CA1098411A - Divers exhaust valve - Google Patents
Divers exhaust valveInfo
- Publication number
- CA1098411A CA1098411A CA273,370A CA273370A CA1098411A CA 1098411 A CA1098411 A CA 1098411A CA 273370 A CA273370 A CA 273370A CA 1098411 A CA1098411 A CA 1098411A
- Authority
- CA
- Canada
- Prior art keywords
- valve
- exhaust
- gas
- inlet
- pressure
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
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- Self-Closing Valves And Venting Or Aerating Valves (AREA)
Abstract
ABSTRACT
The invention provides an exhaust valve comprising a valve body, an inlet duct in the valve body for receiving gas to be exhausted through the valve, an exhaust duct in the valve body for exhausting the said gas from the valve, and a valve member subject on the one hand to the ambient external pressure and on the other hand to the pressures in the inlet and exhaust ducts, the valve member moving according to changes in the said pressures between an open position in which there is communication between inlet and exhaust ducts for the exhaustion of gas through the valve and a closed position in which it cuts off such communication; the valve member is preferably mounted in a diaphragm. It also provides a similar valve in which the valve member is instead subject on said one hand to a predetermined maintained fluid pressure, e.g. that within a pressurized chamber. The latter valve can be used to control the pressure in an exhaust line from the exhaust valve. One or both valves can be used in a system for recovering for reuse helium employed in breathing mixtures for deep dives.
The invention provides an exhaust valve comprising a valve body, an inlet duct in the valve body for receiving gas to be exhausted through the valve, an exhaust duct in the valve body for exhausting the said gas from the valve, and a valve member subject on the one hand to the ambient external pressure and on the other hand to the pressures in the inlet and exhaust ducts, the valve member moving according to changes in the said pressures between an open position in which there is communication between inlet and exhaust ducts for the exhaustion of gas through the valve and a closed position in which it cuts off such communication; the valve member is preferably mounted in a diaphragm. It also provides a similar valve in which the valve member is instead subject on said one hand to a predetermined maintained fluid pressure, e.g. that within a pressurized chamber. The latter valve can be used to control the pressure in an exhaust line from the exhaust valve. One or both valves can be used in a system for recovering for reuse helium employed in breathing mixtures for deep dives.
Description
This invention relates to an exhaust valve for exhausting gases used underwater, e.g. exhalations by a diver, fouled or used gas from a diving bell or submersible vessel or underwater installation, and provides an exhaust valve comprising a valve S body, an inlet duct in the valve body for receiving gas to be exhausted through the valve, an exhaust duct in the valve body for exhausting the said gas from the valve, and two valve members, each valve member being subject on the one hand to the ambient external pressure and on the other hand to the pressures in the inlet and exhaust ducts, and both valve members moving according to changes in the said pressures between an open position in which there is communication between inlet and exhaust ducts for the exhaustion of gas through the valve and a closed position in which it cuts off such communication.
When, for example, the exhaust valve is in operation in conjunction with a diver's helmet or mask, the inlet duct will communicate with the interior of the diver's helmet or mask and so be at about the same pressure as the external water and the outlet of the exhaust duct can communicate with a line from which the exhaust gases can be collected. With the valve members in the closed position, the pressure in the exhaust duct will be lower than that in the inlet duct, and these pressures and the dimensions of the ducts and valve members will be such that the external ambient pressure (i.e. the water pressure) maintains the valve members in the closed position until sufficient counter-pressure is generated (e.g. ky~the diver exhaling) to move the valve members temporarily to the open position with consequent exhaustion of the excess (e.g. exhaled) gases via the low pressure exhaust duct; on exhaustion of the gases, the water pressure returns the valve C
When, for example, the exhaust valve is in operation in conjunction with a diver's helmet or mask, the inlet duct will communicate with the interior of the diver's helmet or mask and so be at about the same pressure as the external water and the outlet of the exhaust duct can communicate with a line from which the exhaust gases can be collected. With the valve members in the closed position, the pressure in the exhaust duct will be lower than that in the inlet duct, and these pressures and the dimensions of the ducts and valve members will be such that the external ambient pressure (i.e. the water pressure) maintains the valve members in the closed position until sufficient counter-pressure is generated (e.g. ky~the diver exhaling) to move the valve members temporarily to the open position with consequent exhaustion of the excess (e.g. exhaled) gases via the low pressure exhaust duct; on exhaustion of the gases, the water pressure returns the valve C
- 2 -members to the closed position. The exhaust valve will operate correspondingly when used in a corresponding manner for exhaustion of used gas from a bell or other submerged unit~ craft or installation.
