BRPI0721924A2 - SPRING-FREE COMPRESSOR VALVE - Google Patents

Description

Patent Descriptive Report for "SPRING-FREE COMPRESSOR VALVE".

Claimed Priority

This application is a continuation in part of US Patent Application 11 / 057,770, filed February 14, 2005, and incorporated herein by reference.

Background

This section is intended to introduce the reader to various aspects of the art which may be related to various aspects of the present invention, which are described and / or claimed below. This discussion is believed to be useful in providing the reader with subordinate information to facilitate a better understanding of the various aspects of the present invention. Accordingly, it should be understood that these statements should be read in this light, not as prior art admissions.

In a variety of applications, fluids are compressed and

transported through a compressor valve. Generally, on one side upstream of the valve, fluid pressure is periodically raised, for example by an oscillating piston. While the fluid is in a compressed state, the valve opens to allow flow of the compressed fluid to the other side of the valve. Typically, this continues until the fluid pressure drops, and the valve closes, thereby sealing the compressed fluid on the other side of the valve. Over time, this cycle is typically repeated a large number of times. For example, some reciprocating compressors run at 300-1800 RPM, which rotate their valves 5-30 times per second.

Compressor valves often include wear components, in particular of which they are springs. In many valves, a spring pushes the valve closed when the force of the pressure difference across the valve is less than the force of the spring. Over the life of such valves, the spring may go from a compressed state to a relaxed state a large number of times and this cycling may cause the spring to fatigue. Due to such wear, compressor valves are often subject to expensive maintenance.

Brief Description of the Drawings

These and other features, aspects and advantages of the present invention will be better understood from the following detailed description with the accompanying drawings in which similar characters represent similar parts throughout the drawings, in which:

Figure 1 is a cross-sectional view of one embodiment of a magnetically actuated concentric ring valve;

Figure 2 is a cross-sectional view of a magnet-operated gate valve on a compressor;

Figure 3 is a cross-sectional view of one embodiment of a magnet-actuated trigger valve on a compressor;

Fig. 4 is a cross-sectional view of one embodiment of a magnet-driven ring valve using both a single ring and a plurality of generally identical (not necessarily concentric) rings in a compressor;

Figure 5 is a cross section of a trigger; Figure 6 is a cross-sectional view of another embodiment of a rack;

figures 7 and 8 are exploded perspective views of the trigger

Figure 6;

Figure 9 is a partial cross-sectional view of another embodiment of a trigger valve;

Fig. 10 is a perspective view of one embodiment of a compressor including one or more of the features illustrated in Figs. 1-9; and

Figure 11 is a cross section of the compressor of Figure 10. Detailed Description of Specific Modalities

One or more specific embodiments of the present invention will be described below. Such embodiments described are only examples of the present invention. Additionally, in an effort to provide a concise description of these exemplary embodiments, all features of an actual implementation may not be described in the descriptive report. It should be appreciated that the development of any such actual implementation, as in any engineering project or design, must be made in numerous implementation specific decisions to achieve developer specific goals, such as compliance with system-related and system-related constraints. which may vary from implementation to implementation. Furthermore, it should be appreciated that such a development effort can be complex and time consuming, but nevertheless it would be a routine task of design, manufacture, and manufacture for those with ordinary versatility having the benefit of this description.

An exemplary valve closure system is described below. Some embodiments of this system are particularly suitable for reciprocating compressors which, in some embodiments, do not employ springs and induce the valve in the closed direction by the generated force of 15 magnets positioned to repel each other. Other applications are envisioned, and different techniques for replacing the spring component in such valve assemblies are also contemplated.

