Abstract:
A knife gate valve for specific environments comprises a knife valve with a body, a hand wheel, a yoke sleeve, a gland packing, a gland bushing, a stem, a wedge gate, seating surfaces and the like. All internal components of the device are provided with a high quality elastomeric liner. This surface is present on wetted surfaces such as body, seat and wedge surfaces exposed to the controlled material. This feature provides corrosion resistance, long life, and reduces leakage when compared to conventional valves. Its new style of internal design provides waterproof resistance for virtually types of industrial applications.

Description:
RELATED APPLICATIONS 
     The present invention was first described in a notarized Official Record of Invention on Jul. 31, 2009, that is on file at the offices of Montgomery Patent and Design, LLC, the entire disclosures of which are incorporated herein by reference. 
     FIELD OF THE INVENTION 
     The present invention relates generally to knife-style gate valves, and in particular, to a knife-style gate valve including an elastomeric liner construction particularly suited for use on wet scrubbers to control liquid slurry flow. 
     BACKGROUND OF THE INVENTION 
     Gate valves, also known as knife valves or slide valves, are a common item in industrial plants around the world. They are used in pipelines to control the flow of material through them. Their design ensures that pressure drops across an open valve are kept to a minimum. They are particularly useful when used with slurries or high viscosity liquids such as heavy oils, grease, or thick food products. However, their design also causes accelerated corrosion and erosion of seat and wedge surfaces due to their exposure. Over time, this erosion and corrosion will lead to failure of the valve requiring replacement which is not only costly from a time and labor standpoint, but from lost production from the associated industrial process as well. One (1) approach has been to attempt to construct gate valves with liners to combat these disadvantages. 
     Various attempts have been made to provide gate valves with liners for industrial use. Examples of these attempts can be seen by reference to several U.S. patents including U.S. Pat. No. 2,893,684; U.S. Pat. No. 3,993,092; U.S. Pat. No. 4,009,727; U.S. Pat. No. 4,201,365; U.S. Pat. No. 7,100,893; and U.S. Pat. No. 7,350,766. 
     While these apparatuses fulfill their respective, particular objectives, each of these references suffer from one (1) or more disadvantages including an undesirably substantial number of mechanical connections and specialized tools or machinery required during manufacture, installation, operation, and repair; limitations in molding, manufacture, and assembly of various components, particularly liner constructions such as found in U.S. Pat. No. 3,993,092 and U.S. Pat. No. 7,100,893; and eventual leakage and failure due to fatigue on gate or liner portions of the apparatus. Accordingly, there exists a need for a knife-style gate valve and liner without the disadvantages as described above. The development of the present invention substantially departs from the conventional solutions and in doing so fulfills this need. 
     SUMMARY OF THE INVENTION 
     In view of the foregoing references, the inventor recognized the aforementioned inherent problems. Thus, the object of the present invention is to solve the aforementioned disadvantages and provide for this need. 
     To achieve the above objectives, it is an object of the present apparatus to comprise many of the same components as found in common gate valve manufacturing including a near body assembly and a distal body assembly providing a characteristic assembly that can be used in normal piping systems being connected in a conventional manner via four (4) system connection apertures to flanged portions of the piping system, formation from a standard material such as carbon steel or stainless steel, a yoke providing containment and control of various components, and a bonnet for mounting a hand wheel and a stem which enable actuation of the apparatus. The near and distal body assemblies comprise a plurality of viewing holes providing a means to identify an open or closed state of the gate. 
     Another object of the present invention is to form the gate, a wetted component of the apparatus, of a high quality stainless steel and to include a liner for which the particular material construction would vary based upon the specific application. It is envisioned that primary applications of the apparatus would be in application such as Flue Gas Desulfurization (FGD) and more specifically on use on wet scrubbers to control the flow of abrasive slurries. 