It will be evident that the principle of the invention, balancing inlet and exhaust line pressure against external water pressure so that exhalation or other build-up of exhaust pressure opens the valve for exhaustion of gases, can be put in operation in a number of ways. The valve body may have a plurality of inlet ducts, and inlet and outlet ducts may be arranged relative to one another in a variety of different ways. The movable valve members are conveniently in diaphragm form, but this is not essential.
The arrangement and dimensions of the inlet and exhaust ducts and valve members will be chosen to provide opening of the valve at the appropriate excess inlet duct pressure (over external pressure).
In operation the required inlet duct pressure excess can be controlled by a pressure release valve controlling the pressure in the exhaust line. The exhaust valve will of course open to relieve any excess pressure on the inlet side te.g. in the diver's helmet), whether due to admission of excess fresh gas or to generation of exhaust or exhaled gas.
It can be of practical advantage for one of the said two valve members to be more readily openable than the other, due e.g.
at least in part to difference in exhaust orifice sizes.
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The mentioned pressure release valve, preferably provided in or at the end of an exhaust line communicating with the exhaust duct of the exhaust valve, can be of conventional type but is preferably essentially according to the above defini-tion for the exhaust valve except that the valve member (preferably mounted in a diaphragm~ is sub~ect on the one hand not to the ambient extërnal pressure but to a predetermined fluid pressure maintained (e.g. in a closed chamber of -which the valve member can form a wall portion) at the value required for the equilibrium pressure in the exhaust line, this predetermined pressure preferably being adjustable; the valve member will thus normally close communication between the release valve inlet duct ~communicating with the said exhaust line) and its own outlet or exhaust duct until the exhaust line pressure is increased by exhaustion of gas thereinto from the exhaust valve.
Exhaust valves according to the invention can be used in a diving gas recovery system in which exhaust gas, e.g. from a diver is collected, scrubbed and recompressed for further use. The main interest here is in recovering heli~m used in helium~oxygen breathing mixtures for deep dives. One such system according to the invention comprises a diver's helmet having an inlet connectable to a supply of pressurised breathing gas mixture and an exhaust valve as defined above for the -exhaustion of exhaled gas, the exhaust valve being connectable externally to one end of an exhaust tube; and a recycle module having a pressure release valve (e.g. as described above) having its inlet connectable to another end of such an exhaust tube and its outlet communicating with a tube connectable to a c~mpressor intake, a high pressure tube connectable to the compressor outlet for conveying compressed gas to a high pressure .
': ' :'~; ' -~8~
storage bank, and at least one scrubber unit for removing CO2 from the collected gas before and/or after compression. In practice the system will normally be applied to a diver operating from a chamber, e.g. a bell or submersible, and the exhaust tube from the helmet outlet valve will preferably have a first section extending to a manifold in the chamber, and a second section extending from the manifold to the pressure release valve, the bell manifold preferably having a trap for condensed liquids. Provision may also be made for exhausting the chamber atmosphere, when the chamber is depressurised, through the said or another pressure release valve into the low pressure side of the module for scrubbing, recompression, and recycle to storage for re-use.
Embodiments of valves for use in the invention will now be described by way of example only, with reference to the accompanying drawings, in which:
Figure 1 is a side elevation view, partly in section, of one exhaust valve;
Figure 2 is a section along the lines 2-2 of Figure l;
Figure 3 is a side elevation view, partly in section, of another exhaust valve;
Figure 4 is a side elevation view, partly in section of a third exhaust valve;
Figure 5 is a side elevation view, partly in section, of a fourth valve;
Figure 6 is a section along lines 6-6 of Figure 5;
Figure 7 is a plan view, with parts broken away, of a valve according to the inve~ltion;
Figure 8 is a vertical section through the valve of Figure 7; and 4~1 .
Fi~re 9 is an elevation view, in section, of a pressure release valve according to the invention for controlling gas $10w Erom an e~haust line connected to an exhaust valve according to the invention.
In the drawings, like features are lndicated by like reference numerals. t?