Referring to Figure 1, the seat 10 has passages 12 leading to a seating surface 14. A flow represented by arrow 16 progresses in the development of pushing pressure against valve member 18 to displace it from seating surface 14, wherein the flow passes through the shield 20 via the passages 22 as shown by arrow 24. Aligned with the valve member 18 and extending into the shield is a small hole 26 leading to a larger hole 28. A shoe 30 with a hole 32 is held or mounted in hole 28. A magnet 34 having a hole 36 aligned in fluid communication with hole 32 is mounted on shoe 30. A button 38 passes over a portion of shoe 30 and is slidably fixed. to it to limit their travel and to prevent the two from being detached in open-plate and ring valves. On trigger valves shown in figure 3, there is no shoe, instead a magnet is mounted directly on the trigger, and is not slidingly retained. A magnet 40 is mounted to knob 38 such that the magnet orientations 34 and 40 are such that the similar poles face each other creating a repulsive force, which is overcome by increasing pressure in the passages 12. elevating valve member 18 off seat surface

14. Valve member 18 may be any of a number of designs. A concentric ring design is illustrated in FIG. 1 and an open-plate design is shown in FIG. 2, a trigger valve is shown in FIG. 3, and a ring, both a single ring and multiple non-concentric rings thereof. The size for valve member 18 is shown in Figure 4. In all other respects, the embodiments illustrated in Figures 1, 2 and 4 generally work in the same manner. The mode currently discussed also works the same way, but there is no button (the magnet is on the trigger) in figure 3, and the trigger is not slidingly held.

In some embodiments, valve springs, particularly in compressor applications, may be eliminated using the magents. The magnets may be permanent or electromagnets or combinations of both. Magnets represent only one embodiment that eliminates springs for closing valves. Other solutions for replacing the springs in such valves may employ other forces that may be distributed through a physical slot without mechanical contact, and such modalities are also within the scope of the invention. Therefore, solutions employing various fields to cross a crack or employing fluid pressure optionally in conjunction with accumulators, for example, are all within the scope of the invention.

Consequently, the problem addressed by some modalities

One aspect of the present invention is to provide a valve design that can provide economical construction and reliable long service life. This objective is achieved in certain embodiments by eliminating the spring and using a force that preferably has a longer life cycle through the use of components that are less affected or are configured to better withstand the duty of cycling a valve. In one embodiment, the closing force is provided by the alignment of equal permanent magnet poles. Other embodiments are considered to distribute a clamping force through a device that is not prone to fatigue or wear as would be experienced in a spring wrapping application.

5 In some modalities, rapid acceleration and deceleration

Pushbutton 38, or other valve components cause detrimental inertia forces. As explained above, to drive the fluid flows indicated by arrows 16 and 24 at the appropriate times, the illustrated button 38 moves back and forth inside the shield 20. In certain embodiments, this cycle occurs relatively frequently, for example. example, once per cycle of a compressor. During this swing, when knob 38 reaches the end of its trip, it is brought to an impact stop of both seat 12 and shoe 30, depending on the direction knob 38 is moving. This impact rapidly decelerates knob 38, and rapid deceleration may give rise to relatively large inertial forces on knob 38. In particular, in some embodiments, large inertial forces may be applied to knob 38 by magnet 34, which causes the inertia. may have a large mass compared to the rest of knob 38. Therefore, magnet 34 may tension knob 38 during an impact.

The repeated voltage of rapidly slowing down the magnet 38

may tend to limit the life of button 38. In some embodiments, after a sufficient number of cycles, button 38 may become fatigued, and may need to be replaced, thus potentially increasing the operating cost of the valve illustrated. . This problem can be alleviated by some of the subsequent embodiments, which are believed to more evenly distribute internal inertial forces and reduce stress concentrations.

Figure 5 illustrates a trigger 50 and a shoe 52 believed to be resistant to some types of fatigue. In this embodiment, these components 50 and 52 have features that are generally rotationally symmetric and concentric about axis 57, but in other embodiments, these components, or a subset of their features, may not be concentric or rotationally. Symmetric ones, for example, may have an elliptical horizontal cross section. Trigger 50 and shoe 52 may be used in a variety of valve types, including the valves described above and valve 44 described below with reference to Figure 9.

The trigger 50 illustrated includes a body 70 and a magnet 72. In this embodiment, body 70 features a sprue nozzle 74, a head 6, a leg 8, and a shoulder 80. The sprue nozzle 74 is an artifact. of an injection molding process by which the body 70 is formed, and which is described below. In some embodiments, this feature 74 may be removed by machining. The illustrated head 76 defines a contact surface 82 against which a seat seals (e.g. the seat 46 shown in Figure 9), and in this embodiment, the contact surface 82 is angled downward to delimit a volume. usually in a truncated cone on the upstream side of the head 76.

