Abstract:
A gas pressure regulator is disclosed that includes a reciprocating piston that engages and disengages from a seat to open the higher pressure and lower pressure sides of the regulator to one another. The regulator includes an elastomer seal between the seat and the piston that has an ignition rating sufficient to avoid combustion in the presence of oxygen at pressure differentials that are a factor of between 5 and 10 between the higher pressure and lower pressure sides of the regulator.

Description:
RELATED APPLICATIONS 
       [0001]    This is a divisional of Ser. No. 14/327,861 filed Jul. 10, 2014 for “Medical Gas Manifold.” Ser. No. 14/327,861 is a continuation of Ser. No. 14/066,174 filed Oct. 29, 2013 for “Medical Gas Manifold.” 
     
    
     BACKGROUND 
       [0002]    The present invention relates to the safe and proper handling of gases in the medical (e.g., hospital) environment. 
         [0003]    A number of gases are used in the hospital environment, both for patient care and for other various purposes. 
         [0004]    Oxygen is typically supplied for patients who require supplemental oxygen as part of their care. Nitrous oxide (N 2 O) has anesthetic properties and is typically supplied to operating rooms (surgical suites) for preoperative and operative procedures. Nitrogen is typically used to power mechanical items such as surgical equipment. Carbon dioxide is typically used to handle (e.g., inflate or suspend) tissue during surgery and also in some types of laser surgery. “Medical air” is typically used for patient inhalation via ventilators or for breathing treatment. “Instrument air” is another term for compressed air, typically used to drive mechanical tools. Additionally, mixtures of these gases and other gases, as well as vacuum capabilities, are typically part of the hospital environment. 
         [0005]    In typical medical or hospital applications, oxygen is best delivered for end use at pressures of around 55 pounds per square inch (psi), nitrous oxide at about 50 psi, nitrogen at about 175 psi, carbon dioxide at about 50 psi, medical air at about 55 psi, and instrument air at about 175 psi. 
         [0006]    The amounts of such gases used in a hospital tend to be rather large. Thus, in accordance with the ideal gas law (or its more sophisticated versions), the volume required to store gases at room temperature and typical delivery pressures also would be very large. Because of that, and as is the case in other gas-delivery circumstances, hospital gases are typically stored in groups (“banks”) of either high-pressure cylinders (e.g,. at pressures up to about 2500 psi) or cryogenic tanks (oxygen and nitrogen) and then delivered at the lower end use pressures using appropriate regulators and associated hardware. 
         [0007]    Because of the hospital environment, such regulators and related delivery hardware must meet stringent requirements that are not typical elsewhere; i.e., the hospital context is unique in a number of circumstances. Relevant best practices are well understood and have become codified in various regulations. These include (but are not limited to) the NFPA regulations in United States (e.g. 38 CFR 51.200), the CSA regulations in Canada, and the ISO regulations in Europe. 
         [0008]    The combinations of different gas sources, different pressures at both the source and delivery positions, and the various regulations applicable to the hospital or medical environment, all create complications that must be addressed in the gas delivery system. 
         [0009]    As used herein, the term “regulator” refers to a mechanical device that controllably reduces the pressure of an incoming gas and delivers it for use at a specified lower pressure (or pressure range). Accordingly, in the hospital environment regulators must transfer gas from high-pressure cylinders (up to 2500 psi) to the intended pressures just described, or from cryogenic cylinders. Although cryogenic cylinders store gas as a liquid, they still contain internal gas pressures of about 300 psi. 
         [0010]    One of the requirements for the gas delivery system—particularly in hospitals—is redundancy; i.e., the gas supply cannot be interrupted under any normal circumstances (e.g., repair or resupply) or even in many abnormal circumstances. Because of that, hospitals typically have at least a primary source of gases (the “primary side”) and a complementary back up set of gases referred to as the “secondary side.” In turn, the hospital gas delivery system must likewise include primary side regulators and other delivery equipment and separate secondary side regulators and delivery equipment. In best practices, the flow of each and every gas will continue without interruption if one side is shut off. The most typical circumstance is to transfer from the primary side to the secondary side so that the primary side tanks can be replaced with full ones when empty. Additionally, other circumstances (both typical and unforeseen) can also create interruptions and the gas regular system must be able to handle such events without allowing interruptions in the gas flow. 