     Yet still another object of the present invention is to provide a design which can be widely applied to many industry fields, such as chemical plants, power plants, pulp and paper mills, and wastewater treatment plants, mining fields, sugar mills and food-processing facilities. In addition, the design of this knife gate valve can reduce the use of non-renewable natural resources, such as Hastelloy, and avoid the environmental pollution by heavy metals. 
     Yet still another object of the present invention is to mount the gate within a wiper which operates at a close tolerance. The wiper is formed from a high quality elastomeric urethane liner and allows the gate to operate in between a near body liner and distal body liner also formed from a high quality elastomeric urethane liner. In this manner the wiper, the near body liner, and the distal body liner are the only components of the apparatus that are wetted, or actually touch the liquid or liquid slurry that is controlled by the valve. 
     Yet still another object of the present invention is to provide enhanced corrosion resistance, reduced wear, longer life, and reduced leakage as compared to common gate valves due to the elastomeric nature of the aforementioned components and the gate. This construction is further envisioned to provide superior waterproofing and corrosion resistance. 
     Yet still another object of the present invention is to locate the gate inside of the wiper in a location where the gate can interrupt a flow of liquids or liquid slurry through the near body liner and distal body liner. 
     Yet still another object of the present invention is to hold the elastomeric components of the apparatus in place with a friction fit inside of the near body assembly and the distal body assembly with a plurality of connection bolts in lieu of mechanical fastening. The assembly process enables simple manual assembly of the apparatus without the need for complicated tooling such as presses, coatings or other aids. This assembly can also be reversed to aid in repair and replacement of the wetted components under field conditions, allowing for a fast return to service and reduced down time requiring only common hand tools. 
     Yet still another object of the present invention is to provide a method of utilizing the device including assembling a majority of the components used in the knife-style gate valve with elastomeric liner such as the near body assembly, the distal body assembly, the yoke, the bonnet, the hand wheel, the stem, and the connection bolts using conventional materials and following conventional manufacturing techniques; manufacturing the specialized components of the wiper, the near body liner and the distal body liner using elastomeric materials; assembling the aforementioned components in a manner that allows for fast manufacturing as well as fast repair using normal procedures; installing the valve within a piping system in a similar manner to a common gate valve; and using the valve to control abrasive fluids as previously described until replacement or repair is required. 
     Further objects and advantages of the present invention will become apparent from a consideration of the drawings and ensuing description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The advantages and features of the present disclosure will become better understood with reference to the following more detailed description and claims taken in conjunction with the accompanying drawings, in which like elements are identified with like symbols, and in which: 
         FIG. 1  is a front view of the knife-style gate valve with elastomeric liner  10  according to the preferred embodiment of the present invention; 
         FIG. 2  is a sectional view of the knife-style gate valve with elastomeric liner  10  as seen along a line I-I, as shown in  FIG. 1 , according to the preferred embodiment of the present invention; 
         FIG. 3   a  is a partially exploded view of the knife-style gate valve with elastomeric liner  10  according to the preferred embodiment of the present invention; 
         FIG. 3   b  is another partially exploded view of the knife-style gate valve with elastomeric liner  10  according to the preferred embodiment of the present invention; 
         FIG. 3   c  is still another partially exploded view of the knife-style gate valve with elastomeric liner  10  according to the preferred embodiment of the present invention; and, 
         FIG. 3   d  is yet another partially exploded view of the knife-style gate valve with elastomeric liner  10  according to the preferred embodiment of the present invention. 
     
