         FIG. 25B  is a perspective view of the ring of  FIG. 25A . 
         FIG. 25C  is a perspective view of the ring of  FIG. 25A . 
         FIG. 25D  is a perspective view of the ring of  FIG. 25A . 
         FIG. 26A  is a cross-section view of the housing of the dampener of  FIG. 19A . 
         FIG. 26B  is a partial view of the housing as shown in  FIG. 26A . 
         FIG. 26C  is a partial view of the housing as shown in  FIG. 26A . 
         FIG. 26D  is a bottom perspective view of the bladder as shown in  FIG. 26A , 
         FIG. 26E  is a bottom view of the bladder as shown in  FIG. 26A   
     
    
    
     Certain embodiments of the invention are shown in the above-identified figures and described in detail below. Various aspects and features of embodiments of the invention are described below and some are set out in the dependent claims. Any combination of aspects and/or features described below or shown in the dependent claims can be used except where such aspects and/or features are mutually exclusive. It should be understood that the appended drawings and description herein are of certain embodiments and are not intended to limit the invention or the appended claims. On the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the invention as defined by the appended claims. In showing and describing these embodiments, like or identical reference numerals are used to identify common or similar elements. The figures are not necessarily to scale and certain features and certain views of the figures may be shown exaggerated in scale or in schematic in the interest of clarity and conciseness. 
     As used herein and throughout all the various portions (and headings) of this patent, the terms “invention”, “present invention” and variations thereof mean one or more embodiments, and are not intended to mean the claimed invention of any particular appended claim(s) or all of the appended claims. Accordingly, the subject or topic of each such reference is not automatically or necessarily part of, or required by, any particular claim(s) merely because of such reference. So long as they are not mutually exclusive or contradictory any aspect or feature or combination of aspects or features of any embodiment disclosed herein may be used in any other embodiment disclosed herein. 
     DETAILED DESCRIPTION OF THE INVENTION 
     The system  500  shown in  FIG. 1  includes a derrick  502  from which extends a drillstring  504  into the earth  506 . The drillstring  504 , as is well known, can include drill pipes and drill collars. A drill bit  512  is at the end of the drillstring. A rotary system  514 , top drive system  526 , and/or a downhole motor  532  (“fluid motor”, “mud motor”) may be used to rotate the drillstring  504  and the drill bit  512 . A typical drawworks  516  has a cable or rope apparatus  518  for supporting items in the derrick  502 . A mud pump system  522  according to the present invention with one, two, three-to-ten, or more mud pumps  521  according to the present invention each with pumping modules with one or two valves according to the present invention supplies drilling fluid  524  to the drillstring  504 . Drilling forms a wellbore  530  extending down into the earth  506 . Each mud pump  521  has at least one valve  501  according to the present invention or (as shown in  FIG. 1A  schematically) multiple pumping modules  503  each with a suction valve  505  according to the present invention and a discharge valve  506  according to the present invention. Each mud pump  521  has a main crank shaft  521   c.    
     During drilling, the drilling fluid  524  is pumped by pump(s)  521  of the mud pump system  522  into the drillstring  504  (thereby operating a downhole motor  532  if such an optional motor is used). Drilling fluid  524  flows to the drill bit  512 , and then flows into the wellbore  530  through passages in the drill bit  512 . Circulation of the drilling fluid  524  transports earth and/or rock cuttings, debris, etc. from the bottom of the wellbore  530  to the surface through an annulus  527  between a well wall of the wellbore  530  and the drillstring  504 . Cuttings and debris are removed from the drilling fluid  524  with equipment and apparatuses not shown, and it is re-circulated from a mud pit or container  528  by the pump(s) of the mud pump system  522  back to the drillstring  506 . Also, some desirable solids may be added to the drilling fluid. 
     A system  10  according to the present invention as shown in  FIGS. 2A and 2B  has a main housing  12  mounted on a base  8  with an optional crane system  20  for lifting and moving system parts. A pedestal  21  of the crane system  20  is rotatably mounted on a bearing assembly  22  on the housing  12 . A lift apparatus  23  is movably mounted on a beam  24  and a support  25  extends down from the lift apparatus  23 . A chain hoist lift may be used with the structure shown which is attached to the support  25 . Motors  14  each drive pinions  16  which in turn drive a drive gear  18  (see  FIG. 3C ) to move pistons  19  for six removable pump modules  650  (as described below; may be any module disclosed herein and/or may have any valve assembly or valve assemblies disclosed herein). A pressure relief apparatus (e.g. one or more relief valves) is provided for the modules  650  and, as shown, in one aspect, for each of the six modules  650  there is a pressure relief valve  13 . Optional rails  15  project up from the housing  12 . 
     An oil pump  2  pumps lubricating oil to various parts of the system. A water pump  4  pumps water to a filtration system (not shown) and a cooler (not shown). The pumps are mounted on pump mounts  8   b  connected to the base  8 . Doors  3  and  5  (one each for each pump system  30 ) provide access to various internal parts of the system  10 . Drilling fluid enters the system  10  through an inlet  7  and is pumped out via the modules  650  to a main outlet  9 . 
     The modules  650  have a body  602  with a first bore  602   a  and a second bore  602   b . A discharge valve assembly according to the present invention is in the first bore and a suction valve assembly according to the present invention is in the second bore. With a piston fluid is pumped into a chamber  652  of the module  650  via an inlet port  604  and is discharged from the module  650  into a discharge conduit  634  via an outlet port  606 . 
       FIG. 2F  shows the relative positions of two valve assemblies  100   a ,  100   b  (like the valve assembly  100 ) according to the present invention as they are present in a block of a mud pump module. The valve assemblies  100   a ,  100   b  (which may be any valve assemblies disclosed herein) are in bores  642 ,  643 , respectively, in a block  644 . The block  644  can be used in a system like that of  FIG. 2A . 
       FIGS. 2G-2I  show two valve assemblies  100   x ,  100   y  (like the valve assembly  100   a ,  FIG. 9A ; may be any valve assembly according to the present invention) as they are disposed in a block B (shown in dotted line; may be any suitable block or body; including, but not limited to, the body  602  or block  644  referred to above) of a mud pump system. Fluid is sucked in by action of the suction valve assemblies  100   x  through a suction inlet  400  and discharged by action of the discharge valve assembly  100   y  through a discharge outlet  402 . The fluid is received in a pumping chamber  404 . 
     Fluid pumped from the chamber  404  can impact parts of the discharge valve  100   x . Optionally, an accumulator/dampener  410 , positioned within the block B, is in fluid communication with the pumping chamber  404 . The accumulator/dampener  410  reduces undesirable pulsations of fluid under pressure from the pumping chamber  404 . Any suitable known accumulator/dampener may be used. 
       FIGS. 3A and 3B  show a valve assembly  100  according to the present invention which can serve as a suction valve or a discharge valve for a mud pump system (e.g., but not limited to, the suction valve assembly  680  and the discharge valve assembly  630  described above; or the suction valve  100   x  and the discharge valve  100   y  described above).  FIG. 4  shows top portions of the valve assembly  100 . 
     The valve assembly  100  has a hollow cartridge stem  102  with an interior channel  104  within which are located a valve actuator  130  and an adapter  106 . A spring support  108 , connected to a flange  110  of the cartridge stem  102 , has an end  112  which is encompassed by part of an expansion spring  120  an end of which abuts the spring support  108 . 
     A poppet (or curved valve member)  114  rests on a support  116 . An end  122  of the spring  120  abuts and is biased against a bottom of the support  116 . A ball  118  rests on a ball support  124  which rests on the support  116 . A cable  128  (i.e. a non-rigid connector) (made of any known cable material) connected to the ball  118  passes through a hole  140  in and through the support  124 , through a hole  142  in the support  116 , through the spring  120 , through a hole  143  in the spring support  108 , through a hole  144  in the adapter  106  which is and is connected to the adapter  106  connected to an actuator  130 . 