         [0011]    Conventionally, the required equipment and redundancy is built from existing (“off-the-shelf”) components. Although such readily available parts can superficially lower initial costs, such conventional equipment (e.g., regulators, valves, fittings) can suffer from certain disadvantages. 
         [0012]    As one disadvantage, certain polymer rubbers (elastomers) have properties that make them incompatible with certain hospital gases. Generally, some elastomers are compatible with oxygen, but not nitrous oxide or carbon dioxide (and vice versa). As an example, some halogenated elastomers give off toxic fumes when ignited. 
         [0013]    In particular, the (potentially) large pressure changes within regulators (e.g., from 2500 psi in a bank to 250 psi in a manifold) can produce adiabatic compression that significantly elevates the gas temperature. When the gas is oxygen in the presence of hydrocarbon-based elastomers (e.g., sealing O-rings and related parts), combustion can-and does-result. In particular, hydrocarbon rubbers such as polyurethane, styrene butadiene, polyisoprene and ethylene-propylene-diene ignite easily, and have high fuel value and heat release. 
         [0014]    Halogenated elastomers such as Viton® can favorably withstand higher temperatures than such other elastomers. For example, Viton® has a rated combustion temperature of about 400° F., while nitrile butyl rubbers are on the order of 212° F. Nevertheless, when halogenated elastomers burn, they tend to detrimentally release halogen gases and gas compounds. 
         [0015]    Some such halogenated elastomers tend to absorb carbon dioxide and nitrous oxide and then disperse such absorbed gases rapidly under a relatively large pressure release, such as those experienced in high-pressure-to-low pressure regulators. In turn, such release tends to physically harm (i.e., blister or blow out) the elastomer piece and thus destroy its function, and in turn the function of the entire regulator. Some non-halogenated polymers avoid the absorption problems, but (as noted previously) suffer from a tendency to ignite in the presence of oxygen undergoing adiabatic compression. 
         [0016]    As a result, in conventional regulators and structures incorporating regulators, some or all of the typical polymer fittings (e.g., o-rings, diaphragms, etc.) must be selected based upon the gas being used even though the equipment being fitted is otherwise identical in most or all respects. In a sense, this bases the polymer choice on potential disadvantages rather than on potential advantages. Such fittings can reduce efficiency and thus increase overall cost, for both manufacture and use (maintenance). In some cases, different regulators with different elastomers are used for the different gases, but at higher cost and lower efficiency. 
         [0017]    As a separate and distinct problem, the regulators used in hospitals, along with their associated valves, gauges and fittings need to stay structurally intact under pressure, and a user (e.g., maintenance worker) should not be able to remove items from the regulator structure while the pieces are pressurized. This is a safety issue. 
         [0018]    As a third distinct issue, the piston assemblies used in conventional regulators can permit larger than desired drops in pressure during flow. The elastomer diaphragms used in conventional regulators tend to have more “droop.” More specifically, pressure regulation is a function of inlet pressure. As the inlet pressure source is reduced, regulator delivery pressure may either rise or fall depending upon the regulator design. In both cases this is known as regulator “droop.” The side loading design of many regulator piston assemblies tends to increase both the friction and the droop of the assembly. Additionally, balancing the piston assembly on the line regulator also tends to increase friction and droop. 
         [0019]    As another independent problem, regulators must be serviced from time to time and are typically mounted on a wall. The nature of much conventional regulator construction, however, makes it very difficult to operate or repair a regulator while it is in position on the wall (“vertical”). Typically the regulator and a number of associated parts must be removed from the wall or it&#39;s housing, serviced, and then returned. This series of steps decreases efficiency, takes extra time, and thus increases the cost of use. 