The illustrated leg 78 extends downstream of the head 1576 and defines a distal surface 84. In this embodiment, the leg 78 has a generally circular, tubular conformation and demarcates an internal volume in a truncated cone. The leg 78 has a leg length 88 which is defined as the distance between the bottom of the magnet 72 and the distal surface 84, and a leg angle 90 which is defined as the angle between one side of the leg 78 20 and the axis 57. The angle of the leg 90 may be formed by an inner side of the leg 78 (as illustrated), an outer side of the leg 78, or both. In some embodiments, the angle of the leg 90 is greater than or approximately equal to 0 degrees, 5 degrees or 15 degrees.

The shoulder 80 may extend under the magnet 72 to retain the magnet 72. In this embodiment, the shoulder 80 meets the leg 78 in a thread 92, and the shoulder 80 extends a distance of the shoulder 94. In some embodiments , the fillet 92 may have a relatively large radius compared to the shoulder distance 94. For example, the fillet radius 92 may be greater than 20%, 50%, 80%, 120%, or 150%. Advantageously, a large fillet radius 92 is designed to diffuse the tension in the body 70 and attenuate the fatigue of inertial forces applied by the magnet 72. Between the head 76 and the shoulder 80, the 70 holds the magnet 72. In this embodiment, the magnet 72 has a generally truncated cone shape, with a magnet angle 96 defined as the angle between one side of the magnet 72 and the axis 57. The magnet 72 can be any of 5 one vari types of magnets, such as a neodymium magnet or other rare earth magnet, and the angle of the magnet 90 may have a positive, negative, or generally zero value (for example, the angle may be sharp or the sides may be be parallel). Advantageously, during an impact, the illustrated magnet 72 is imagined to distribute part of its inertia load to the body portion 70 along its sides, thereby potentially still reducing stress concentrations in the body 70.

In some embodiments, trigger 50 is formed by injection molding of body 70 around magnet 72. For this purpose, magnet 72 is initially positioned within a mold that is complementary to body 70, and a plastic, such as a carbon fiber infused thermoplastic or other material is injected into the mold around the magnet 72. As a result of this insert molding process, the trigger body 70 holds the magnet 72 without an intermediate member or substance. Other embodiments, such as those described below, with reference to FIGS. 20-7, may support magnet 72 with an intermediate member.

The shoe 52 in the present embodiment includes a repeating magnet 98, a shoe body 100, a shock absorber 102 and a fluid drainage passage 104. The repellent magnet 98 may be oriented relative to the magnet 72 he drives the magnet 25 25 away from the shoe 52 with a magnetic force. The shoe body 100 may be injection molded around the repellent magnet 98.

The shape of the shoe body 100 shown is complementary to the internal volume 86 defined by the leg 78 and defines an impact surface 106. In the present embodiment, the shock absorber 102 is disposed adjacent the shoe body 100 opposite to the one. However, in other embodiments, the shock absorber 102 may be positioned on the other side between the impacting surface 106 and the distal surface 84 of the leg 78. The shock absorber 102 may be made of nylon. lon, elastomer, or other suitable resiliently compressible materials.

In operation, a high fluid pressure (e.g., a gas pressure, such as air pressure) in the inlet passage 56 (as illustrated in figure 9), can trigger trigger 50 toward shoe 52. This movement is indicated by the arrow 108. As the trigger 50 translates downstream, the fluid in internal volume 86 escapes through the fluid drainage passage 104. The trigger 50 translates into the trigger container 64 to the distal surface 84 of the leg. 78 reach impact surface 106, and while it is translating, trigger container 64 and / or shoe 52 guide the movement of trigger 108.

The trigger 50 stops when it impacts the shoe 52, and the leg 78 and shock absorber 102 may flex, for example, compress resiliently, to gradually slow its movement 108. The length of the leg 78 and the Shock absorber thickness 102 can be selected with a desired degree of resilience in mind. The longer the leg 78, the more the material tensions and acts as a spring, gradually reducing the movement of the trigger 108. Similarly, a thicker shock absorber 102 may tend to slow the movement of the trigger 50. gradually, that is, it slows down. Components can also dissipate impact energy, for example by damping the impact and converting the kinetic energy into heat or sound.