     A washer  151  above the ball  118  abuts an underside  115  of the poppet  114 . A recess  152  within the poppet  114  houses the ball  118 , the washer  151  and the support  124 . The poppet  114  has a tapered surface  136  for sealingly abutting a valve seat and a seal of a valve seat as described below. 
     The poppet  114  is movable toward and away from a valve seat  160 . The valve seat  160  has a channel  162  for fluid flow therethrough. The poppet  114  selectively closes off and opens up the channel  162  to fluid flow. Part of the channel  162  is sized and configured for the poppet  114 . A surface  166  of the valve seat  160  is positioned to seal against the tapered of the surface  136  of the poppet  114 . Optionally, there are no guide fingers projecting from the poppet  114  (although it is within the scope of the present invention to use them); and there are no arms or ribs across the valve seat (it is unobstructed) for receiving and stabilizing a rod, stem or neck projecting from a poppet; and there is no rod, neck or stem projecting from the poppet. Thus, flow through the channel  162  is unobstructed by such parts which are present in many prior valves. 
     A recess  168  around the valve seat  160  holds a seal  169 . Part of the surface  136  of the poppet  114  sealingly abuts the seal  169  when the valve assembly is closed, preventing fluid flow. Thus dual sealing is achieved. 
     The poppet  114  has a range of freedom of movement within the channel  162  of the valve seat  160 . However the poppet  114  is located within and with respect to the valve seat  160 , part of the outer tapered surface  136  of the poppet  114  will sealingly abut the seal  169  and the surface  136  will sealingly abut the surface  166 . The poppet  114  can be aligned (or not) with the valve seat  160 , but either way an effective seal is maintained with part of the surface  136  sealed against the seal  169 . Movement of the poppet  114  on the ball  118  and the sizing and configuration of the various parts contribute to permissible freedom of movement of the poppet  114  without sacrificing the sealing necessary to close the valve assembly. 
       FIG. 5  shows the valve actuator  130  which can be, in certain aspects, any suitable known controllable, valve actuator, e.g., but not limited to “muscle” apparatuses, pneumatic cylinder actuators, hydraulic cylinder actuators, and electromagnetic actuators. 
     In one aspect, as shown in  FIG. 5 , the valve actuator  130  is a controlled, pneumatically powered actuator known as a FESTO (TRADEMARK) “muscle” actuator. The actuator  130  has an expandable hose  132  mounted between two bases  134 ,  135 . Air under pressure is introducible into the interior of the hose  132  through a channel  137  in a pneumatic coupling  139 . The upper base  134  is connected to an adapter support  127  to which the adapter  106  is secured. 
     As shown in  FIG. 5 , air under pressure has not yet been applied within the hose  132 . Once air is applied the hose moves outwardly, effectively moving the top base  134  toward the lower base  135  and thereby pulling the adapter  106  to pull the cable  128  and move the poppet  114  out of sealing contact with the valve seat  160  against the force of the spring  120 . 
       FIG. 6  shows one embodiment, a spring  120   a , of a spring  120 . As compared to prior known spring designs, the spring  120   a  has a spring body with a smaller spring diameter, a, and with a higher spring force; but the wire diameter is relatively large, e.g. 0.22 inches, which results in the higher spring force. Use of an actuator like the actuator  130 ,  FIG. 5 , makes it possible to use a spring with the increased spring force (with the increased wire diameter). The overall diameter, b, of the spring  120   a  is relatively smaller than prior springs because the spring  120   a  does not have to accommodate the relatively large necks of certain prior valve members. Certain prior mud pump valve springs reached a known resonant frequency (e.g. about 40 Hz to 43 Hz) creating poppet oscillations that resulted in an improperly seated poppet and in fluid pulsations transmitted downstream of a valve assembly. Due to its size and weight, the spring  120   a  has a higher natural frequency than those prior springs which resonate around 40 Hz and, thus, more force is required to resonate the spring  120   a . In certain aspects the spring  120  (or  120   a ; or the spring  120   b ,  FIG. 7A ) is sized and configured so its natural resonant frequency is about 25% higher than that of certain known springs (e.g., in one aspect 50 Hz vs 43 Hz). This reduces the chance of flow-induced resonance in the valve assembly with such a spring; provides better, more stable control of the valve assembly&#39;s poppet; and provides more positive seating of the poppet against the valve seat. 
       FIGS. 7A and 7B  show a spring  120   b  according to the present invention which has a spring body  120   c  and an end tapered portion  120   d  which abuts a support (e.g. like the support  116 ,  FIG. 3A ). The tapered portion  120   d , since it is narrower than a base  120   e  of the spring  120   b , contributes to the freedom of movement of the poppet  114  (e.g. as in  FIG. 8A ). 
       FIGS. 8A and 8B  illustrate steps in the operation of a valve assembly  100  (which has a spring  120   b , although any suitable spring may be used). As shown in  FIG. 8A , air under pressure has not yet been applied within the hose  132  and the and the spring  120   b  urges the poppet  114  into sealing contact with the seal  169  and with the valve seat  160 . The valve assembly  100  is closed to fluid flow therethrough. Fluid pressure also forces the poppet against the valve seat. On the discharge side of the valve seat at the beginning of the pumping/compression part of a cycle, the spring  120   b  and the fluid within a discharge manifold pushes the poppet  114  against the seat. This continues until the pressure within the discharge manifold drops below the pressure within the pumping cylinder and/or until the actuator  130  is commanded to open. On the suction side, the fluid within the pumping cylinder pushes the poppet  114  against the seat  160  again during the compression part and until the actuator  130  is commended to open the valve. When the “muscle” of the actuator  130  is not expanded, there is residual air trapped between the commanding valve and the actuator  130 . The pressure of this trapped air is close to the pressure that existed in this line at the moment of exhausting the air and closing off the valve&#39;s exhaust port. When the actuator is flexed, there is air at a pressure that is sufficient to open the valve, e.g. 110 psi. The actuator and air lines are filled in order to decrease the actuator&#39;s response time—the time to respond to a commanding pressure. If the actuator is completely empty or, with, e.g. air at atmospheric pressure, it will take slightly longer for the actuator to respond, because when such a high pressure is applied the cavity would have to be filled with air first, then compress the air just introduced to a high enough pressure to barely stretch the hose  132  and only after that will the hose  132  change its length or respond to a commanding pressure. 
     As shown in  FIG. 8B , air under pressure from an air supply  200  (with a proportional control valve  200   p ) has been applied within the hose  132  causing it to expand and pulling the cable  128  away from the valve seat  160 . In so doing, the poppet  114  is moved out of sealing contact with the seat  160  and the seal  169  of the valve seat  160  and the valve assembly is opened to fluid flow permitting fluid to flow into and out from a mud pump module housing the valve assembly. 
     It is advantageous that the poppet is part of the valve cartridge. During assembly, when the pump is assembled for the first time, it is much easier to have a preassembled valve cartridge and, without adjustments, to insert and bolt it in and have it immediately become functional. Moreover, in servicing the valve, it is much easier to extract the entire cartridge, versus bits, individual parts, and/or pieces. In certain current designs, a poppet/valve has a pseudo cartridge design in the sense that the valve has no restricting elements to keep it attached to the cartridge. In other words, the cartridge can be loosely put together prior to assembly and it can be inserted as a cartridge being secured to the body by bolts. However, if during this assembly process, or later on during servicing the valve, this cartridge is turned upside down, the valve itself can become loose and fall to the ground. 
     Often in such prior systems there is no element like a snap ring to secure the valve to the cartridge. It is also advantageous that the seal is part of the valve housing. It is easier to have the seat part of a block that can be preassembled to the pump and, later on, during a later step in manufacturing, to bolt on to it a subassembly like the valve cartridge. 
     In designs according to the present invention, seals, e.g. the seal  169 , do not resonate. According to the present invention, such seals are surrounded by a support and have no extraneous or “banging” features which could be excited by a surrounding flow stream. 