         [0020]    Finally, in many conventional hospital gas delivery systems the user must review the manifold directly in order to understand the status (pressure and flow) of the various gases. Therefore, unless a person is constantly viewing or frequently inspecting the relevant gauges (or other output), real-time information will be delayed or in some cases missed altogether. 
       SUMMARY 
       [0021]    In one aspect, the invention is a gas pressure regulator that includes a reciprocating piston assembly that engages and disengages from a seat to open the higher pressure and lower pressure sides of the regulator to one another. The regulator includes an elastomer seal between the seat and the piston assembly that has an ignition rating sufficient to avoid combustion in the presence of oxygen at pressure differentials that are a factor of between 5 and 10 between the higher pressure and lower pressure sides of the regulator. 
         [0022]    In a second aspect, the invention is a gas pressure manifold that is particularly suitable for medical industry applications. In this aspect, the invention includes at least one pair of bank regulator bodies for supporting regulators that moderate the flow of high-pressure gas from a gas source while providing redundancy for continuous gas flow through at least one regulator at all times, at least one pair of line regulator bodies for holding line regulators in gas communication with the bank regulators, and with the bank regulator bodies and the line regulator bodies being joined by at least one brace bar for preventing the brace bar from being removed when the forgings are under pressure. 
         [0023]    In another aspect, the invention is a gas pressure regulator that includes a regulator body, a piston assembly in the regulator body, a spring chamber, a spring in the spring chamber, and a cup shaped piston diagram in the spring chamber and surrounding the portions of the spring adjacent the piston valve for eliminating or minimizing the flexing of various materials under pressure in the regulator. 
         [0024]    In another aspect, the invention is a medical gas alarm system for use in a healthcare facility having medical gas systems which severally deliver a plurality of medical gases to a plurality of locations in the healthcare facility and having a network of computer devices. In this aspect, the invention includes a gas pressure manifold included in the network of computer devices in which the gas pressure manifold includes bank regulators, line regulators, and pressure sensors associated with each regulator, and network connectors between the sensors and the remainder of the network for remote monitoring of cylinder pressure levels, alarm status, event logs, and similar items from any computer on the network. 
         [0025]    The foregoing and other objects and advantages of the invention and the manner in which the same are accomplished will become clearer based on the followed detailed description taken in conjunction with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0026]      FIG. 1  is a perspective view of the manifold external housing. 
           [0027]      FIG. 2  is a perspective view of the manifold with the housing removed. 
           [0028]      FIG. 3  is a front elevational view of the manifold and the control box. 
           [0029]      FIG. 4  is a front elevational view of a second embodiment of the manifold and control box. 
           [0030]      FIG. 5  is a front elevational view of the forging portion of the manifold. 
           [0031]      FIG. 6  is a side elevational view of the forging of  FIG. 5 . 
           [0032]      FIG. 7  is an exploded perspective view of one of the line regulators in the context of the manifold. 
           [0033]      FIG. 8  is a perspective exploded view of one of the bank regulators in the context of the manifold. 
           [0034]      FIG. 9  is a cross-sectional view of a bank regulator. 
           [0035]      FIG. 10  is a cross-sectional view of a line regulator. 
           [0036]      FIG. 11  is a schematic diagram of a network that includes the manifold. 
           [0037]      FIG. 12  is a perspective view of a single forging according to the invention. 
           [0038]      FIG. 13  is a rear perspective view of a manifold according to the invention. 
           [0039]      FIG. 14  is an exploded perspective view of the inlet and inlet filter according to the invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0040]    The terms “hospital” and “medical” are used in a descriptive rather than limiting context in this specification, and the invention&#39;s advantages apply in the general context regardless of whether or not the particular environment is a hospital per se. 
         [0041]      FIG. 1  is a perspective view of the medical gas manifold of the invention inside of a housing broadly designated at  20 . In typical embodiments, the housing is formed of an appropriate sheet-metal, the nature of which should be consistent with the local environment and medical applications, but that otherwise can be selected by those of ordinary skill in the art without undue experimentation. 