When trigger 50 is recessed, in this embodiment, fluid 25 flows through inlet passage 56, between the seat surface 62 and contact surface 82 of trigger 50, and outwardly through outlet passage 68. Fluid it continues to flow until the pressure on each side of trigger 50 equalizes to some degree determined in part by the resistance and separation of magnets 72 and 98.

When the pressure in the inlet passage 56 and the inlet

output 68 equalizes, or is reduced below some threshold, magnets 72 and 98 return trigger 50 to their original position. At this time, the trigger 50 moves backward through the trigger container 64 away from the shoe 52 as indicated by the arrow 110. The trigger 50 continues to move until the contact surface 82 of the head 76 reaches the surface. When they contact, the seat surface 62 and 5 the contact surface 82 seal the inlet passage 56 of the outlet passage 68. In some embodiments, magnets 72 and 98 tilt the trigger. 50 against the seating surface 62.

Once returned, the trigger 50 remains in contact with the seat surface 62 until the pressure in the inlet passage 65 rises again, at which point the cycle described above repeats.

Advantageously, certain characteristics of trigger 50 are designed to reduce the magnitude of their inertial forces by decreasing the deceleration of trigger 50. Some components may gradually slow down trigger 50 when it impacts shoe 52. For example, love Shock weaver 102 may resiliently compress during an impact, and extend the length of time during which trigger 50 is brought to a halt. As a result, because deceleration is reduced, the resulting forces, and tensions within trigger 50, may be reduced. Leg 78 may also resiliently compress and reduce deceleration. For this purpose, the length of the leg 88 may be relatively long to accentuate the stress (e.g., non-plastic deformation) within the body 70. Therefore, even if the material in the body 70 has a relatively high Young modulus, Long leg 78 can still act as a spring to some degree. This reduction in acceleration reduces the forces applied 25 to trigger 50, which may tend to limit fatigue and prolong the life of trigger 50.

As mentioned, trigger body 70 is injection molded around magnet 72. For certain types of magnets, this can cause problems. The injection molding process can expose the magnet to 30 high temperatures, which can degrade the field strength of the magnet. The injection molding process can result in high stress development near structurally critical areas of the trigger. However, this problem can be alleviated by the embodiment described below, which attaches the magnet to the trigger with a mounting member.

Fig. 6 illustrates another embodiment of a trigger 112. In this embodiment, trigger 112 includes the previously described features of trigger 50, except that in this embodiment, magnet 72 is mounted to body 70 by a mounting member 114 , which can be made of metal, high strength plastic, or other suitable materials. Mounting member 114 transfers forces from magnet 72 to body 70. In various embodiments, mounting member 114 can either be arranged between the two as an intermediate member, or interconnect the two in some other manner. - neira.

Mounting member 114 includes a number of cooperating features for holding magnet 72. In this embodiment, mounting member 114 has a downstream contention 116 and a downstream contention 118 which overlap on opposite sides of magnet 72 to holding magnet 72. In addition, mounting member 114 couples to magnet 72 along its sides with a layer of adhesive 120. Threads 122 on the outer sides of mounting member 114 interface with complementary threads 124 on internal volume 86 of trigger 112. The threads 124 20 may extend along a portion of the leg 78.

Figures 7 and 8 illustrate exploded views of trigger 112 from different perspectives. In this embodiment, downstream contention 118 includes one or more plastic deformable members that are folded over magnet 72 after magnet 72 is inserted into mounting member 25. Other embodiments may not include downstream contention 118 and may, instead, use an adhesive layer 120 and / or body 70 to contain the magnet 72 on the upstream side of the mounting member 114.

For mounting trigger 112, first body 70 and mounting member 114 are independently formed. Trigger body 70 may be injection molded in a process similar to the process described above, and mounting member 114 may be formed of plastic, metal or other suitable materials by casting, injection molding, forging, welding, machining, or a combination of them. In some embodiments, the trigger body 70 may be injection molded around the mounting member 114 prior to inserting the magnet into the mounting member 114. In some embodiments, the orientation of the mounting member 114 is reversed, and the downstream side of mounting member 114 includes deformable members 118.