     In certain aspects according to the present invention, poppets and seats are made of ceramics which do not rust. In certain particular aspects, an alumina based ceramic offers very high strength and good wear resistance. In other aspects, a boron carbide ceramic can be used which has excellent erosion wear resistance. Both of these two ceramics have a higher erosion resistance then steel. In certain aspects the poppets of assemblies according to the present invention are made with a steel core surrounded by a ceramic. The steel core supports the Belleville washers and can have cut threads into it. A ceramic outer skin provides erosion resistance. In certain aspects, the special profiles facilitate the flow opening and closing the valve gradually. 
     In certain current designs, valves have two parallel surfaces. Often these surfaces form a seal that is part of conical bodies; i.e. the seal has a conical machined surface against which is pushed a poppet. The poppet&#39;s sealing surface is also conical so that, at every instance, the seat&#39;s and poppet&#39;s sealing surfaces are parallel. During discharge, when the two bodies are separating and, thus, allowing the fluid to flow from the pumping chamber into the discharge manifold, the fluid is squeezed in between these flat surfaces. During this phase the fluid&#39;s velocity can be greatly increased as it passes from a large cross section of the pumping chamber into a small one with parallel surfaces of the valve&#39;s passage way. Moreover, because there is no controlling actuator, such a valve can open suddenly when the fluid&#39;s pressure exerts onto the valve&#39;s face a force slightly higher than that developed by the spring acting on the opposite face. As the fluid leaves at high velocity, it enters into a larger cross section that is the discharge manifold The high velocity and energy fluid acts almost like a piston in this case and pushes an adjacent block of fluid along the discharge line. This sudden move of a significant block of fluid can create a “bang” or a specifically loud noise almost like a pounding. This repeated banging/pounding can have detrimental effects on the drill line or other equipment. 
     In certain valve assemblies according to the present invention, the flat parallel surfaces are replaced by curved ones. Additionally, there is a controlling actuator that can open the valve before pressure in the pumping chamber reaches a value high enough to counteract the spring and, thus, to open the vale. Pressure at which the fluid leaves the pumping chamber is greatly reduced. Being formed in between two curved surfaces, the valve&#39;s passage way flow characteristics do not impart a high velocity/energy to the fluid stream. Consequently, the fluid enters and leaves the discharge manifold and line respectively in a more dispersed manner. There is no “bang” as in certain previous valves because the fluid does not flow in discrete “blocks”. 
     The control system CS controls the air supply  200  and, thus, controls the valve assembly  100 . This is in contrast to prior valves in which fluid flow opens and closes the valve. In one aspect, the control system controls the speed with which the parts move and thereby controls the speed of opening and of closing off the valve. Using appropriate software programming of programmable media in the control system, the control system controls an electro proportional valve control (e.g. the valve  200   p .  FIG. 8B ) that, in turn, controls the amount of air that enters or leaves the actuator  132 . Consequently, the control system controls how fast, how long and how much the valve is opened. Gradual opening and closing is possible which reduces pressure pulsations. Each pump shaft (crankshaft) may have a speed sensor in communication with the control system (e.g. a sensor  521   s ,  FIG. 1 ). In systems with electric motors that drive the crankshaft(s), the motors are commanded through software in the control system and the same speed control signal can be broadcast to the control system. A dedicated speed sensor or a linear displacement transducer installed in every cylinder provides information for a closed loop control system (usable, e.g., to diagnose a pump in case of failure). With valve assemblies according to the present invention, the valves are not connected to the crankshaft. 
     The control system has programmable media, e.g. in a computer, computers, and/or PLC(s). In one aspect, the control system is preloaded with a program that includes a defining equation and a curve fitter. The defining equation is a function of pump shaft speed. The curve fitter compares the curve generated by the defining equation with an “ideal” curve desired to drive the valve The ideal curve usually represents the valve&#39;s speed, or acceleration, or opening and/or, a different relevant parameter plotted versus time. The output from the control system drives a proportional valve, a valve that controls the actuator  130 , e.g., in one aspect, supply air into a FESTO (TRADEMARK) “muscle”. Thus, the valve being actuated closely follows the preprogrammed curve/equation and the valve opens or closes at a certain velocity or acceleration, or that it opens at a certain rate over the duration of a pumping cycle. The opening or closing rate can be constant or variable. That is, the valve can start opening at a certain low rate followed by a higher rate followed by a different rate, and so on. 
     In one aspect, during a cycle the valve tends to follow a certain bell-shaped curve. Thus, the valve starts opening at a low rate followed at the very next instance by a slightly higher rate and in the next instance by an even higher rate and so on. All this is followed on the descending side of the curve by a lower rate followed by a slightly lower rate and so on until the valve closes. By introducing or expelling fluid into or from the pumping chamber at certain times the pump&#39;s behavior is changed or the pump&#39;s flow is measurable. 
     The mechanical equivalent of controlling a valve&#39;s opening rate is a cam. The cam, through its profile, controls how fast and in what relationship relative to another element, e.g. a crankshaft, the valve will open or close. In other words, it controls the valve&#39;s rate (displacement versus time). However, a cam&#39;s profile can not be changed very easily because it is cut in metal. A practical method is to introduce a hydraulically actuated push rod or cam follower in between the cam and valve. Thus, the rate can change at will within a limited range. In the control strategy according to the present invention there is no piece of hardware/cam that limits the valve&#39;s rate. Consequently, in the proposed actuation and control strategy, the desired curve can be changed on the fly as long as the controller, e.g. a computer or PLC, can accept/support it. Programmability makes this equivalent to an infinitely variable profile cam shaft and the pump&#39;s output flow and vibration can be controlled. (An undesirable consequence of output flow in certain prior systems is component failure, e.g. due to cavitation.) 
     With the curved mating sealing surfaces of the valve seat and poppet, any contact results in an effective seal. Pressure fluctuations generated in or by prior art valves are reduced or eliminated and valve control reduces pressure fluctuation in the discharge line during pump operation. 
     Systems according to the present invention provide a fail safe mode. If a valve assembly according to the present invention that is inserted fails, then, for safety reasons, the pump continues working at either reduced or normal parameters until it is safe to stop it for service. In systems according to the present invention, if the actuator fails, e.g. if the muscle fails, it breaks or bursts, the valve will operate unrestricted (e.g. as a current known design valve). Thus, the pump can continue working at almost the same parameters until it is safe to stop it. 
       FIGS. 9A and 9B  show a valve assembly  100   a , like the valve assembly  100  (like numerals indicate like parts) with a spring  120   b  and a poppet  114   a . The poppet  114   a  has a nose  114   n  projecting from a poppet body  114   b . The nose  114   n  projects into the flow channel  162  of the valve seat  160 . In certain aspects, in systems according to the present invention the surface on the valve seat becomes, advantageously, more elastic. In a seal, two surfaces or edges are pushed against each other by a force. This acting force can be perpendicular to or at an arbitrary angle relative to the sealing surfaces. In systems according to the present invention the sealing bodies are the rubber seal and the poppet in one instance and, the seat itself and the poppet in a second instance. During a valve closing cycle, the first seal occurs in between a rubber O-ring and poppet. The acting force is axial relative to the poppet, but it is at an angle relative to the edge of contact between the two curved surfaces of the O-ring and poppet respectively. When the two bodies come into contact, at the point of contact, the vector components of this acting force are a normal to curved surfaces component and a tangential to curve components. This tangential component will stretch the rubber (the over hanging part of it) instead of purely compressing it. With the rubber O-ring being surrounded/supported by the seat&#39;s rigid body, the rubber will take a very high force in compression as the normal-to-curved surfaces vector component. The rubber becomes difficult to compress when it is surrounded by a rigid wall. Thus a mechanical maze is formed and, thus, the fluid encounters a high flow resistance. There is a sequence of high pressure (inside the pumping chamber), followed by a no flow area (where the rubber O-ring contacts the poppet), followed by a low pressure area (right after the rubber seal) and finally, followed by a no flow area at a contact between the poppet and the seat. Also, the shape of the deformed rubber O-ring at the leading edge toward the impinging fluid does not allow the fluid to enter in between the poppet and seal. 