         [0042]    The manifold includes an inlet fitting  21  and an outlet fitting  22 . A reserve header inlet  23  is positioned adjacent the inlet  21 , and a relief valve fitting  24  is adjacent the outlet fitting  22 . In exemplary embodiments, the inlet portion of the bank regulator ( 43 ,  70 ;  FIG. 2 ) also includes a gas-inlet filter ( FIG. 14 ) which is formed of a shaped portion of sintered bronze, a material that has improved heat retention, acts as a flame arrestor, has better particle retention, and slows gas velocity better than some other materials. 
         [0043]    A control box broadly designated at  25  is positioned adjacent the housing  29  and can be mounted on the same back panel  26  as the main portions of the manifold. 
         [0044]    To assist in use, the manifold includes a left bank pressure gauge  27 , a right bank pressure gauge  30  and a delivery pressure gauge  31 . These are mounted in (or flush with) a face plate  32  which includes a plurality of light emitting diode (LED) indicators. 
         [0045]    Each respective bank has an empty signal LED  33 , a ready signal LED  34  and an in use signal LED  35 . A changeover LED  36  indicates when the manifold is switching between banks. The forging  41  helps to (among other advantages) eliminate the leaks to which conventional separate items are more susceptible. 
         [0046]      FIG. 2  is a perspective view of the manifold broadly designated at  40  with the housing  29  removed. The manifold is formed from one or more forgings which are broadly designated at  41 . The forging in an isolated context is perhaps best illustrated in  FIGS. 5, 6 and 12 . 
         [0047]    The manifold  40  includes at least one pair of bank regulator bodies  124  (e.g.,  FIGS. 6 and 7 ) for supporting bank regulators  43 ,  70  that moderate the flow of high-pressure gas from a gas source while providing redundancy for continuous gas flow through at least one of the bank regulators at all times. At least one pair of line regulator bodies  103  hold line regulators  52 ,  71  in gas communication with the bank regulators  43 ,  70 . 
         [0048]    The bank regulator bodies and the line regulator bodies are joined by at least one brace bar  28  so that the relationship prevents the brace bar from being removed when the forgings are under pressure. 
         [0049]    Some features of the manifold, it&#39;s structure, and its operations can be identified by following the flow of gas in the illustrated embodiments. Thus, gas from a bank (of tanks or cryogenic cylinders) enters the manifold through the inlet fitting  21  and the inlet pipe  42 , from which it reaches the right (or “primary”) side bank regulator  43 . More detailed views of the bank regulator  43  are set forth in  FIGS. 8 and 9 . Those skilled in the art understand, of course, that “primary” and “secondary” refer to the mode of use rather than to any absolute right or left orientation. 
         [0050]    A pressure switch  44  is connected to the right bank regulator  43  along with a bleed valve  45  and a bank pressure gauge  46 . A solenoid valve  47  and (optionally) a dome pressure regulator (not illustrated in this embodiment) help control the operation of the bank regulator  43  through the various piping connections which, for purposes of clarity, are not all individually labeled. Their structure and function are nevertheless both typical and well understood by the skilled person. 
         [0051]    The vertical portion of the forging  41  that extends outwardly from the bank regulator  43  includes a check valve (not shown in  FIG. 2 ) as well as the reserve header port  51 . 
         [0052]    As generally well understood by the skilled person and as explained in the Background, the purpose of the bank regulator  43  is to reduce the high pressure of the gas received from the bank tanks or cryogenic cylinders to an intermediate pressure which is more suitable for the more detailed control provided by the line regulators. 
         [0053]    Accordingly,  FIG. 2  likewise illustrates a right (primary) line regulator  52  which is likewise fixed in a portion of the forging  41 . The right line regulator  52  delivers gas at the desired pressure through the outlet  22  which is illustrated in the context of a zero clearance fitting  53 . A similar zero clearance fitting  54  is on the relief valve outlet  24 . 