The valve illustrated in Figures 1 and 2 has a valve body 2;
~--an e~haust duct 4 extends axially through the valve body from one face
It will be evident that the principle of the invention, balancing inlet and exhaust line pressure against external water pressure so that exhalation or other build-up of exhaust pressure opens the valve for exhaustion of gases, can be put in operation in a number of ways. The valve body may have a plurality of inlet ducts, and inlet and outlet ducts may be arranged relative to one another in a variety of different ways. The movable valve members are conveniently in diaphragm form, but this is not essential.
The arrangement and dimensions of the inlet and exhaust ducts and valve members will be chosen to provide opening of the valve at the appropriate excess inlet duct pressure (over external pressure).
In operation the required inlet duct pressure excess can be controlled by a pressure release valve controlling the pressure in the exhaust line. The exhaust valve will of course open to relieve any excess pressure on the inlet side te.g. in the diver's helmet), whether due to admission of excess fresh gas or to generation of exhaust or exhaled gas.
It can be of practical advantage for one of the said two valve members to be more readily openable than the other, due e.g.
at least in part to difference in exhaust orifice sizes.
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. ::
., :
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The mentioned pressure release valve, preferably provided in or at the end of an exhaust line communicating with the exhaust duct of the exhaust valve, can be of conventional type but is preferably essentially according to the above defini-tion for the exhaust valve except that the valve member (preferably mounted in a diaphragm~ is sub~ect on the one hand not to the ambient extërnal pressure but to a predetermined fluid pressure maintained (e.g. in a closed chamber of -which the valve member can form a wall portion) at the value required for the equilibrium pressure in the exhaust line, this predetermined pressure preferably being adjustable; the valve member will thus normally close communication between the release valve inlet duct ~communicating with the said exhaust line) and its own outlet or exhaust duct until the exhaust line pressure is increased by exhaustion of gas thereinto from the exhaust valve.
Exhaust valves according to the invention can be used in a diving gas recovery system in which exhaust gas, e.g. from a diver is collected, scrubbed and recompressed for further use. The main interest here is in recovering heli~m used in helium~oxygen breathing mixtures for deep dives. One such system according to the invention comprises a diver's helmet having an inlet connectable to a supply of pressurised breathing gas mixture and an exhaust valve as defined above for the -exhaustion of exhaled gas, the exhaust valve being connectable externally to one end of an exhaust tube; and a recycle module having a pressure release valve (e.g. as described above) having its inlet connectable to another end of such an exhaust tube and its outlet communicating with a tube connectable to a c~mpressor intake, a high pressure tube connectable to the compressor outlet for conveying compressed gas to a high pressure .
': ' :'~; ' -~8~
storage bank, and at least one scrubber unit for removing CO2 from the collected gas before and/or after compression. In practice the system will normally be applied to a diver operating from a chamber, e.g. a bell or submersible, and the exhaust tube from the helmet outlet valve will preferably have a first section extending to a manifold in the chamber, and a second section extending from the manifold to the pressure release valve, the bell manifold preferably having a trap for condensed liquids. Provision may also be made for exhausting the chamber atmosphere, when the chamber is depressurised, through the said or another pressure release valve into the low pressure side of the module for scrubbing, recompression, and recycle to storage for re-use.
Embodiments of valves for use in the invention will now be described by way of example only, with reference to the accompanying drawings, in which:
Figure 1 is a side elevation view, partly in section, of one exhaust valve;
Figure 2 is a section along the lines 2-2 of Figure l;
Figure 3 is a side elevation view, partly in section, of another exhaust valve;
Figure 4 is a side elevation view, partly in section of a third exhaust valve;
Figure 5 is a side elevation view, partly in section, of a fourth valve;
Figure 6 is a section along lines 6-6 of Figure 5;
Figure 7 is a plan view, with parts broken away, of a valve according to the inve~ltion;
Figure 8 is a vertical section through the valve of Figure 7; and 4~1 .
Fi~re 9 is an elevation view, in section, of a pressure release valve according to the invention for controlling gas $10w Erom an e~haust line connected to an exhaust valve according to the invention.
In the drawings, like features are lndicated by like reference numerals. t?
The valve illustrated in Figures 1 and 2 has a valve body 2;
~--an e~haust duct 4 extends axially through the valve body from one face
3 partially towards the other and then radially to its surface. The outlet 6 of the exhaust duct is adapted for connection ~e.g. by a screw thread as shown) to a hose (not shown) for exhaust gases. Three inlet du~ts 8 are disposed parallel to and symmetrically around the axial part of exhaust duct 4 and extend from the same face 3 of the valve body 2 to a common inlet 10 through the opposite face of the valve body.
lS The projecting portion 12 of the inlet lO is adapted for connectiondirectly to and through the wall of a diver's helmet (not shown). A
aiaphragm 14 incorporating a central valve plate or member 18 is secured æ ound its rim between the face 3 of valve body 2 and a protective cap 20; the cap 20 has apertures 22, so that the face 24 of the valve member 18 is exposed to the external amb-ient pressure, e.g. to the water pressure when in use. The valve plate 18 normally seats over and closes inlet ducts 8 and exhaust duct 4, cutting off communication therebetween.