     Valve “shivering” occurs when a valve is not actuated (pushed or pulled onto its seat) with a high enough force, and flow induced forces fully or partially unseat or seat the valve in a rapid sequence. Thus, the valve can not fulfill its primary function of separating two cavities. In systems according to the present invention, the actuator working against a spring reduces or eliminates valve “shivering” because two main forces are acting upon the valve&#39;s poppet—the force generated by a compressed spring and, in opposite direction, the force developed by the FESTO (TRADEMARK) “muscle” or an equivalent actuator  132 . Secondary forces that are pulling and pushing the poppet are those flow induced because of the high mainly axial forces generated by the two components, spring and actuator, any minute force variation induced by flow is counteracted by either one of the two large forces. The spring will oppose the motion if a minute variation will try pushing the poppet or to unseat it. Conversely, the actuator will oppose any pulling or seating of the poppet; and thus the poppet has a very stable attitude in flow. 
       FIG. 9B  shows the actuator  130  activated; air applied to the hose  132  has expanded the hose  132  making it contract down, thereby, unseating the poppet  114   a  from the valve seat  160 . 
     A valve assembly according to the present invention with a poppet like the poppet  114   a  provides uniform and stable poppet positioning and movement.  FIG. 9D  illustrates a velocity profile of incoming fluid E flowing around a poppet  114   a . Two rings A of high velocity fluid flow surround the poppet  114   a . The rings A are continuously and uniformly distributed all around the poppet  114   a , creating elastic cushions B that surround and stabilize the poppet  114   a , e.g. in the event of a disturbing force acting in a direction other than in an axial direction. A reverse fluid flow C (part of the flow E which has changed direction) acting on a back side of the poppet  114   a  tends to push the poppet  114   a  into the closed position shown against the incoming flow E and against the two elastic cushions B. The uniformity and distribution of the flow C also facilitate the maintenance of the poppet  114   a  in a stable attitude. 
       FIG. 9E  illustrates pressure distribution of an incoming flow E around the poppet  114   a . High pressure elastic fluid cushions D that surround and stabilize the poppet  114   a . The incoming flow E has a smooth transition around the nose  114   m  of the poppet  114   a  and the ensuing flow sticks (binds to or tends to flow along adjacent a curved surface) to the curved poppet surfaces. A reverse flow C will not suffer a sudden change in direction, but a gradual one (e.g. as illustrated by the curved arrows W of the flow C at the back of the poppet). In certain prior valves such a flow hits a poppet&#39;s back surface and flows at or near a ninety degree angle to the back of the poppet. Wobbling of the poppet  114   a  is reduced or eliminated and it will maintain a stable position with its vertical axis concentric with that of the tubular within which it is positioned. 
     In contrast, in certain prior art valve assemblies with typical plain rounded-head poppets, there are sudden ninety degree changes of fluid flow direction on both faces of the poppets. Sudden changes in the direction of fluid flow, as well as turbulence behind the poppet, can generate some flow-induced destabilizing forces. Also, with such typical plain rounded-head poppets with relatively large flat end surfaces, two areas of low pressure (vacuum or close to vacuum) are developed around sharp edges of the poppets. These areas are within and surrounded by high pressure. This pressure distribution can lead to cavitation and unstable attitude in flow. Also, discrete veins of flow can occur where these low pressure areas take place. Consequently, because of a non-uniform distribution around the body, the poppets will have a precession motion. This effect is amplified by the geometrical dimensions of the poppets. Non-uniform flow distribution results on the poppets back sides. 
       FIGS. 10A-10D  illustrate a poppet  114   b  on a base  114   s  on a spring  120   c  (see also  FIG. 13 ) according to the present invention. The spring  120   c  has an end  120   g  with projections  120   k . Optionally, there are one or three projections  120   e  The projections  120   k  have curved portions  120   m  which enhance freedom of movement of the poppet  114   b  so it can be self-centering. It is within the scope of the present invention to at least one, one, two, or more projections  120   k.    
     A pin  120   f  rests in a recess  120   r  of a support  120   h . The pin  120   f  projects through openings in the projections  120   k  to secure the spring  120   c  to the support  120   h . A cable (not shown) is wrapped around (or connected to) the pin  120   f  and extends down through the spring  120   c . A hole  120   u  houses a set screw  120   w  to secure the base  114   s  to support  120   h.    
     In certain particular aspects, two first coils  120   j  of the spring  120   c , optionally of high elasticity material allow the poppet  114   b  to center itself on a seat. After seating of the poppet  114   b  against a seat, the coils  120   j  are completely compressed and in contact. The remaining coils of the spring  120   c  take the load and thus elastically support the poppet  114   b.    
     The support  120   h  (see, e.g.,  FIGS. 12A-12C ) has a base  120   m  with two holes  120   z  for the spring projections  120   k.    
     The present invention, therefore, provides in at least some embodiments, a system for pumping a drilling fluid mixture, the drilling fluid mixture containing drilling fluid and solids, the system including: a pump apparatus; the pumping apparatus having a body with an inlet and an outlet; a suction valve in the body for selectively controlling flow of the drilling fluid mixture in through the inlet; a discharge valve in the body for selectively controlling flow of the drilling fluid mixture out through the outlet; each of the suction valve and the discharge valve having a seat with a curved valve seat surface and a valve member with a curved member surface, part of the valve member movable to seat the curved member surface against the curved valve seat surface to prevent the flow of the drilling fluid mixture past the valve seat. Such a system according to the present invention may have one or some (in any possible combination) of the following: a seal recess in the curved valve seat of each of the suction valve and the discharge valve, a seal positioned in each seal recess so that resonating of the seal is inhibited, each valve member movable to seat against a corresponding seal; wherein each valve member has a range of freedom of movement for effecting seating against an adjacent corresponding curved valve seat surface (and, in certain aspects, against a seal in the valve seat), the freedom of movement including the ability to move not just toward and away from the valve seat but at an angle thereto; wherein each valve member has a spring urging the valve member against the curved valve seat surface; wherein the spring has a spring body with a first end and a second end, the first end in contact with the valve member, the first end tapering from the spring body; each valve having a cartridge stem positioned with respect to the valve member, and a valve actuator within the cartridge stem for selectively moving the valve member; wherein the valve actuator is interconnected with the valve member via a cable; the valve actuator includes a selectively expandable hose for moving the valve member; an air supply for supplying air to the valve actuator, and a control system for controlling the air supply to selectively open and close the valve; a ball movably mounted within each valve member, the cable connected to the ball and to the valve actuator, the valve member movable with respect to the ball; each valve member has a rounded nose and a curved tapered outer surface so that fluid flow contacting the nose and curved tapered outer surface forms stabilizing fluid cushions around the valve member; each valve member has a back surface, a portion of the fluid flow onto the nose and curved outer surface gradually changes direction on the back surface; wherein the seat has a flow channel adjacent the curved valve seat and the valve member is movable to close off flow through the flow channel and wherein the flow channel is unobstructed; and/or wherein each valve member has a spring urging the valve member against the curved valve seat surface, each spring having a top end with at least one curved spring projection, a spring mount within the valve member, the at least one spring projection movably connected to the spring mount to facilitate freedom of movement of the valve member with respect to the curved valve seat surface and/or a dampener within the body for inhibiting pulsations of fluid pumped from the pump apparatus. 
     The present invention provides systems for pumping a drilling fluid mixture, the drilling fluid mixture containing drilling fluid and solids, the systems having: a pump apparatus, the pumping apparatus having a body with an inlet and an outlet, a suction valve in the body for selectively controlling flow of the drilling fluid mixture in through the inlet, a discharge valve in the body for selectively controlling flow of the drilling fluid mixture out through the outlet, each of the suction valve and the discharge valve having a seat with a curved valve seat surface and a valve member with a curved member surface, part of the valve member movable to seat the curved member surface against the curved valve seat surface to prevent the flow of the drilling fluid mixture past the valve seat, a seal recess in the curved valve seat surface of each of the suction valve and the discharge valve, a seal positioned in each seal recess so that resonating of the seal is inhibited, each valve member movable to seat against a corresponding seal, each valve having a cartridge stem positioned with respect to the valve member, and a valve actuator within the cartridge stem for selectively moving the valve member. 