         [0054]      FIG. 2  also illustrates an intermediate relief valve  55 , a line relief valve  56 , a vent valve  57 , and a service valve  64 . The intermediate relief valve  55  is connected to the overall relief valve  24  through a tube  61  and the line relief valve  56  is likewise connected to this destination by the tube  62 . In  FIG. 2  the tubes  61  and  62 , along with the smaller tubes which are unnumbered for clarity purposes, are formed of rigid copper tubing. This is in accordance with ISO standards. Depending upon the regulatory overlay in the country or jurisdiction of use, some or all of the tubing can be formed of an appropriate flexible polymer material provided it is otherwise consistent with the physical, chemical, safety, and other relevant requirements. 
         [0055]      FIG. 2  also illustrates a service bleed valve  63  and a knobbed service valve  64 . 
         [0056]      FIG. 2  also illustrates a plurality of pipe fittings, connectors, elbows, and the like each of which is generally well understood both in terms of their general structure and function and their structure and function in the context of the manifold of the invention. 
         [0057]      FIG. 3  illustrates all of the items in  FIG. 2 , as well as several that are clearer in the front elevational view. 
         [0058]    Some of these items include the respective locking collars  65  on the inlet pipes  42  (and the corresponding secondary inlet pipe  29 ) and respective isolation (ball) valves  66  located in the forging  41  between each respective bank regulator  43  and line regulator  52 . It will be generally understood, of course, that where identical items are shown in parallel with one another, they are the same item and serve the same purpose, with the only difference being that one set serves a gas bank or cylinders entering the manifold from the left and the other serves the gas bank or cylinders entering the manifold from the right. For example, an inlet fitting  37  corresponds to the secondary inlet in the same manner as the inlet fitting  21  corresponds to the primary inlet. 
         [0059]      FIG. 3  also illustrates that a plurality of electrical wires and cables help control various items. Many of these pass through the cable covers  67  illustrated on the left-hand side of  FIG. 3  from which they enter the control box  25 . The nature of the electrical controls is generally otherwise conventional and well understood by those of skill in this art. As set forth with respect to  FIG. 11 , these controls also help connect the manifold to a hospital computer network (or its equivalent). 
         [0060]    In some embodiments the manifold can include a dome pressure regulator which can be connected to the solenoid valve and the bank regulators. Although positioning is a matter of design choice, in the illustrated embodiments, when a dome pressure regulator is included, it can be positioned in the lower portions of the housing  20 . 
         [0061]    Each of the regulators is associated with a respective check valve. The check valves are maintained in the portion of the forging extending vertically above each respective bank or line regulator. For the sake of completeness, the left (secondary) bank regulator is labeled at  70  and the left (secondary) line regulator at  71 . 
         [0062]      FIG. 4  is a front elevational of view of a second embodiment of the invention broadly designated at  38  which meets the Canadian (i.e., CSA) design and regulatory criteria. Much of the regulator is generally the same as described with respect to  FIG. 3 , but under CSA standards, a check valve cannot be positioned between the line regulator and the outlet. 
         [0063]    Accordingly, in this embodiment the line regulators  71  and  52  are connected to isolation valves  72  and  73  respectively. Pressure relief valves  74  and  75  are also connected to the regulators  71  and  52 . The isolation valves  72  and  73  are connected to a sub-manifold  76  which provides the functional connection to the vent valve  57  and the service valve  64 , as well as a common outlet  77 . This embodiment also includes line regulator pressure gauges  80  and  81  respectively. 
         [0064]    The remaining items in  FIG. 4  are the same structurally and functionally as in  FIG. 3  and carry the same reference numerals. 
         [0065]      FIGS. 5 and 6  illustrate the forging  41  somewhat more clearly in partial isolation from a number of the items in  FIGS. 1-4 . A number of the items are, of course, the same as in  FIGS. 1-4  and thus carry the same reference numerals. In particular,  FIGS. 5-8  show two forgings  41  stacked on top of one another and connected by the brace bar  28  and with the intermediate isolation valves  73 . 