When in use at a given depth, with the inlet co~municatlng with the interior of a diver's helmet and the exhaust duct outlet connected to an exhaust hose, the helmet pressure îs maintained at an appropriate breathing pressure and the exhaust duct at a reduced pressure such that the external water pressure will normally maintain t~e valve plate in this closed seated position, but that increase in 'he ~n et duct : ~
:: . . .. :
': :
pressure (e.g. due to exhalation by the diver) moves the valve plate to an open position as shown in Figure 1 against the external water pressure until gas has been exhausted via the exhaust duct. ~ovement of the valve plate 18 can be guided by three pins 25 which slide in bores 26 in -~he valve body 2, but these are not usually needed and are preferably omitted to leave no parts which move or slide in contact in operation of the valve.
The valve shown in Figure 3 is similar but has wider inlet ducts and a narrower exhaust duct to decrease the inlet duct pressure required, for a given external pressure, to open the valve.
The valve of Figure 4 is also similar, but the valve plate 18 in its closed position seats on valve seat 30 constituted by an extension of duct 4 integral with and projecting from face 3 of the valve body 2. This increases the area of the valve member exposed lS to the inlet duct pressure and reduces the value of this pressure required to open the valve.
In the valve of Figures 5 and 6 face 3 is re-entrant and ~e pins 25 carry a valve disc or plate 23 which normally seats over valve seat 30 in face 3 to close exhaust duct 4. The pins 25 are in fact not essential and are preferably omitted. Valve disc 23 may instead be mounted on legs extending only from ltself to the plate 18;
it may for example be formed from a disc with a plurality of radially projecting tabs which are bent at right angles to the disc to form legs which are affixed (e.g. by silver soldering) to -the plate 18.
Figures 7 and 8 show an improved exhaust valve in which a pair o diaphragms 14 with respective central valve plates 18, 18' for seating on respective valve seats 30, 30', control ~le ex~lal~stion of gas to a common exhaust duct 4. Exhaust gas enters tre valve body 2 by inlet ducts 8 and channels 9 and lifts each valve plate 18 from its seat 30 against the ambient water pressure acting on the external face 24 of the valve plate to which the water has access via apertures 22 in each protective cap 20; the gas is thus exhausted via the lower pressure exhaust duct 4 until the water pressure returns the valve plates to close the valve. Valve seat 30 is narrower, e.g. 2 mm internal diameter, than 30', e.g. 5 mm internal diameter, the two halves of the valve being otherwise substantially identical. This is advantageous, member 18 moving most readily from seat 30 on increase in inlet duct pressure and the resulting increase in outlet duct pressure due to the exhaust gas facilitating unseating of member 18'. The valve will be attached, e.g. to a diver's helmet, by screw-threaded boss 13.
The illustrated valves are simple but effective and reliable in operation, and can be machined for the most part from a single block of metal. A distinct advantage of the preferred valves is the absence of moving or mechanical parts which are liable to jam, wear or fail so as to endanger the user; the only moving or mechanical part needed is the diaphragm with its valve member.
Figure 9 illustrates a pressure release valve for an exhaust line, e.g. at the surface, for controlling the exhaust duct pressure and the release of exhaust gas, e.g. to the intake of a compressor. It has an inlet 40 connectable to an exhaust line for communication with the exhaust duct of the exhaust valve of a submersible enclosure according to the invention; outlet 42 may be connected to the intake, low pressure, side of a compressor B ~ which compresses the exhaust gas and passes it to high pressure gas reservoir for storage for re-use. A carbon dioxide scrubber .
' unit can be connected between the pressure release valve and the compressor or between the compressor and the reservoir.
Passage of exhaust gas from inlet 40 to outlet 42 is controlled by a valve plate 44 supported in a diaphragm 46 for movement into and out of ,~_~
- 8a -seating engagement with a valve seat 48. The face 50 of the valvq plate is exposed to the fluid pressure ma~ntaired in a closed cylinder 52; this predetermined pressure may be selected and adjusted at will.