     The present invention provides a method for pumping fluid, the method including: sucking fluid into an inlet of a pumping apparatus of a system, the system comprising a pump apparatus, the pumping apparatus having a body with an inlet and an outlet, a suction valve in the body for selectively controlling flow of the drilling fluid mixture in through the inlet, a discharge valve in the body for selectively controlling flow of the drilling fluid mixture out through the outlet, each of the suction valve and the discharge valve having a curved valve seat surface and a valve member with a curved member surface, part of the valve member movable to seat the curved member surface against the curved valve seat surface to prevent the flow of the drilling fluid mixture past the valve seat; and with the pump apparatus, pumping fluid into the inlet and then out the outlet. The present invention provides wherein such a system, in certain aspects, that has a seal recess in the curved valve seat of each of the suction valve and the discharge valve, a seal positioned in each seal recess so that resonating of the seal is inhibited, each valve member movable to seat against a corresponding seal, the method further including seating each valve member surface against a corresponding seal; and/or wherein each valve has a cartridge stem positioned with respect to the valve member, and each valve has a valve actuator within the cartridge stem for selectively moving the valve member, the method further including actuating each of the suction valve and the discharge valve with the valve actuator. 
     The present invention provides a method for pumping fluid, the method including: sucking fluid into an inlet of a pumping apparatus of a system, the system having a pump apparatus, the pumping apparatus having a body with an inlet and an outlet, a suction valve in the body for selectively controlling flow of the drilling fluid mixture in through the inlet, a discharge valve in the body for selectively controlling flow of the drilling fluid mixture out through the outlet, each of the suction valve and the discharge valve having a curved valve seat surface and a valve member with a curved member surface, part of the valve member movable to seat the curved member surface against the curved valve seat surface to prevent the flow of the drilling fluid mixture past the valve seat, wherein each valve member has a range of freedom of movement for effecting seating against an adjacent corresponding curved valve seat surface; with the pump apparatus, pumping fluid into the inlet and then out the outlet; controlling fluid flow in through the inlet with the suction valve; and controlling fluid flow out the outlet with the discharge valve. 
     The present invention provides a method for pumping fluid, the method including: sucking fluid into an inlet of a pumping apparatus of a system, the system including a pump apparatus, the pumping apparatus having a body with an inlet and an outlet, a suction valve in the body for selectively controlling flow of the drilling fluid mixture in through the inlet, a discharge valve in the body for selectively controlling flow of the drilling fluid mixture out through the outlet, each of the suction valve and the discharge valve having a curved valve seat surface and a valve member with a curved member surface, part of the valve member movable to seat the curved member surface against the curved valve seat surface to prevent the flow of the drilling fluid mixture past the valve seat, each valve having a cartridge stem positioned with respect to the valve member, and a valve actuator within the cartridge stem for selectively moving the valve member; with the pump apparatus, pumping fluid into the inlet and then out the outlet; and with the valve actuator selectively operating the suction valve and the discharge valve. 
     The present invention provides a valve for a valve assembly for a pump apparatus of a system for pumping a drilling fluid mixture, the drilling fluid mixture containing drilling fluid and solids, the pumping apparatus having a body with an inlet and an outlet, the valve for disposition in one of the inlet and outlet for selectively controlling flow of the drilling fluid mixture, the valve including: a seat with a curved valve seat surface, a valve member with a curved member surface, part of the valve member movable to seat the curved member surface against the curved valve seat surface to prevent the flow of the drilling fluid mixture past the valve seat. Such a valve may have a seal recess in the curved valve seat surface, a seal positioned in the seal recess, the valve member movable to seat against the seal. 
     The present invention provides a valve for a system for pumping a drilling fluid mixture, the drilling fluid mixture containing drilling fluid and solids, the valve having: a seat with a valve seat surface, a valve member with a member surface, part of the valve member movable to seat the member surface against the valve seat surface to prevent the flow of the drilling fluid mixture past the valve seat, a cartridge stem positioned with respect to the valve member, and a valve actuator within the cartridge stem for selectively moving the valve member. 
     The present invention provides system for pumping a drilling fluid mixture, the drilling fluid mixture containing drilling fluid and solids, the system having: a pump apparatus, the pumping apparatus having a body with an inlet and an outlet, a suction valve in the body for selectively controlling flow of the drilling fluid mixture in through the inlet, a discharge valve in the body for selectively controlling flow of the drilling fluid mixture out through the outlet, and a dampener within the body for inhibiting pulsations of fluid pumped from the pump apparatus. 
       FIGS. 13A, 13B, 13C  show a mud pump module  780  according to the present invention with a suction valve assembly  782 , a pumping chamber  784 , a suction inlet  786 , a discharge valve assembly  788  and a discharge outlet  792 . A connection  787  connects the module  780  to a pumping cylinder. The valve assemblies are in a module block  794  shown schematically in  FIGS. 13A and 13B  as the 
     outer boundary line around the valve assemblies and a dampener system  700 . 
     Dampener systems inhibit or prevent (“dampen”) undesirable fluid pulsations. Discharge valve assemblies, surrounding parts, downstream pipe lines, line supports, mud motors, pressure signals, and other parts can be subjected to damaging fluid pulsations. The pumping mechanism typically has a crank and one or more pistons and corresponding push rods. Regardless of the actual number of pistons, the mechanism&#39;s motion obeys the dynamics law of a single piston and crank mechanism in which the piston&#39;s velocity and acceleration have a sinusoidal variation over the length of a stroke. These two parameters will vary in opposite phase relative to each other, but they have a gradual variation over time. The fluid that enters or leaves the pumping chamber will try to follow these gradual variations. However, friction, inertia and turbulence or resistances to flow oppose to this gradual movement. As the operating speed or the rotating speed of the crank is increased, the opposing forces will increase too. As a critical speed is reached, the opposing/resisting forces are high enough to slow down the fluid so that it can not maintain contact with the piston&#39;s surface. Thus, a void is formed in the column of fluid. Cavitation or fluid boiling takes place if the pressure in the fluid column is not higher than the vapor pressure. The piston&#39;s velocity is zero at either end of the stroke with a maximum at midstroke. Acceleration on the other hand, is maximum at the ends with a minimum at piston&#39;s midstroke. Thus, during a stroke, the piston will accelerate and decelerate a block or volume of fluid. Simultaneously, inertia and fluid flow resistances will increase and decrease in a slight asynchronism with velocity. Thus, the fluid is still accelerating as the piston slows down past its midstroke. Consequently, the fluid continues rushing into the pumping cylinder because of inertia as the piston slows down past its midstroke. Suddenly, the column of fluid comes to an abrupt stop as it hits the piston and its movement slows down even further because it approaches its stroke end. This process results into a sudden pressure rise or spike. The rate at which the pressure spike rises or decreases is generated by factors like pipe sizing, number and shape of fittings along the pipe, the mud&#39;s nature, weight and temperature, as well as the valve&#39;s flow capacity and the friction between the fluid and surrounding walls and bodies. 
     The suction valve assembly  782  sucks fluid (drilling mud) through the suction inlet  786  into the pumping chamber  784 . Upon discharging of this fluid from the pumping chamber  784  by the action of the discharge valve assembly  788 , the discharge valve assembly and parts thereof can be subjected to damaging fluid pulsations. The dampener system  700  reduces or eliminates the damaging effects of these pulsations. In effect, a dampener system provides an expansion volume where fluid can rush in during a pressure spike, or an extra source of fluid in addition to the main source. This makes possible a more uniform volume flow through the block with mud surges suppressed or eliminated. The dampener system also stores energy that is returned into the system during a depression or negative pressure variation inside the valve block or downstream pipe string. 