         [0066]    In the manifold of the invention the bank regulator bodies  124  are part of a common forging  41  and the line regulators are part of a common forging  41 , and the brace bar  28  is fixed to each of the common forgings. In the illustrated embodiment, the brace bar  28  is shown having several rectangular plate portions, but it will be understood that this configuration is exemplary of the possibilities rather than limiting. 
         [0067]    In turn, the common forgings  41  comprise respective metal bridging webs  48  between the bank regulator bodies and the line regulator bodies, and the brace bar  28  is fixed to each of the respective metal bridging webs. 
         [0068]    In exemplary embodiments, the regulator bodies and the brace bar  28  are formed of metal. 
         [0069]    In the CSA version illustrated in  FIG. 4 , the bank regulator bodies are formed in a common forging, but the line regulator bodies are separate. Thus, the brace  28  bar is fixed to the common bank regulator forging and then individually to the line regulator bodies  103 . 
         [0070]    Some of the items that are more clearly illustrated include, however, the handles  83  on the isolation valves  73 .  FIGS. 5 and 6  also more clearly illustrate the respective inlet for the gas  84 , the pressure gauge  85  and the switch  86 . 
         [0071]      FIG. 7  is an exploded view of the left line regulator  71  and  FIG. 10  is a corresponding cross-sectional view.  FIG. 7  illustrates the regulator spring  90  which is received in the spring chamber  91  and bears against a cup-shaped piston diaphragm  95 . The piston diaphragm  95  surrounds portions of the spring  90  adjacent the piston assembly  101  and its seat  97  and helps minimize or eliminate the oblique flexing that the spring  90  would otherwise undergo (or exert) under pressure. The spring pressure (and thus the regulator&#39;s set pressure) can be adjusted using the adjustment screw  92  and it&#39;s locknut  93 . Respective spring buttons  94  are positioned at the top and bottom of the spring  90 . In exemplary embodiments the bank regulator spring  114  is formed of stainless steel, because it has a higher threshold temperature for promoted combustion than some other typical spring metals. 
         [0072]    As noted previously, upper and lower spring buttons  94  are positioned at opposite ends of the spring  90 , and each of the spring buttons includes a gimbal-type indentation (e.g.,  FIGS. 9 and 10 ). The adjustment screw  92  includes a well-rounded nose  132  ( FIG. 10 ) that engages the gimbal on the upper spring button, and a rounded projecting floor portion  97  on the cylindrical piston diaphragm  95  engages the lower spring gimbal. These parts cooperate to mitigate the effect of varying spring squareness and help direct the regulator forces linearly rather than obliquely. In turn, these items keep the regulator parts aligned during operation, which increases the regulator&#39;s accuracy and precision, and reduces its droop. The cup shape of the piston diaphragm  95  also captures the spring and spring buttons in a manner that allows the regulator parts to be removed from the regulator bodies while the regulator bodies remain fixed with the remainder of the manifold. From a practical standpoint, this means that the regulator parts can be removed and serviced (or replaced) while the remainder of the manifold remains in its in-use location and position (which is often a vertical orientation). In contrast, the multiple parts of a conventional regulator tend to separate quickly (and disadvantageously) unless the entire regulator—and in some cases the entire manifold—is removed from its in-use position and then serviced elsewhere. 
         [0073]    The piston diaphragm of the invention is illustrated at  95 , and in exemplary embodiments is formed of brass. As  FIG. 7  illustrates, the spring  90  and its buttons  94  are positioned between the piston diaphragm  95  and the spring chamber  91 . A pusher post button  96  is beneath and bears against the piston diagram  95  on one side and the seat ring  97  with an O-ring (too small to be clear in this illustration) on the other side. The piston diaphragm  95  carries an O-ring  100  around its circumference generally about halfway between the top and the bottom of the diaphragm  95 . A piston assembly  101  is beneath and bears against the seat ring  97  and is surrounded by the seat spring  102 , which closes the seat. The spring chamber  91  threads into the regulator body  103  and a body O-ring  104  helps create and preserve a seal against leakage in the overall regulator structure. 