    
    
     DESCRIPTIVE KEY 
     
         
         
           
               10  knife-style gate valve with elastomeric liner 
               15  gate valve assembly 
               20  near body assembly 
               25  distal body assembly 
               60  gate 
               30  first connection bolt 
               35  yoke 
               40  bonnet 
               45  hand wheel 
               50  stem 
               55  second connection bolts 
               57  viewing hole 
               58  system connection apertures 
               65  wiper 
               70  link pin 
               75  near body liner 
               80  distal body liner 
           
         
       
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The best mode for carrying out the disclosure is presented in terms of a preferred embodiment, herein depicted within  FIGS. 1 through 3   d . However, the disclosure is not limited to a single described embodiment and a person skilled in the art will appreciate that many other embodiments are possible without deviating from the basic concept of the disclosure and that any such work around will also fall under its scope. It is envisioned that other styles and configurations can be easily incorporated into the teachings of the present disclosure, and only one particular configuration may be shown and described for purposes of clarity and disclosure and not by way of limitation of scope. 
     The terms “a” and “an” herein do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced items. 
     Referring now to  FIG. 1 , a front view of the knife-style gate valve with elastomeric liner  10 , according to the preferred embodiment of the present invention, is disclosed. This figure demonstrates a gate valve assembly  15  comprised of many of the same components as found in the conventional teachings of gate valve manufacturing. A near body assembly  20  and a distal body assembly  25  (not visible in this figure) produce a characteristic assembly that can be used in normal piping systems being connected in a conventional manner via four (4) system connection apertures  58  to flanged portions of said piping system. The material of construction of the near body assembly  20  and distal body assembly  25  (not visible in this figure) is of standard material such as carbon steel, stainless steel, or the like. A yoke  35  is located above the gate valve assembly  15  and provides containment and control for remaining components of the knife-style gate valve with elastomeric liner  10 . It should be noted that the near body assembly  20  and the distal body assembly  25  are incorporated with the yoke  35  on each respective side. Differentiation is made as the purpose of each respective assembly and not to said construction. A bonnet  40  is provided atop the yoke  35  and provides a mounting surface for a hand wheel  45  and a stem  50 . When rotary motion is applied to the hand wheel  45  and subsequently transferred to the stem  50 , the knife-style gate valve with elastomeric liner  10  is actuated. The direction of the rotary motion determines whether the knife style gate valve with elastomeric liner  10  is opening or closing as would normally be expected. Additionally, the near body assembly  20  and the distal body assembly  25  comprise a plurality of viewing holes  57  providing a means to identify an open or closed state of the gate  60 . Viewing through an upper pair of viewing holes  57  in said body assemblies  20 ,  25  provides visibility of an upper edge of said gate  60  when in the open or raised state. In like manner, a lower pair of viewing holes  57  in each body assembly  20 ,  25  provides viewing of said upper edge of the gate  60  when said gate is in a closed or lowered state. Components are attached to the bonnet  40  and held captive by a set of four (4) second connection bolts  55  (only two (2) of which are visible in this orientation). Specialized components of the knife style gate valve with elastomeric liner  10  are primarily located inside of the near body assembly  20  and distal body assembly  25  (not visible in this figure) and will be described in greater detail herein below. 
     Referring next to  FIG. 2 , a sectional view of the knife-style gate valve with elastomeric liner  10 , as seen along a line I-I, as shown in  FIG. 1 , according to the preferred embodiment of the present invention is depicted. The near body assembly  20  and the distal body assembly  25  are held captive by four (4) first  30  connection bolts. The near body assembly  20  and the distal body assembly  25  would be made of conventional material such as cast iron. The hand wheel  45  and the stem  50  are likewise connected to the bonnet  40  by the second connection bolts  55  as aforementioned described. The stem  50  is connected to a gate  60  via a link pin  70 . The gate  60 , a wetted component of the knife-style gate valve with elastomeric liner  10  is made of a high quality stainless steel. The exact makeup of the liner would vary from application to application and would depend upon the specific application. It is envisioned that primary applications of the knife-style gate valve with elastomeric liner  10  would be in application such as Flue Gas Desulfurization (FGD) applications and more specifically on use on wet scrubbers to control the flow of abrasive slurries. It can also be widely applied to many industry fields, such as chemical plants, power plants, pulp and paper mills, and wastewater treatment plants, mining fields, sugar mills and food-processing facilities. In addition, the design of this knife gate valve can reduce the use of non-renewable natural resources, such as Hastelloy, and avoid the environmental pollution by heavy metals. The gate  60  is mounted within a wiper  65  which operates at a close tolerance. The wiper  65  is of a high quality elastomeric urethane liner. The wiper  65  allows the gate  60  to operate in between a near body liner  75  and a distal body liner  80 . Both the near body liner  75  and the distal body liner  80  are manufactured of high quality elastomeric urethane liner. It should be noted that the wiper  65 , the near body liner  75 , and the distal body liner  80  are the only components of the knife-style gate valve with elastomeric liner  10  that are wetted, or actually touch the liquid and/or liquid slurry that is controlled by the knife-style gate valve with elastomeric liner  10 . Similarly, the wiper  65 , the near body liner  75 , and the distal body liner  80  are the only components of the knife-style gate valve with elastomeric liner  10  that are made with the high quality elastomeric liner while the gate  60  is made of stainless steel. Such material may be solid in nature, or may surround a core made of more rigid material such as metal. The elastomeric nature of said components provides for enhanced corrosion resistance, reduced wear, longer life, and reduced leakage when compared to conventional valves. It will also provide better waterproof and corrosion resistant performance as well. 