       FIG. 13C  shows the dampener system  700  and  FIGS. 13D-13M  show various parts of the system  700 . As described in detail below, as shown in  FIG. 13C  (and  FIGS. 13D-13H ) the dampener system  700  is under pressure; as shown in  FIG. 13I  the system is under no pressure; and as shown in  FIGS. 13J-13M , the system is under partial pressure. 
     The dampener system  700  has a housing  702  (or “bottle”) which houses a liner  710 . A valve assembly  704  (proportional valve) is in fluid communication with the interior of the bottle  702  via a connection  706 . In one aspect the valve assembly  704  is a proportional valve assembly selectively controllable by a control system  708  (exterior to the block  794 ). The valve assembly  704  selectively controls flow through a line  722  to a piston-cylinder apparatus  720  which includes a torsion apparatus  730 . 
     The bottle  702  is in fluid communication with the pumping chamber  784  via a line  712 , a connection  714 , and a line  716 . 
     As shown, e.g., in  FIGS. 13C, 13J and 13K , the piston-cylinder apparatus  720  has a housing  721  into which and from which fluid flows via the line  722  to move a piston  723 . An end  724  of the piston  723  projects out from the housing  721  and is pivotably connected to the torsion apparatus  730 . The housing  721  is connected to a support  725  and the piston  723  moves in a base  726  of the support  725 . Seals  727  seal piston-base interfaces. 
     As shown, e.g., in  FIG. 13M , the torsion apparatus  730  has an arm  731  rigidly connected to a metal ring  732 . The metal ring  732  encloses outer rubber elements  734  (made, e.g. of rubber or any suitable flexible material); outer stops  735 ; inner metal stops  736 ; and inner rubber elements  737 . A central shaft  738  with shaft stops  739  is fixed to a bracket  730   b . When the piston  723  moves the body  731 , the body  731  rotates on the shaft  738  and the various rubber elements deform against the various stops. The shaft  738  is secured to brackets  730   b  with nuts  730   c  and the brackets  730   b  are secured to the housing  702 . As hydraulic fluid under pressure is expelled from the bottle  702 , through the proportional valve  704  and the line  722  into the housing  720 , it pushes down on the piston  723 , and through an end  724  of the piston it acts on the arm  731 . In turn, the arm  731  rotates the metal ring  732  about the axis of the fixed shaft  738 . Since stops  735  are welded/rigidly attached to the metal ring  732 , and as the metal ring  732  is rotating, the outer rubber elements  734  are compressed between the stops  735  and the inner metal stops  736 . As a result, the inner metal stops  736  rotate in the same direction of rotation with the outer metal ring  732 . Consequently, the inner rubber elements  737  are compressed between the ring of inner metal stops and the fixed shaft stops  739  that are welded/rigidly attached to the fixed shaft  738 . The rubber elements  734  and  737  are compressed until, relative to the metal ring  732 , they develop a moment equal with the one developed by the pressure acting on the end  724  that acts on the arm  731  respectively. 
       FIGS. 14A-14C  show the bottle  702 . Recesses  703  around the surface of the bottle  702  hold hydraulic fluid or oil which can flow via a recess  705  to and out from (and into) the connection  706 . The circumferential recesses  703  enhance fluid flow from around the liner into the main connection  706  and finally into the housing  720 . An expanded liner under pressure would block or restrict fluid flow if the interior surface would be smooth without these circumferential recesses. This would occur because under higher pressure the liner would expand until its ridges would come into full contact with the housing. Thus, the fluid between the liner&#39;s two adjacent lobes/recesses would not be expelled into the main recess  705  and further down into the proportional valve and finally into the housing  720 . Consequently, the dampener&#39;s function would be negatively affected because it would not be able to expel the required amount of hydraulic fluid and at the required rate in order to accommodate the mud&#39;s instantaneous pressure variations. It is the hydraulic fluid or oil pushed from the bottle  702  that acts on the piston  723 . 
       FIGS. 15A-15E  show the liner  710  which has a body  711  with recesses  712 . Outer flanges  715  are mounted in the housing  702  as shown, e.g., in  FIG. 13C . The inner surface  716  of the liner  710  has, optionally, a lobed or corrugated shape which increases the elasticity of the liner  710  and, therefore, facilitates quick response to pressure pulsations and enhances the life of the liner  710  by limiting stretching of the liner  710 . 
       FIGS. 16A-16D  illustrate the dampener system  700  under pressure (i.e., subjected to the pressure of fluid in the pumping chamber  784 ). This pressure has expanded the liner  710 , pushing fluid to the valve assembly  704 , and through the valve assembly  704  to the piston-cylinder apparatus  720  moving the piston  723  which, in turn, has rotated the arm  731  of the torsion apparatus  730  on the shaft  738  deforming some of the rubber elements of the torsion apparatus  730 . 
       FIGS. 16E and 16F  show the dampener system  700  under no pressure, with the rubber elements of the torsion apparatus  730  in a non-deformed shape. 
       FIGS. 17A and 17B  illustrate one embodiment of the valve assembly  704  which is a commercially-available controllable proportional valve assembly, e.g., but not limited to, a commercially-available models from Sun Company. 
       FIGS. 18A-18D  show a mud pump module  802  according to the present invention in a block  804  (shown schematically to include valve assemblies  806 ,  808 ; a pumping chamber  805 ; a suction inlet  807 ; a discharge outlet  809 ; and a dampener system  810  according to the present invention). 
     The dampener system  810  is shown in  FIGS. 19A-19E . Via a line  812  a bladder  820  of the dampener system  810  is in fluid (drilling mud) communication with the pumping chamber  805 . The system  810  has a housing  814  with a top cover  816 ; an intermediate cover  818 ; the bladder  820  a spring  822 ; a valve assembly  830 ; and a ring  824 . 
     Via a line  826   a  and a check valve  826  the interior of the housing  814  is in fluid communication with an hydraulic fluid source  834  (see  FIG. 19A ) (shown schematically). Via a line  828 , the interior of the housing  814  is in fluid communication with the valve assembly  830 . Via a line  829   a  and a check valve  829 , the valve assembly  830  is in fluid communication with a reservoir RV of hydraulic fluid under atmospheric pressure and the hydraulic power source draws fluid from the reservoir. The valve assembly  830  is, in certain aspects, like any embodiment of the valve assembly  704  ( FIG. 13A ) and can be controlled by a control system  832  (shown in  FIG. 19A ; like the control system  708 ,  FIG. 13C ). 
     The pressure of the mud in the bladder is the pressure of mud in the pumping chamber  805 . This pressure is continuously measured using a pressure transducer  836  in the block  804 . The pressure transducer  836  is in communication with a control module  838  (e.g. the control system  832 ,  FIG. 19A ). The drilling&#39;s mud pressure is continuously monitored through the pressure transducer  836  and this pressure [value expressed in e.g., in a scaled voltage (V volts) or milliamperes (ma) per psi or other appropriate unit of pressure measurement] is entered into the control module  838 . The control module&#39;s output is a PWM (Pulse Width Modulated) signal that, in turn, controls the valve assembly  830 . This PWM signal is inversely proportional to the mud&#39;s pressure. Thus, as the pressure increases, the control module  838  sends a lower signal. Conversely, as the pressure decreases, the control module  838  sends a higher signal. Additionally, the valve assembly  830  is normally closed, meaning that no fluid flows through it when it is not powered. In other words, the proportional valve partially opens when a lower signal (or current) is applied and it fully opens when a higher current (or signal) (PWM signal) is applied. Consequently, when a very high pressure is sensed inside the valve block  804 , the control module  838  sends a low level PWM signal to the valve assembly  830  and the valve will not open at all or it opens only a minute amount. The amount that the valve will open at this stage depends on a pre-established threshold. By slightly releasing the pressure on the oil side, the rubber bladder  820  will be able to deform and, thus, accommodate an instantaneous pressure variation on the mud side. As the pressure on the mud side decreases, the control module  830  sends a high signal that opens the valve even further. However, when the pressure wave is on the reverse side and increases inside the valve block  804 , the control module  838  sends a lower signal and the process continues. By controlling the threshold at which the valve opens/reacts, the operator can filter out certain frequencies (frequency of pulsation of fluid) providing, in effect, the equivalent of a continuously adjustable high band filter. As the threshold is increased, or the valve reacts at a higher and higher signal, the low end of the filtering band increases too. The frequencies that are below the pressure threshold (pressure that generates the minimum signal at which the valve reacts) will pass unobstructed through the valve block  804  and further down along the discharge line. The filtered frequency band is narrow in this case. However, as the pressure threshold is lowered, even lower pressures will force the control module  838  to send a signal at which the valve assembly  830  reacts. Consequently, lower and lower frequencies are attenuated and less damaging energy is propagated along the discharge line past the discharge outlet  809 , and to the discharge valve assembly  808 . 
     As shown in  FIGS. 20A-20C  the top cover  816  has a channel  812   a  for fluid communication with the line  812 . The top cover  816  has a recess  817  for accommodating a top flange  821  of the bladder  820  as described below. 
     As shown in  FIGS. 21A-21C , the intermediate cover  818  has a projection  811  with an opening  819  through which passes a neck  823  of the bladder  820 . Optionally, the two covers are made as a single integral piece. The bladder  820  has a bottom  844  and a lobed body  840  with a plurality of spaced-apart lobes  842 . This construction yields a structure which is under no stress at any time, even under the slightest or largest excitation. Stress in a material occurs only when the material is stretched. In other words, there is no more material to move along in the direction of deflection. For example, consider a piece of rubber band placed atop a table and one end of this piece is fixed through any method, i.e. in between the fingers of one hand. At the other end a force is applied in, e.g., a longitudinal direction. The rubber band will start stretching and this will be evident because there is no extra material to compensate for the displacement of the taught end. Now assume that the rubber band is placed between a person&#39;s hands. The distance between the hands is so that the rubber droops. Moving one hand straightens the rubber. No stress is applied so far because there is enough material to compensate for the displacement. The rubber will start stretching only after it becomes perfectly straight and there is no more material to compensate for the displacement. The lobes  842  play the role of the “droops” as discussed above. Thus, the lobes  842  secure enough material allowing the bladder to balloon or increase its form without stretching or stressing the rubber material Additionally, the lobes  842  are sized so that their circumference and, thus, the bladder&#39;s total circumferential length in relaxed condition, is greater than the total circumferential length in expanded condition. Moreover, when the bladder is expanded, it can reach only a maximum size/diameter. This size is determined/limited by the inside diameter of the housing. Under fully expanded condition, the bladder is in full contact with the housing. Consequently, even with the interior pressure increasing, the bladder can not expand any more because it is fully and rigidly supported by the housing&#39;s walls. 
     The envelope or size of the bladder increases in form only, and not due to stress, since there is sufficient bladder material to compensate for an increase in pressure and consequently, an increase in size until the bladder comes in full contact with surrounding walls. The rubber or flexible material of the bladder is not stretched and the bladder is supported at the top by the intermediate cover  818  and the flange  821  resting thereon and at the bottom by a curved base  846  of the housing  814 . A non-stressed bladder, all things being equal, outlasts a stressed bladder. 
       FIGS. 23A-23E  illustrate the housing  814  which includes a flange  848  and a lower channel  852  which is in fluid communication with the line  828 . 
     As shown, e.g., in  FIG. 23D , a curved surface  854  of the curved base  846  corresponds to a lower curved part  856  of the bladder  820 . As shown in  FIG. 23E  a curved edge  858  of the intermediate cover  818  corresponds in shape to a surface  860  of the bladder  820 . 
       FIGS. 24A-24D  show the spring  822  in the form of a wave-shaped spring with a body  862  with multiple spaced-apart ridges  864  and valleys  866 .  FIGS. 24A and 24B  show the spring  822  in an unpressurized mode and  FIGS. 24C and 24D  show the system under pressure. In one aspect, the number of the ridges  864  and of the valleys  866  is higher than the bladder&#39;s number of lobes. Thus a bladder&#39;s lobe is supported by two or more ridges on the spring  822 . This insures the lobes and, therefore, the bladder, are supported and the two do not simply “mesh” one into the other. 
       FIGS. 25A-25D  show the ring  824  which has a body  868  with ends  867 ,  869 . The ring  824  provides a protective barrier between the bladder  820  and the spring  822  and it expands and contracts in response to pressure. This structure reduces friction between the rubber/bladder  820  and wave-shaped spring  822 . Thus, the bladder  820 , during its expansion under pressure, slides relative to the spring  822 . Consequently, no material is stretched even in a very thin outside layer. This also contributes to the life span of the lobed bladder. Uncontrolled stretching and movement are reduced.  FIGS. 25A and 25B  show the ring  824  in a non-pressurized state.  FIGS. 25C and 25D  show the ring  824  under pressure folded on itself with the ends  867 ,  869  unconnected and can expand and contract without restriction. 
       FIGS. 26A-26C  illustrate the bladder  820  under pressure, i.e., with drilling mud therein under pressure from a block&#39;s pumping chamber. As shown in  FIGS. 26A and 26C , the bladder  820  has expanded and the lower part  856  of bladder  820  has moved and is supported by the curved surface  854  of the curved base  846 . 
     In  FIGS. 23D and 23E , the device is under no pressure, the spring  822  is contracted forcing the bladder to its smallest dimension. Thus, there is space between the housing and the spring. The spring is away from and spaced-apart from the housing&#39;s surrounding wall. As shown in  FIG. 26B , the bladder is fully expanded and forces the spring to come in contact with the housing&#39;s wall. Since the spring is pushed against the wall, the spring&#39;s waves are compressed and reduced until the spring can not be compressed any more. There is no space between the spring and the wall in this picture. Additionally, the spring&#39;s width is relatively reduced. 
     As shown in  FIGS. 26D and 26E , the pressure of the mud in the bladder  820  has pushed out the ridges  864 . 
     The bladder  820  provides a separating membrane between two media (the mud being pumped and the hydraulic fluid or oil supplied from the source  834 ). A pulsation/pressure variation in the mud column translates into the bladder&#39;s ballooning or shrinkage. The bladder balloons if the pressure inside it increases past the resistive force offered by the sum of the “returning mechanism” plus the resistive force generated by the oil flowing through a controlled valve orifice (e.g. of the valve assembly  830 ; or of the valve assembly  704  described above). The “returning mechanism” includes the surrounding spring  822  (or, optionally, a piston powered by a spring or a constant pressure hydraulic power source and a check valve). If the valve orifice is fully blocked, and because generally speaking a fluid is incompressible, the oil can not escape from in between the bladder and the surrounding housing. In the case of a hydraulic source  834  and check valve  829  this is possible because a higher pressure inside the dampener housing will shut close the check valve  829 . This results in a relatively rigid bladder that will not be able to accommodate any pressure increase on the mud&#39;s side. Consequently, a pressure wave in the mud&#39;s column will pass undisturbed down further into the discharge pipe line. Conversely, the bladder shrinks when the pressure inside it, pressure that equals the mud column pressure, becomes smaller than the sum of the surrounding spring&#39;s force (spring  822 ) and of the fluid&#39;s/oil&#39;s flow back into the reservoir RV. In the instance of a constant pressure hydraulic source  834  used as return mechanism, the check valve  826  stays open because the pressure inside the bladder is smaller than that of the hydraulic source  834 . The fluid from the hydraulic source  834  flows into and through the space in between the bladder and housing as long as the proportional valve  830  allows it. If the proportional valve  830  is fully closed than the check valve  826  stays open until the entrapped fluid assumes the pressure of the hydraulic source  834 . As soon as this moment is reached, any minute pressure increase on the mud side forces an increase in pressure on the hydraulic or oil side and the check valve  826  shuts off. In turn, this results in no back flow condition from the dampener system back to the hydraulic source  834 . On the other hand, this translates into an increase in pressure that is recorded by the pressure transducer  836  and it forces a signal from the control unit. This signal opens the valve orifice of the proportional valve  830  even a minute amount but enough to release oil back to the reservoir RV. Consequently, the pressure drops at a prescribed rate. As a result, the mud&#39;s pressure might become slightly larger and mud will enter into the bladder. This rush of mud into the bladder is converted into a pressure drop inside the pumping chamber  805  and, thus, into a controlled pressure at the outlet  809  and along the discharge line. The hydraulic source  834  plays the role of a “returning mechanism” and not of a controlling one. In one aspect, in this design, the hydraulic source&#39;s pressure can be sufficiently low to just push back the bladder to its relaxed shape. The bladder as a separating membrane stays in full contact with the pressure varying mud. The “returning mechanism” (a spring, gas, or oil under some pressure) acts as an elastic element that pushes back the bladder in its full contact with the pulsating mud. The controlling mechanism includes intentionally and controllably bleeding fluid through a controlled valve e.g. the valve  830  from the dampener&#39;s oil side into the reservoir RV in order to accommodate and compensate for pressure pulsations/variations on the mud side, resulting in a close to constant pressure at the outlet  809  in the pump&#39;s discharge line. 