Once these components are formed, they can be assembled as follows. An adhesive layer 120 may be applied within the mounting member 114 (as noted, however, some embodiments may not include the adhesive layer 120), and the magnet 72 is inserted into the mounting member 114. After the magnet 72 is inserted, the downstream containment 118 may be folded over the magnet 72 as indicated by the arrows 128. Then, the mounting member 114, with magnet 72 inside, is placed in the internal volume 86 of the magnet. trigger body 70, and a tool rotates mounting member 114, applying torque to the tool interface 126. As mounting member 114 rotates, it engages complementary thread 124, thereby holding magnet 72 in body 70 of the trigger 112.

Advantageously, in some embodiments, the body 70 of the

112 may be formed without exposing the magnet 72 to high temperatures during the injection molding process. In the illustrated embodiment, the magnet 72 is introduced into the trigger body 70 after being injection molded. Accordingly, the magnet 72 avoids the heat of the injection molding process. Avoidance of such high temperatures is envisioned to protect magnet 72 from heat degradation, thereby potentially avoiding a processing step to re-magnetize the magnet. Forming body 70, in the absence of magnet 72 may also avoid different thermal expansion voltages on magnet 72 and body 70.

In addition, some modalities may reduce stresses.

As mentioned above, the mass of the magnet 72 is relatively large compared to the mass of the body 70. During an impact, the inertial forces of the magnet 72 can apply substantial loads to the body 70. magnet 72 is decelerated, threads 122 and 124 may distribute the inertia load over an area of body 70, thus potentially reducing stress concentrations at any point within body 70. Reducing these stress concentrations is thought to extend life trigger 112 through fatigue reduction.

Other embodiments may include other types of mounting members. For example, some embodiments may include an elastically deformable mounting member 10 with one or more grooves along its sides. To insert the magnet 72, the mounting member may be deformed then the slot is wider, and the magnet 72 may be placed within the deformed mounting member. Then the mounting member relaxes around the magnet 72 and the assembly may be attached to the body 70.

Figure 9 illustrates another example of a valve 44 which may include one or more of the triggers or other valve members described above. The illustrated valve 44 includes a seat 46, a protector 48, a plurality of triggers 50, and a plurality of shoes 52. In this embodiment, each trigger 50 and corresponding shoe 52 are housed by the seat 46 and protector 48, which they limit each other and have a generally circular, cylindrical shape. These components are described below in more detail below.

In this embodiment, seat 46 includes a cylindrical lip 54 and 25 a plurality of inlet passages 56 in a hexagonal packaging arrangement. The illustrated inlet passages 56 define generally circular, cylindrical volumes which are concentric about respective axes 57. These axes 57 are generally parallel to one another in a central axis 58 of valve 44. An upstream portion of The inlet 56 includes a concentric radius 60, and a downstream portion includes a beveled concentric seating surface 62. Other embodiments may include inlet passages 56 with different conformations, arrangements, or orientations.

In Figure 9, the downstream side of the seat 46 seals against the protector 48, which in this embodiment includes a plurality of trigger containers 64, fluid drainage openings 66, and outlet passages 68. The 5 containers of trigger 64 are generally circular, cylindrical volumes that are also concentric about their respective axes 57. Trigger containers 64 are sized to coincide with trigger 50 so that trigger 50 can travel within trigger container 64 along of a generally linear path. Accordingly, such triggers 5010 may be characterized as having a unique degree of freedom which, as an example, in this embodiment is their position along axis 57. Other embodiments may have additional degrees of freedom, which correspond to different types of movement.

Fluid drain openings 66 are arranged under the shoe 52 and are in fluid communication with a volume 86 (Figure 5) between the trigger 50 and the shoe 52. The illustrated outlet passages 68 are generally parallel to one another and to the inlets 56. In this embodiment, the outlets 68 are disposed off-axis of the inlets 56, in addition to the triggers 50, and extend through the shield 48 to their downstream side. Other embodiments may not include trigger containers 64. In some embodiments, shoe 52 may guide the movement of trigger 50. It should also be appreciated that some guards 48 may not include fluid drain openings 66 which They should not be construed to suggest that any other features discussed here may not be omitted either.