This control valve is thus essentially the sa~e in structure and operation as the exhaust valves except for face 50 being subject to a predetermined, maintained pressure; when the exhaust line pressure exceeds this, on receipt of exhaust or exhaled gas, plate 44 is unseated ~to.allow the release of the exhaust gas. In a preferred operation the whole gas supply and exhaust system, including the exhaust line, is pressurised up to the appropriate working pressure, cylinder 5~ being brought to this pressure by opening by-pass 53; valve 54 is then shut to isolate cylinder 52 and needle valve 56 operated to reduce the pressure therein by a required amount, e.g. 1, 2 or 3 bar, as moni~ored on oauge 58; some gas accordingly exhausts from the exhaust line until the inlet 40 and selected cylinder 52 pressures substantially equalise, and the system is then set ready for use. This preferred control valve can be used with exhaust valves other than those according to the i~vention.
.
lS The projecting portion 12 of the inlet lO is adapted for connectiondirectly to and through the wall of a diver's helmet (not shown). A
aiaphragm 14 incorporating a central valve plate or member 18 is secured æ ound its rim between the face 3 of valve body 2 and a protective cap 20; the cap 20 has apertures 22, so that the face 24 of the valve member 18 is exposed to the external amb-ient pressure, e.g. to the water pressure when in use. The valve plate 18 normally seats over and closes inlet ducts 8 and exhaust duct 4, cutting off communication therebetween.
When in use at a given depth, with the inlet co~municatlng with the interior of a diver's helmet and the exhaust duct outlet connected to an exhaust hose, the helmet pressure îs maintained at an appropriate breathing pressure and the exhaust duct at a reduced pressure such that the external water pressure will normally maintain t~e valve plate in this closed seated position, but that increase in 'he ~n et duct : ~
:: . . .. :
': :
pressure (e.g. due to exhalation by the diver) moves the valve plate to an open position as shown in Figure 1 against the external water pressure until gas has been exhausted via the exhaust duct. ~ovement of the valve plate 18 can be guided by three pins 25 which slide in bores 26 in -~he valve body 2, but these are not usually needed and are preferably omitted to leave no parts which move or slide in contact in operation of the valve.
The valve shown in Figure 3 is similar but has wider inlet ducts and a narrower exhaust duct to decrease the inlet duct pressure required, for a given external pressure, to open the valve.
The valve of Figure 4 is also similar, but the valve plate 18 in its closed position seats on valve seat 30 constituted by an extension of duct 4 integral with and projecting from face 3 of the valve body 2. This increases the area of the valve member exposed lS to the inlet duct pressure and reduces the value of this pressure required to open the valve.
In the valve of Figures 5 and 6 face 3 is re-entrant and ~e pins 25 carry a valve disc or plate 23 which normally seats over valve seat 30 in face 3 to close exhaust duct 4. The pins 25 are in fact not essential and are preferably omitted. Valve disc 23 may instead be mounted on legs extending only from ltself to the plate 18;
it may for example be formed from a disc with a plurality of radially projecting tabs which are bent at right angles to the disc to form legs which are affixed (e.g. by silver soldering) to -the plate 18.
Figures 7 and 8 show an improved exhaust valve in which a pair o diaphragms 14 with respective central valve plates 18, 18' for seating on respective valve seats 30, 30', control ~le ex~lal~stion of gas to a common exhaust duct 4. Exhaust gas enters tre valve body 2 by inlet ducts 8 and channels 9 and lifts each valve plate 18 from its seat 30 against the ambient water pressure acting on the external face 24 of the valve plate to which the water has access via apertures 22 in each protective cap 20; the gas is thus exhausted via the lower pressure exhaust duct 4 until the water pressure returns the valve plates to close the valve. Valve seat 30 is narrower, e.g. 2 mm internal diameter, than 30', e.g. 5 mm internal diameter, the two halves of the valve being otherwise substantially identical. This is advantageous, member 18 moving most readily from seat 30 on increase in inlet duct pressure and the resulting increase in outlet duct pressure due to the exhaust gas facilitating unseating of member 18'. The valve will be attached, e.g. to a diver's helmet, by screw-threaded boss 13.
The illustrated valves are simple but effective and reliable in operation, and can be machined for the most part from a single block of metal. A distinct advantage of the preferred valves is the absence of moving or mechanical parts which are liable to jam, wear or fail so as to endanger the user; the only moving or mechanical part needed is the diaphragm with its valve member.