     Each of the systems described above can provide control of a valve assembly (e.g., but not limited to, a proportional valve assembly) which permits the valve assembly to be adjusted in response to pressure changes so that the dampener system adjusts to pulsations of varying frequency. In one aspect, the control system does this in real time, on-the-fly. In one aspect, the control system controls the valve assembly (to control the piston-cylinder apparatus) so that the dampener system adjusts for pulsation frequencies from 2 to 6000 Hertz; and, in other aspects, for pulsations with frequencies between 1 to 4000 Hertz or between 1 to 1000 Hertz. 
     Instead of the particular dampeners and dampener elements described above, it is within the scope of the present invention to use a known dampener, e.g., but not limited to, a coiled spring or a fluid reservoir dampener apparatus, which can return a piston to a relaxed position or past such a position when there is vacuum inside a valve block. Under a condition of vacuum/depression, the piston pumps fluid inside the valve chamber and, thus, maintain as close as possible a constant preset pressure. 
     The present invention, therefore, provides in some, but not in necessarily all embodiments a system for pumping a drilling fluid mixture, the drilling fluid mixture containing drilling fluid and solids, the system including: a pump apparatus; the pumping apparatus having a body with a pumping chamber, an inlet and an outlet; a suction valve in the body for selectively controlling flow of the drilling fluid mixture in through the inlet; a discharge valve in the body for selectively controlling flow of the drilling fluid mixture out through the outlet; each of the suction valve and the discharge valve having a seat with a curved valve seat surface and a valve member with a curved member surface, part of the valve member movable to seat the curved member surface against the curved valve seat surface to prevent the flow of the drilling fluid mixture past the valve seat; and a dampener system (any disclosed herein according to the present invention) in fluid communication with the pumping chamber. 
     The present invention, therefore, provides in some, but not in necessarily all embodiments a system for pumping fluid, the system including: a pump apparatus; the pumping apparatus having a body with a pumping chamber, an inlet and an outlet; a suction valve in the body for selectively controlling flow of the fluid in through the inlet; a discharge valve in the body for selectively controlling flow of the fluid out through the outlet; a dampener system in fluid communication with the pumping chamber; the dampener system having a base, a housing connected to the base, the housing having an interior, a liner within the housing, the liner expandable in response to fluid pressure, a piston/cylinder apparatus in fluid communication with the housing, the piston/cylinder apparatus having a movable piston movable in response to fluid flowing from the housing to the piston/cylinder apparatus, a torsion apparatus movably connected to the base, the piston movable to contact and to move the torsion apparatus in response to fluid flowing from the housing to the piston/cylinder apparatus, and the torsion apparatus movable by the piston from a first static position to a second position to dampen pulsations of fluid into the pumping chamber. 
     The present invention, therefore, provides in some, but not in necessarily all embodiments a system for pumping a fluid, the system including: a pump apparatus, the pumping apparatus having a body with a pumping chamber, an inlet and an outlet, a suction valve in the body for selectively controlling flow of the fluid in through the inlet, a discharge valve in the body for selectively controlling flow of the fluid out through the outlet, a dampener system in fluid communication with the pumping chamber, a housing, the housing having an interior, a deformable bladder within the housing, the deformable bladder in fluid communication with the pumping chamber, and the deformable bladder deformable in response to pressure variation in the pumping chamber. 
     The present invention, therefore, provides in some, but not in necessarily all embodiments a dampener system including: a base, a housing connected to the base, the housing having an interior, a liner within the housing, the liner expandable in response to fluid pressure, a piston/cylinder apparatus in fluid communication with the housing, the piston/cylinder apparatus having a movable piston movable in response to fluid flowing from the housing to the piston/cylinder apparatus, a torsion apparatus movably connected to the base, the piston movable to contact and to move the torsion apparatus in response to fluid flowing from the housing to the piston/cylinder apparatus, and the torsion apparatus movable by the piston from a first static position to a second position to dampen pulsations of fluid in the housing. 
     The present invention, therefore, provides in some, but not in necessarily all embodiments a dampener system including: a housing, the housing having an interior, a deformable bladder within the housing, the deformable bladder in fluid communication with the pumping chamber, the deformable bladder deformable in response to pressure variation in the pumping chamber, a valve assembly in fluid communication with a fluid reservoir and in fluid communication with the interior of the housing, a control system for controlling the valve assembly, the valve assembly controllable to control deformation of the deformable bladder, the deformable bladder having a bladder body with a top, a bottom, and a side wall, and the side wall comprising a lobed wall with a plurality of spaced-apart lobes therearound to inhibit stress on the bladder body. 
     The present invention, therefore, provides in some, but not in necessarily all embodiments methods for dampening a pumped fluid (e.g. a pumped drilling fluid mixture), the fluid pumped by a system having a pump apparatus; the pumping apparatus having a body with a pumping chamber, an inlet and an outlet; a suction valve in the body for selectively controlling flow of the fluid in through the inlet; a discharge valve in the body for selectively controlling flow of the fluid out through the outlet; and a dampener system (any according to the present invention) in fluid communication with the pumping chamber; the method including pumping the drilling fluid mixture with the pump apparatus, and dampening the pumped drilling fluid with the dampener system. 
     In conclusion, therefore, it is seen that the present invention and the embodiments disclosed herein and those covered by the appended claims are well adapted to carry out the objectives and obtain the ends set forth. Certain changes can be made in the subject matter without departing from the spirit and the scope of this invention. It is realized that changes are possible within the scope of this invention and it is further intended that each element or step recited in any of the following claims is to be understood as referring to the step literally and/or to all equivalent elements or steps. The following claims are intended to cover the invention as broadly as legally possible in whatever form it may be utilized. The invention claimed herein is new and novel in accordance with 35 U.S.C. §102 and satisfies the conditions for patentability in §102. The invention claimed herein is not obvious in accordance with 35 U.S.C. §103 and satisfies the conditions for patentability in §103. This specification and the claims that follow are in accordance with the requirements of 35 U.S.C. §112. The inventors may rely on the Doctrine of Equivalents to determine and assess the scope of their invention and of the claims that follow as they may pertain to apparatus and/or methods not materially departing from, but outside of, the literal scope of the invention as set forth in the following claims. All patents and applications identified herein are incorporated fully herein for all purposes. It is the express intention of the applicant not to invoke 35 U.S.C. §112, paragraph 6 for any limitations of any of the claims herein, except for those in which the claim expressly uses the words ‘means for’ together with an associated function. In this patent document, the word “comprising” is used in its non-limiting sense to mean that items following the word are included, but items not specifically mentioned are not excluded. A reference to an element by the indefinite article “a” does not exclude the possibility that more than one of the element is present, unless the context clearly requires that there be one and only one of the elements. 
     Whereas the present invention has been described in particular relation to the drawings attached hereto, it should be understood that other and further modifications apart from those shown or suggested herein, may be made within the scope and spirit of the present invention.