Claims
- 1. A method of manufacturing a gas impervious bursting membrane for use as a pressure release device comprising the steps of:providing a porous unimpregnated graphite membrane having a pressure surface and a surface opposite said pressure surface; coating at least one of said surfaces of said unimpregnated graphite membrane with a fluoropolymer in a flowable state; and sintering the fluoropolymer coating on said at least one of said surfaces of said graphite membrane.
- 2. A method as claimed in claim 1 further comprising the step of machining the membrane to the desired size or shape either before or after the coating and/or sintering step.
- 3. A method as claimed in claim 1 wherein said sintering step further comprises the step of raising the temperature of the graphite membrane and fluoropolymer coating in the range 300-600° C. for a predetermined period.
- 4. A method as claimed in claim 3 wherein the step of raising the temperature comprises the step of raising the temperature in the range of 350° C. to 550° C. for a predetermined period.
- 5. A pressure relief device comprising an unimpregnated graphite bursting membrane having side and edge surfaces, a pressure side, and a gas impermeable coating applied only to said pressure side, wherein the coating comprises a fluoropolymer and is a surface coating sintered to the membrane.
- 6. A pressure relief device as claimed in claim 5 wherein the coating comprises polytetrafluoroethylene.
- 7. A pressure relief device as claimed in claim 5 wherein the membrane comprises a porous graphite membrane.
- 8. A pressure relief device as claimed in claim 5 wherein the coating is of a thickness in the range of 5 microns to 300 microns.
- 9. A pressure relief device as claimed in claim 8 wherein the thickness is in the range of 25 to 125 microns.
- 10. A pressure relief device as claimed in claim 5 wherein the coating is holiday free.
- 11. A pressure relief device as claimed in claim 5 wherein the coating and graphite disc are sintered at temperatures in the range of 300-600° C.
- 12. A pressure relief device as claimed in claim 11 wherein the coating and graphite disc are sintered at temperatures in the range of 350-500° C.
- 13. A bursting disc incorporating such a pressure relief device as claimed in claim 5, said bursting disc being of the mono block type or of the replacement element type.
- 14. A bursting disc as claimed in claim 13 having a steady state operating temperature in excess of 200° C.
Priority Claims (2)
Number |
Date |
Country |
Kind |
9524415 |
Nov 1995 |
GB |
|
9619341 |
Sep 1996 |
GB |
|
CROSS-REFERENCES TO RELATED APPLICATIONS
The present application is a 371 of PCT/GT96/02949 filed Nov. 28, 1996.
PCT Information
Filing Document |
Filing Date |
Country |
Kind |
102e Date |
371c Date |
PCT/GB96/02949 |
|
WO |
00 |
7/29/1997 |
7/29/1997 |
Publishing Document |
Publishing Date |
Country |
Kind |
WO97/20159 |
6/5/1997 |
WO |
A |
US Referenced Citations (3)
Number |
Name |
Date |
Kind |
4102469 |
Shegrund et al. |
Jul 1978 |
|
4631200 |
Bierschenk |
Dec 1986 |
|
5012945 |
Kennan |
May 1991 |
|
Foreign Referenced Citations (4)
Number |
Date |
Country |
2 143 939 |
Mar 1973 |
DE |
1.466.386 |
Dec 1966 |
FR |
909379 |
Oct 1962 |
GB |
WO9321616 |
Oct 1993 |
WO |