         [0074]    As illustrated in both  FIG. 7  and  FIG. 10 , the piston assembly  101  is free to reciprocate in its piston chamber  99  without the conventional sealing O-ring that typically surrounds such a piston in a regulator (e.g., the O-ring  118  in the bank regulator). Avoiding the O-ring helps the piston move more smoothly, which in turn reduces the droop. 
         [0075]    In exemplary embodiments, and as set forth with respect to  FIG. 10 , an HNBR elastomer is incorporated in the piston assembly  101  to provide a higher temperature rating. 
         [0076]      FIG. 7  also illustrates that in a manner analogous to the openings in the bank regulators (e.g.,  FIG. 6 ), the regulator body  103  includes a bleed valve opening  105 , a pressure gauge port  106 , and (if desired) a pressure switch port  107 . 
         [0077]    The remaining items in  FIG. 7  are the same as shown in and described with respect to  FIGS. 1-6  and will not be repeated here. 
         [0078]      FIG. 8  is an exploded view similar to  FIG. 7 , but illustrating the left bank regulator  70  in the exploded view.  FIG. 8  illustrates an adjustment screw  110  that carries an O-ring  111  and a locknut  112 . The spring chamber is illustrated at  113  and the spring at  114 . The spring rests between the piston diaphragm  115  (which again includes an O-ring  117 ) and a spring button  116 . 
         [0079]    A seat ring  120  is beneath piston diagram  115  with a pusher post button  121  in between. The seat ring  120  carries an O-ring (not shown in  FIG. 8 ). The seat ring can be formed of monel alloys (i.e., specialized nickel-copper alloys), brass, or stainless steel. The piston assembly is illustrated at  122  and rests in a seat spring  123 . The seat spring  123  is preferably formed of austenitic nickel-chromium based “superalloy” (e.g., Inconel 750) or of a copper beryllium alloy. In turn, these parts rest in the regulator body  124  with pressure being maintained in place by the O-ring  125 . The remaining elements in  FIG. 8  are either the same as those described and illustrated in the exploded portion, or in the preceding drawings. 
         [0080]      FIG. 9  is a cross-sectional view of the bank regulator  70  of  FIG. 8  and  FIG. 10  is a cross-sectional view of the line regulator of  FIG. 7 . 
         [0081]    Most of the elements illustrated in  FIGS. 9 and 10  have already been described, but  FIGS. 9 and 10  include some additional details.  FIGS. 9 and 10  illustrate the regulators in their open positions. 
         [0082]      FIG. 9  illustrates more details of the piston assembly  122  in a line regulator. In the illustrated embodiment, the piston assembly includes a piston base  87 , a piston stem  88  and the O-ring  130  between the base  87  and the stem  88 . An O-ring  127  is on the seat ring  120 , and the O-ring  130  is between the piston assembly and the seat  120 . An O-ring  118  is positioned at the bottom of the piston assembly  122 . 
         [0083]    In particular, the seat O-ring  130  functions as the seal between the high pressure (e.g., 2500 psi) and lower pressure (e.g., 250 psi) portions of the regulator. Because of that, in the invention the O-ring  130  is formed of an elastomer that can withstand adiabatic compression of a factor of at least 5, and preferably 10 (pressure to pressure) without igniting in oxygen. Certain rigid engineering polymers meet this requirement, but are not sufficiently flexible for the regulator&#39;s purpose. Various combinations of polysilphenylene-siloxane and polyphosphagene have high temperature combustion rations, but a highly favorable choice appears to the hydrogenated nitrile butyl rubber (“HNBR”). 
         [0084]    HNBR has good viscoelastic properties, a service temperature range of between about −40° C. to +150° C. (−40 to 300 F.), resistance to fluids of various chemical compositions and excellent resistance to strongly alkaline and aggressive fluids. HNBR is a derivative of nitrile rubber, which is hydrogenated in solution using precious metal catalysts. Different grades can be made by precise control of the proportion of unconverted double bonds in the material. HNBR is resistant to thermo-oxidative aging, with typical service life ratings that correspond to a long-term exposure of 1000 hours at 150° C. (about 300 F.). 