The various valves described above may be employed in a variety of fluid handling systems, including fluid compressors. An exemplary compressor 210 is provided in Figure 10. In the presently illustrated fashion, compressor 210 includes a pair of compression rollers 212 coupled to a frame 214. As discussed in more detail below, a variety of internal components may be arranged. inside cylinders 212 and frame 214 to enable fluid compression within cylinders 212. In one embodiment, compressor 210 may be used to compress natural gas. However, in other embodiments, compressor 210 may be configured and / or used to compress other fluids. A mechanical power source or driver 216, such as a motor or an electric motor, may be coupled to compressor 210 to provide mechanical power to the various internal components and enable fluid compression within the cylinders 212. To facilitate access to such Internal components, as may be desired for diagnostic or maintenance purposes, openings in frame 214 and 10 may be provided selectively accessed via removable covers disposed over the openings.

In addition, exemplary cylinders 212 include capped recesses 218 configured to receive valve assemblies, such as valve assembly 220. Valve assembly 220 may include one or more of the various valve embodiments discussed above. While only a single valve assembly 220 is illustrated, it will be appreciated that, in various embodiments, additional valve assemblies are included within some or all other capped recesses 218. It will also be appreciated that cylinders 212 may include conduit conduits. internal fluids between recesses 218 and valve assemblies 220 to facilitate the flow of a fluid into and out of cylinders 212 through such valve assemblies. In addition, the installation of various components such as cages or fasteners may be employed to facilitate mounting of valve assemblies 220 within recesses 218.

Although the exemplary compressor 210 is illustrated as a

dual discharge reciprocating compressor, other compressor configurations may also employ and benefit from the techniques disclosed herein. For example, in other embodiments, compressor 210 may include a different number of cylinder discharges, such as a four-discharge compressor, a six-discharge compressor, a freely coupled reciprocating compressor, a screw compressor, or the like. . In addition, other variations are also envisioned, including variations in stroke duration, operating speed, and size, to name but a few.

A cross-sectional view of exemplary compressor 210 is provided in Fig. 11, which illustrates a number of exemplary internal components 5 of the compressor of Fig. 10. In the presently illustrated embodiment, frame 214 of exemplary compressor 210 includes a central hollow body. 222 which generally defines an internal volume 224 at which various internal components may be received, such as a crankshaft 226. In one embodiment, the central member 222 may have a generally curved or cylindrical conformation. It should be noted, however, that the central body 222 may have other conformations or configurations in complete accordance with the present techniques.

In operation, driver 216 rotates crankshaft 226 supported within the internal volume 224 of frame 214. In one embodiment, crankshaft 226 is coupled to crosspieces 230 via connecting rods 228 and pins 232. Crossheads 230 are disposed within crosshead guides 234, which generally extend from central body 222 and facilitate the connection of cylinders 212 to compressor 210. In one embodiment, compressor 210 includes two generally perpendicular crosshead guides 234. 20, opposite sides of the central housing or housing 222, although other configurations are also provided. As may be appreciated, the rotational motion of crankshaft 226 is translated via connecting rods 228 for alternate linear motion 230 within crosshead guides 234.

As mentioned above, cylinders 212 are configured for

to receive a fluid for compression. The crosspieces 232 are coupled to pistons 236 disposed within the cylinders 212, and the alternative movement of the crosspieces allows liquid compression within the cylinders 212 via the pistons 236. Particularly, as piston 236 is driven forward (or if 30, toward the outside of central body 222) for cylinder 212, piston 236 forces fluid within the cylinder to a smaller volume, thereby increasing fluid pressure. The discharge valve, such as a valve assembly 220, may then open to allow pressurized or compressed fluid to escape from cylinder 212. Piston 236 may then move backwards, and additional fluid may enter the cylinder 212 through an inlet valve, which may also comprise compression valve assembly 220, in the same manner as described above. In addition, as will be appreciated, cylinders 212 may be configured to facilitate fluid compression in both forward and backward piston paths 236. For example, as piston 236 advances in the manner discussed above to compress fluid into On one side of the piston, additional fluid may be introduced into the cylinder on the opposite side of the piston. Such fluid would then be compressed in the backward path of piston 236.