Figure 9 illustrates a pressure release valve for an exhaust line, e.g. at the surface, for controlling the exhaust duct pressure and the release of exhaust gas, e.g. to the intake of a compressor. It has an inlet 40 connectable to an exhaust line for communication with the exhaust duct of the exhaust valve of a submersible enclosure according to the invention; outlet 42 may be connected to the intake, low pressure, side of a compressor B ~ which compresses the exhaust gas and passes it to high pressure gas reservoir for storage for re-use. A carbon dioxide scrubber .
' unit can be connected between the pressure release valve and the compressor or between the compressor and the reservoir.
Passage of exhaust gas from inlet 40 to outlet 42 is controlled by a valve plate 44 supported in a diaphragm 46 for movement into and out of ,~_~
- 8a -seating engagement with a valve seat 48. The face 50 of the valvq plate is exposed to the fluid pressure ma~ntaired in a closed cylinder 52; this predetermined pressure may be selected and adjusted at will.
This control valve is thus essentially the sa~e in structure and operation as the exhaust valves except for face 50 being subject to a predetermined, maintained pressure; when the exhaust line pressure exceeds this, on receipt of exhaust or exhaled gas, plate 44 is unseated ~to.allow the release of the exhaust gas. In a preferred operation the whole gas supply and exhaust system, including the exhaust line, is pressurised up to the appropriate working pressure, cylinder 5~ being brought to this pressure by opening by-pass 53; valve 54 is then shut to isolate cylinder 52 and needle valve 56 operated to reduce the pressure therein by a required amount, e.g. 1, 2 or 3 bar, as moni~ored on oauge 58; some gas accordingly exhausts from the exhaust line until the inlet 40 and selected cylinder 52 pressures substantially equalise, and the system is then set ready for use. This preferred control valve can be used with exhaust valves other than those according to the i~vention.
.
Claims (8)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. An exhaust valve comprising a valve body, an inlet duct in the valve body for receiving gas to be exhausted through the valve, an exhaust duct in the valve body for exhausting the said gas from the valve, and two valve members, each valve member being subject on the one hand to the ambient external pressure and on the other hand to the pressures in the inlet and exhaust ducts, and both valve members moving according to changes in the said pressures between an open position in which there is communication between inlet and exhaust ducts for the exhaustion of gas through the valve and a closed position in which it cuts off such communication.
2. An exhaust valve according to claim 1 wherein each valve member is mounted in a diaphragm.
3. An exhaust valve according to claim 2 wherein one valve member opens more readily than the other under a given inlet duct pressure.
4. An exhaust valve according to claim 2 wherein said valve members seat on respective exhaust duct orifices one said orifice being of smaller cross-sectional area than the other.
5. A normally closed gas exhaust valve comprising a valve body partially defining a valve chamber, an inlet duct opening into the chamber for receiving gas to be exhausted through the valve, a pair of diaphragms forming respective opposed wall portions of the chamber, an exhaust duct which terminates in orifices opening into the chamber for the exhaustion of gas from the chamber, the orifices facing the respective diaphragms and being in close communication via the exhaust duct, and respective valve members carried by the diaphragms and urged into seating position on the respective orifices, the diaphragms each being exposed on one face solely to the ambient external pressure and on the other face to the combined pressures in the inlet and outlet ducts whereby each valve member moves accordingly to the pressure drop thereacross between a first normal seated position preventing communication between the inlet exhaust ducts and a second unseated position permitting such communication for the exhaustion of gas through the valve.
6. A valve according to claim 5 in which one valve member unseats more readily than the other.
7. A valve according to claim 6 in which unseating of the more readily unseatable valve member increases the exhaust duct pressure to facilitate unseating of the other valve member.
8. A valve according to claim 7 in which the more readily openable valve member seats on an orifice of smaller cross-sectional area than the orifice on which the other valve member seats.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB767176 | 1976-02-26 | ||
| GB7671/76 | 1976-02-26 | ||
| GB1978776 | 1976-05-13 | ||
| GB19787/76 | 1976-05-13 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1098411A true CA1098411A (en) | 1981-03-31 |
Family
ID=26241585
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA273,370A Expired CA1098411A (en) | 1976-02-26 | 1977-02-28 | Divers exhaust valve |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1098411A (en) |
-
1977
- 1977-02-28 CA CA273,370A patent/CA1098411A/en not_active Expired
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |