Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16K—VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING
  • F16K1/00—Lift valves or globe valves, i.e. cut-off apparatus with closure members having at least a component of their opening and closing motion perpendicular to the closing faces
  • F16K1/32—Details
  • F16K1/34—Cutting-off parts, e.g. valve members, seats
  • F16K1/44—Details of seats or valve members of double-seat valves
  • F16K1/443—Details of seats or valve members of double-seat valves the seats being in series
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16K—VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING
  • F16K1/00—Lift valves or globe valves, i.e. cut-off apparatus with closure members having at least a component of their opening and closing motion perpendicular to the closing faces
  • F16K1/30—Lift valves or globe valves, i.e. cut-off apparatus with closure members having at least a component of their opening and closing motion perpendicular to the closing faces specially adapted for pressure containers
  • F16K1/301—Lift valves or globe valves, i.e. cut-off apparatus with closure members having at least a component of their opening and closing motion perpendicular to the closing faces specially adapted for pressure containers only shut-off valves, i.e. valves without additional means
  • F16K1/303—Lift valves or globe valves, i.e. cut-off apparatus with closure members having at least a component of their opening and closing motion perpendicular to the closing faces specially adapted for pressure containers only shut-off valves, i.e. valves without additional means with a valve member, e.g. stem or shaft, passing through the seat
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16K—VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING
  • F16K1/00—Lift valves or globe valves, i.e. cut-off apparatus with closure members having at least a component of their opening and closing motion perpendicular to the closing faces
  • F16K1/32—Details
  • F16K1/34—Cutting-off parts, e.g. valve members, seats
  • F16K1/46—Attachment of sealing rings
  • F16K1/465—Attachment of sealing rings to the valve seats

Definitions

• the invention relates to a gas charging valve, in particular carbon dioxide, more particularly comprising a seat pierced with a conduit, a pin movable inside the conduit against the compression of a return spring resting on the seat and an elastomeric gasket compressed between the seat and the spindle to close the duct when the spindle is moved to a first closed position, called low pressure.
• Such a charge valve is known from US 6,637,726 with respect to a CO 2 carbon dioxide air conditioning system.
• the elastomer seal In the closed position at low pressure, that is to say for gas pressures up to 60 bar, the elastomer seal is sufficient to seal the conduit. But the stress on the spindle increases with an increase in gas pressure, up to 200 bar. There is then a gradual decrease in the tightness of the closure of the conduit, the elastomer seal becoming more permeable, especially at high temperatures, for example up to 180 degrees Celsius ( 0 C).
• the object of the invention is to modify a charging valve of the type recalled above to ensure a tight seal of the conduit not only at low pressure but also at high pressure.
• the subject of the invention is a gas charging valve, in particular of carbon dioxide, comprising a seat pierced with a duct, a spindle movable inside the duct against the compression of a return spring in pressing on the seat and a compressed elastomer seal between the seat and the spindle to close the duct when the spindle is moved to a first closed position, said low pressure, characterized in that a thermoplastic seal is attached to the seat or on the spindle for closing the conduit when the thermoplastic seal is compressed between the seat and the spindle in a second, so-called high-pressure, closing position against further compression of the elastomeric seal.
• thermoplastic seal Under the effect of an increase in the pressure of the gas exerted on the spindle, the thermoplastic seal is gradually compressed between the seat and the metal pin. This results in a deformation of the thermoplastic seal to ensure a tight contact with both the seat and the spindle. This arrangement ensures a sealed closure of the conduit in the high pressure closed position.
• the former advantageously makes it possible to limit the additional compression of the second by avoiding a detrimental crush.
• thermoplastic seal is a polyetheretherketone seal to advantageously maintain a good mechanical strength in a temperature range up to 250 0 C.
• the elastomeric seal When the elastomeric seal is in contact with a gaseous medium formed of molecules of very small dimensions, such as those of carbon dioxide, the latter will migrate into the material of the elastomeric seal and cause its swelling. This swelling results in a risk of displacement of the elastomeric seal out of its seat between the seat and the spindle, or a risk of tearing if it is mounted too tight in its housing. The swelling of the elastomeric seal may even result in a risk of loosening the thermoplastic seal reported on the seat or on the spindle. This could result in a decrease in the seal, both at the elastomeric seal and at the thermoplastic seal.
• a gaseous medium formed of molecules of very small dimensions, such as those of carbon dioxide
• Another phenomenon may occur at the moment of opening of the mechanism when the container is under pressure. Indeed, the depression that occurs at the time of opening of the mechanism can also cause a displacement of the elastomeric seal out of its reserved space.
• thermoplastic seal attached to the seat or on the spindle is provided with protruding retaining means for retaining the compressed elastomer seal between the seat and the spindle while providing a gap between the thermoplastic seal and the elastomeric seal allowing the latter to swell in the presence of gas.
• the elastomeric seal is held when compressed between the seat and the spindle, the protuberance of these means causing a free volume or gap between the elastomer seal and the seal thermoplastic which can be advantageously used during the swelling of the elastomeric seal in the presence of gas, in particular carbon dioxide.
• FIGS. 1a and 1b show a sectional view of a gas charging valve according to a first embodiment of the invention, respectively in the closed position at low and at high pressure and in which the elastomer seal is integral with the seat.
• FIGS. 2a and 2b show in section a gas charging valve according to a second embodiment of the invention, in the closed position at low and high pressure respectively, and in which the elastomer seal is secured to the seat and held by protruding retaining means formed on the thermoplastic seal and on the seat.
• Figure 2c is an enlargement of Figure 2b.
• FIGS. 3a and 3b show in section a gas charging valve according to a third embodiment of the invention, respectively in the closed position at low and at high pressure and in which the elastomer seal is secured to the spindle and maintained by protruding retaining means formed on the thermoplastic seal and on the spindle.
• Figure 3c is an enlargement of Figure 3b.
• Figure 4a shows in section a gas charging valve according to a fourth embodiment of the invention in a high pressure closed position and wherein the thermoplastic seal is provided with a lip.
• Figure 4b is an enlargement of Figure 4a.
• a gas charging valve comprises a seat 1 pierced with a duct 3 and a spindle 5 movable inside the duct 3 against the compression of a return spring 7 in support in the seat 1.
• the pin 5 is moved from an open position to a first closed position, called low pressure, of the duct 3 where an elastomer seal 9 is respectively separated from the pin to release its passage, or compressed in sealing contact between the pin 5 and the seat 1 to obstruct the conduit.
• the mechanism is intended to be mounted in a valve body, not shown in the figures, being for example screwed with a thread 13 formed on the seat 1.
• a second elastomer seal 15 seals between the seat and the valve body. The compression of the second elastomeric seal 15 is determined by the tightening force of the thread 13 in the valve body.
• the valve body is then mounted on the wall of a given system, for example a pipe forming part of a CO 2 carbon dioxide air conditioning system.
• the pressure that prevails in the pipe filled with carbon dioxide is likely to vary from low to high pressures, typically from 0 to 160 bar, especially under the effect of an increase in temperature.
• thermoplastic seal January 1 is attached to the seat 1 or the pin 5 to close the duct 3 when the thermoplastic seal 1 1 is compressed between the seat 1 and the pin 5 in a second closed position, called at high pressure, against further compression of the elastomer seal 9.
• thermoplastic seal 11 is secured to the seat 1 in a housing 12.
• thermoplastic seal 11 is attached to one end of the pin 5 having passed around a restriction 14 of the pin 5.
• thermoplastic seal 1 1 deforms in compression between the seat 1 and the pin 3 to come into sealed contact in the second closed position of the duct 3, said closure at high pressure.
• the second closed position is reached when the pin 5 is moved from the first closed position, called low pressure, against the additional compression of the elastomer seal 9.
• thermoplastic seal 11 The deformation of the thermoplastic seal 11 is more particularly illustrated by the enlarged figures 2c and 3c.
• Tests carried out with a thermoplastic polyetheretherketone seal that is not loaded with glass fibers show that the gas charging valve, for example carbon dioxide, is tight less than one gram per year for a gas pressure of up to 130 bars with a temperature of 130 ° C.
• the segment forming the thermoplastic seal 11 is made of a metal alloy, for example the the same alloy as that of the seat and the spindle, the tightness of the gas charge valve thus obtained drops to 5 grams per year or more.
• the thermoplastic seal 11 of a gas charge valve according to the invention serves as a seal and not just a mechanical stop limiting additional compression of the elastomeric seal.
• FIGS. 2a to 2c illustrate a second embodiment of the present invention in which the elastomeric seal 9 is held by retaining means 10a and 10b.
• these retaining means consist of a ring, in this case an upper ring 10a formed protruding on a face 18 of the housing 12 of the seat 1 and a crown lower part 10b formed protruding on a face 16 of the thermoplastic seal 11.
• This arrangement creates a gap 8a between the elastomer seal 9 and the seat 1 which allows the elastomer seal 9 to inflate without exerting on the thermoplastic seal 11 a pressure which could reduce the sealing of the closed position at high pressure.
• the elastomer seal 9 is held by retaining rings 10a and 10b formed protruding respectively on a face 19 of the pin 5 and on the face 16 of the thermoplastic seal 11. arrangement creates a gap 8a between the elastomer seal 9 and the pin 5 and a gap 8b between the elastomer seal 9 and the thermoplastic seal 11. These two interstices 8a and 8b allow the elastomer seal 9 to inflate without exerting on the thermoplastic seal 11 a pressure that could reduce the tightness of the high-pressure closure position, or to remove it from the spindle 5. Such swelling of the elastomer seal is caused by the migration of carbon dioxide in the elastomeric seal and by the temperature increase in use of the gas charge valve.
• the interstices 8a and 8b form a volume or free space not occupied by the elastomeric seal 9 when the latter is not yet compressed or inflated by the gas. Thanks to this space, a swelling of the elastomer anointed 9 in the cavity created by the interstices 8a and 8b is made possible during the operation of the valve without risk of tearing of this elastomeric seal or detachment of the thermoplastic seal 11.
• the retaining means 10a and 10b improve the maintenance of the elastomer seal 9 between the seat 1 and the spindle 5.
• the elastomer seal 9 is locally held by gripping between the two retaining means 10a and 10b while preserving a free volume created by the interstices 8a and 8b for the swelling of the elastomer seal.
• the configuration of the retaining means 10 in the cavity 8 will make it possible to minimize the leakage rate of the valve.
• thermoplastic seal 11 has a lip 21 to better ensure this sealing contact with the seat 1 by deformation of the lip 21, in particular with a frustoconical segment 17 of the duct 3. In the case where the thermoplastic seal 11 is integral with the seat 1, the lip 21 is deformed to better ensure the sealing contact against the pin 5.
• the thermoplastic seal 11 is preferably cylindrical in shape. However, it is also planned to design a frustoconical thermoplastic seal to come into sealing contact with a cylindrical segment of the seat 1 or the spindle 5. In each of the embodiments of the invention, the contact by deformation of the thermoplastic seal 11 against the seat 1 and the spindle 5, within the duct 3, makes it possible to maintain the tightness of the gas charging valve according to the invention, despite the increase in gas pressure, by a displacement of the spindle of the closed position at low pressure at the high pressure closed position against the additional compression of the elastomeric seal 9.
• the terms “rigid” and “flexible” mean that the thermoplastic seal 11 deforms less than the elastomer seal 9.
• the mechanism according to the invention is simple in its design since it does not require mechanical intervention after installation of the valve on the tubing of the air conditioning system used.

Landscapes

• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Lift Valve (AREA)
• Filling Or Discharging Of Gas Storage Vessels (AREA)
• Check Valves (AREA)

Applications Claiming Priority (2)

Publications (1)

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ID=37054652

Family Applications (1)

Country Status (6)

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• 2006
  • 2006-01-17 FR FR0600410A patent/FR2896293B1/fr active Active
• 2007
  • 2007-01-11 US US12/160,810 patent/US8087642B2/en active Active
  • 2007-01-17 CN CNA2007800024841A patent/CN101371066A/zh active Pending
  • 2007-01-17 WO PCT/EP2007/000379 patent/WO2007082729A1/fr active Application Filing
  • 2007-01-17 JP JP2008550679A patent/JP2009523975A/ja active Pending
  • 2007-01-17 EP EP07702833A patent/EP1974160A1/fr not_active Withdrawn

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