     Referring now to  FIG. 3   a , a partially exploded view of the knife style gate valve with elastomeric liner  10  according to the preferred embodiment of the present invention is shown. This figure clearly shows the components of the knife style gate valve with elastomeric liner  10  that are made of elastomeric materials, namely the gate  60 , the wiper  65 , the near body liner  75  and the distal body liner  80  shown in a general position and relationship to one another. Note that the wiper  65  is separate from the gate  60 , but is simply shown together for the purposes of illustration. The gate  60  is inserted inside of the wiper  65 , and in a location where the gate  60  may interrupt flow of liquids and/or liquid slurry through the near body liner  75  and distal body liner  80 . It should be noted that these elastomeric components are not held in place via any direct mechanical or adhesive means attached to them directly. In lieu of such mechanical fastening, the gate  60 , the wiper  65 , and the near body liner  75  are held via a friction fit inside of the near body assembly  20  and the distal body assembly  25  via the first connection bolts  30  (as shown in  FIG. 1  and  FIG. 2 ). Additional descriptions herein below will further describe the assembly process. Said assembly process provides for easy hand assembly with the need for complicated tooling such as presses, coatings or other aids. Said assembly can also be reversed to aid in repair and replacement of the wetted components under field conditions allowing for a fast return to service and reduced down time using only common hand tools. 
     Referring next to  FIG. 3   b , another partially exploded view of the knife-style gate valve with elastomeric liner  10  according to the preferred embodiment of the present invention is disclosed. This figure shows the distal body liner  80  installed inside of the distal body assembly  25  and held in place via a friction fit. Likewise the near body liner  75  (not visible in this configuration) is placed within the near body assembly  20 . The gate  60  and wiper  65  remain as depicted in  FIG. 3   a  awaiting installation. 
     Referring now to  FIG. 3   c , still another partially exploded view of the knife-style gate valve with elastomeric liner  10  according to the preferred embodiment of the present invention is depicted. This figure shows the gate  60  and wiper  65  in place against the distal body assembly  25  and distal body liner  80  awaiting additional construction. As aforementioned described the near body liner  75  (not visible in this configuration) remains placed within the near body assembly  20  awaiting additional manufacturing steps. 
     Referring finally to  FIG. 3   d , yet another partially exploded view of the knife-style gate valve with elastomeric liner  10  according to the preferred embodiment of the present invention is shown. This figure shows all materials made of elastomeric materials, namely the gate  60 , the wiper  65 , the near body liner  75  and the distal body liner  80 , placed within the confines of the near body assembly  20  and the distal body assembly  25 . Such components are held in place and are secured via the first connection bolts  30  and the second connection bolts  55  as shown in  FIG. 1  and  FIG. 2 . Said construction is not unlike that afforded by conventional gate valves. The time interval between the construction steps depicted in  FIG. 3   a  and  FIG. 3   d  is envisioned to be only minutes. Similar but reverse construction techniques would be followed for repair and/or rebuilding activities. 
     In a non-limiting exemplary embodiment of the present invention  10 , the gate valve assembly  15  may be intercalated between the distal and near body assemblies  25 ,  20 . The hand wheel  45  preferably actuates the gate valve assembly  15  between the distal and near body assemblies  25 ,  20  respectively, and subjacent to the stem  50 . Advantageously, rotation of the hand wheel  45  causes the gate  60  to linearly reciprocate through the wiper  65 . In this manner, the stem  50  preferably rotates in sync with the hand wheel  45 . 
     It is envisioned that other styles and configurations of the present invention can be easily incorporated into the teachings of the present invention, and only one particular configuration shall be shown and described for purposes of clarity and disclosure and not by way of limitation of scope. 
     The preferred embodiment of the present invention can be utilized by the common user in a simple and effortless manner with little or no training. It is envisioned that the knife-style gate valve with elastomeric liner  10  would be constructed in general accordance with  FIG. 1  through  FIG. 3   d.    
     The majority of the components used in the knife-style gate valve with elastomeric liner  10  such as the near body assembly  20 , the distal body assembly  25 , the first connection bolts  30 , the yoke  35 , the bonnet  40 , the hand wheel  45 , the stem  50 , and the second connection bolts  55  would be made using conventional materials and follow conventional manufacturing techniques. The specialized components of the wiper  65 , the near body liner  75  and the distal body liner  80 , would be made using elastomeric materials. Said components would be the only components of the knife-style gate valve with elastomeric liner  10  that would come in contact with controlled or transferred material, hence the name “wetted”. Said assembly of the gate  60 , the wiper  65 , the near body liner  75  and the distal body liner  80 , within the near body assembly  20  and distal body assembly  25  would follow the specific steps outlined within  FIGS. 3   a - 3   d . This procedure would allow for fast manufacture as well as fast repair using normal procedures. At this point in time, the knife-style gate valve with elastomeric liner  10  is ready for specific application as a gate valve. 
     The knife-style gate valve with elastomeric liner  10  would be installed within a piping system using the system connection apertures  58  in the same manner as any other gate valve. The overall dimensions of the knife-style gate valve with elastomeric liner  10  would closely follow those of conventional gate valves allowing for retrofit applications. 
     The knife-style gate valve with elastomeric liner  10  would be held in place via the first connection bolts  30  as would be normally expected. At this point in time the knife-style gate valve with elastomeric liner  10  would be placed in service controlling abrasive fluids as aforementioned described until replacement or repair would be required. 
     The foregoing descriptions of specific embodiments have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit to the precise forms disclosed and many modifications and variations are possible in light of the above teachings. The embodiments were chosen and described in order to best explain principles and practical application to enable others skilled in the art to best utilize the various embodiments with various modifications as are suited to the particular use contemplated.