         [0085]      FIG. 10  shows some additional details about the line regulator. These include the rounded nose  132  on the adjustment screw  92 .  FIG. 10  also shows the O-ring  133  on the seat ring  97  as well as the O-ring  134  in the piston assembly  101 . 
         [0086]      FIG. 12  is a perspective view of a single forging  41  and illustrated the regulator bodies  124  and the metal bridging web  48 . 
         [0087]      FIG. 13  is a perspective view of the manifold  40  that illustrates the manner in which the brace bar  28  connects two forgings  41  together. 
         [0088]      FIG. 14  is an exploded perspective view of the inlet pipe  42  illustrating the sintered bronze filter  58 . The filter  58  has a body that includes a longitudinally-projecting portion that has a frustum shape in the illustrated embodiment. In exemplary embodiments, the filter  58  is formed of sintered bronze with a 40 micron size. The volume and shape of the filter  58  helps slow gas velocity, improve heat rejection, and retain particles more efficiently than simpler shapes.  FIG. 14  also illustrates a retaining ring  59  for the filter  58  and an O-ring  68  for the inlet pipe  42 . 
         [0089]      FIG. 11  illustrates the use of the manifold in connection with network capability for a medical air system. This is consistent with the TOTALALERT™ system from Atlas Copco/BeaconMedaes (Rock Hill, S.C.). This aspect off the invention is also consistent with the systems described in U.S. Pat. Nos. 7,768,414; 7,145,467; and 6,987,448, the contents of which are incorporated entirely herein by reference. 
         [0090]    An exemplary embodiment is a medical gas alarm system for use in a healthcare facility having a medical gas system which delivers a plurality of medical gases to a plurality of locations in the healthcare facility and having a network of computer devices. In this context, the invention includes a gas pressure manifold that communicates with the network of computer devices. As already described, the gas pressure manifold includes bank regulators, line regulators, and pressure sensors associated with each regulator. Network connectors between the sensors and the remainder of the network permit remote monitoring of cylinder pressure levels, alarm status, event logs, and similar items, using any computer on the network. The system likewise typically includes a network hub (or equivalent), an Internet connection (with firewall), and an email server. 
         [0091]    In most cases, the medical gas system includes vacuum pumps and medical air pumps that are also in communication with the network. In exemplary embodiments, any and all alarm devices in the system communicate with the network. 
         [0092]      FIG. 11  illustrates that the manifold (illustrated in its housing  20 ) can be networked to an appropriate Ethernet hub  136 . The hub  136  (or its equivalent) is in turn connected to a computer  137  with web browsing capability or to any equivalent device such as a tablet or smart phone. An alarm  140  is connected to the network as are other portions of the medical air system. These are symbolically illustrated at  141 ,  142 , and  143  in the drawings, and can represent various aspects of the medical air system, such as the medical air supply  141 , a crawl-type vacuum  142 , or a lubricated rotary vane vacuum  143 . 
         [0093]    An email server  144  is connected to the network and can communicate internally through the hub  36  or with the Internet  145 , with a firewall  146  typically being included for security purposes. The email server can generate messages that, using the Internet, can be directed to one or more cellular phones  147  or their equivalent; i.e. the term “cellular phone” is used in a broad sense to incorporate devices that can receive text messages, email, or other communications, including but not limited to smart phones and tablet computers. Additionally, such messages can be received by more conventional computers (“PC&#39;”s or “laptops”) that have either Wi-Fi or cellular capability or both depending upon context. 
         [0094]    The TOTALALERT™ network monitors medical air, medical vacuum, medical master alarm, medical area alarms, and now the medical manifold of the invention. No additional software is required and the equipment on the network reside as IP points on the user&#39;s intranet. One key feature of the TOTALALERT™ network is that a single web page displays all of the equipment on the network. Although other systems may add embedded software to a product, none appear to include a centralized web page from which all of the individual components can be monitored. 
         [0095]    In the drawings and specification there has been set forth a preferred embodiment of the invention, and although specific terms have been employed, they are used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention being defined in the claims.