While the invention may be susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and have been described in detail herein. However, it should be understood that the invention is not intended to be limited to the particular forms described. Preferably, the invention is to cover all modifications, equivalences, and alternatives that are within the spirit and scope of the invention as defined by the following appended claims.

Claims (26)

A fluid manipulation system comprising: a trigger comprising: a body; a magnet; and a mounting member configured to secure the magnet to the body. The system of claim 1, wherein the body comprises: a head having a sealing surface configured to seal against a seating surface; and a leg extending from one side downstream of the head. The system of claim 2, wherein the leg has a generally tubular conformation defining an internal volume in which both the magnet and the mounting member are disposed. The system of claim 2, wherein the sealing surface defines a generally truncated cone volume. The system of claim 1, wherein the mounting member comprises an elastically deformable member configured to hold the magnet to the body. The system of claim 1, wherein the mounting member comprises threads configured to hold the mounting member to the body. The system of claim 1, wherein the mounting member comprises a plastic deformable member configured to hold the magnet to the mounting member. The system of claim 1, comprising an adhesive disposed between the magnet and the mounting member. The system of claim 1, wherein: the body is a one-piece body made of a material including plastic, and wherein the body includes both a head with a sealing surface and a tubular leg extending from one another. a downstream side of the head, wherein both the head and tubular leg are rotationally symmetrical about the same axis; the mounting member includes metal and comprises: a plurality of plastic deformable members extending from one side upstream of the mounting member; a generally tubular, circular sidewall with external threads configured to secure the mounting member to complementary threads disposed within a tubular portion of the head; and a downstream contention having a tool interface configured to receive torque from a tool; and the magnet is disposed within the circular tubular side wall of the mounting member between the plurality of plastic deformable members and the downstream containment. A system according to claim 1, comprising: a seat having an inlet passage with a seating surface, wherein the seat is arranged upstream of the trigger; a shoe disposed downstream of the trigger and having a repulsion magnet; a support having a container in which the shoe is arranged and an outlet passage. The system of claim 10, wherein the shoe comprises a shock absorber. The system of claim 10, wherein the shoe, the repulsion magnet, and the protector have a liquid drainage opening. The system of claim 10, comprising a compressor having a compression cylinder in fluid communication with the inlet passage and a driver coupled to a piston disposed within the compression cylinder. A valve, comprising: a trigger, comprising: a magnet; and a body disposed around the magnet, wherein the body includes a head and a leg defining a distal surface that is downstream of the magnet. A valve according to claim 14, wherein a downstream side of the magnet is substantially larger than an upstream side of the magnet. A valve according to claim 14, wherein the leg defines an internal volume generally in a truncated cone. Valve according to claim 14, comprising a shoulder arranged adjacent a downstream side of the magnet. A valve according to claim 17, wherein the shoulder includes a fillet on a downstream side of the shoulder, where the shoulder meets the leg. 19. Method of forming a valve, the method comprising: providing a trigger body for a valve; provide a magnet; provide a mounting member configured to attach the magnet to the trigger body. The method of claim 19, wherein providing the trigger body comprises injection molding of the trigger body. The method of claim 19, comprising: inserting the magnet into the mounting member; and after inserting the magnet, attach the mounting member to the trigger body. The method of claim 21, wherein attaching the mounting member to the trigger body comprises engaging threads in the trigger body with complementary threads on the mounting member. 23. Apparatus comprising: a compressor; and a valve disposed between a fluid inlet and a fluid outlet of the compressor, wherein the valve comprises: a valve member; a mounting member coupled to the valve member; and a magnet coupled to the valve member by the mounting member. Apparatus according to claim 23, wherein the compressor comprises a piston. Apparatus according to claim 23, wherein the valve member comprises a trigger. Apparatus according to claim 25, wherein the trigger comprises a leg, and wherein the mounting member is disposed between the magnet and the leg.