GB2186036A - Seal-failure and seal-testing system - Google Patents
Seal-failure and seal-testing system Download PDFInfo
- Publication number
- GB2186036A GB2186036A GB08608910A GB8608910A GB2186036A GB 2186036 A GB2186036 A GB 2186036A GB 08608910 A GB08608910 A GB 08608910A GB 8608910 A GB8608910 A GB 8608910A GB 2186036 A GB2186036 A GB 2186036A
- Authority
- GB
- United Kingdom
- Prior art keywords
- mechanical seal
- pressure
- supply
- pressure fluid
- line
- 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.)
- Granted
Links
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
- F16J—PISTONS; CYLINDERS; SEALINGS
- F16J15/00—Sealings
- F16J15/16—Sealings between relatively-moving surfaces
- F16J15/34—Sealings between relatively-moving surfaces with slip-ring pressed against a more or less radial face on one member
- F16J15/3492—Sealings between relatively-moving surfaces with slip-ring pressed against a more or less radial face on one member with monitoring or measuring means associated with the seal
-
- 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
- F16J—PISTONS; CYLINDERS; SEALINGS
- F16J15/00—Sealings
- F16J15/002—Sealings comprising at least two sealings in succession
- F16J15/004—Sealings comprising at least two sealings in succession forming of recuperation chamber for the leaking fluid
-
- 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
- F16J—PISTONS; CYLINDERS; SEALINGS
- F16J15/00—Sealings
- F16J15/002—Sealings comprising at least two sealings in succession
- F16J15/008—Sealings comprising at least two sealings in succession with provision to put out of action at least one sealing; One sealing sealing only on standstill; Emergency or servicing sealings
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M3/00—Investigating fluid-tightness of structures
- G01M3/02—Investigating fluid-tightness of structures by using fluid or vacuum
- G01M3/26—Investigating fluid-tightness of structures by using fluid or vacuum by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors
- G01M3/28—Investigating fluid-tightness of structures by using fluid or vacuum by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors for pipes, cables or tubes; for pipe joints or seals; for valves ; for welds
- G01M3/2853—Investigating fluid-tightness of structures by using fluid or vacuum by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors for pipes, cables or tubes; for pipe joints or seals; for valves ; for welds for pipe joints or seals
- G01M3/2869—Investigating fluid-tightness of structures by using fluid or vacuum by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors for pipes, cables or tubes; for pipe joints or seals; for valves ; for welds for pipe joints or seals for seals not incorporated in a pipe joint
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Examining Or Testing Airtightness (AREA)
Abstract
A system for warning of failure of the primary mechanical seal of a mechanical seal arrangement including a primary mechanical seal 11 and a secondary mechanical seal 12 comprises a supply 14 of pressure fluid adapted to activate pressure actuable audible and/or visual alarm means 19,18, normally closed control valve means 20 normally isolating the supply 14 from the alarm means, and a product leakage line 28 connecting the seal arrangement and the valve means 20 whereby upon failure of seal 11 fluid product leaks to the valve means 20 to cause same to open and permit passage of the activating pressure fluid to the alarm means to operate same. The system can also comprise a rotary switch valve 23 to which is connected the pressure fluid supply 14, the product leakage line 28 and the exhaust outlet 27. To check seal 12 part of line 28 is primed with fluid pressure from the supply 14 and then isolated from the latter by the rotary switch valve 23 whereby deterioration of the secondary seal 12 is indicated by any pressure drop. <IMAGE>
Description
SPECIFICATION
Mechanical seals
This invention relates to mechanical seals.
It is well known to provide a mechanical seal arrangement consisting of a primary mechanical seal and a secondary mechanical seal, the latter coming into action on failure ofthe primary mechanical seal.
It is highly desirable that a warning be given upon primary mechanical seal failure, especially but not exclusively when the mechanical seal arrangement is being used to seal dangerous fluid products such as poisonous and/orflammablefluid products. The operator of the system incorporating the mechanical seal arrangement will then be aware that the sealing ofthe system is dependent upon the secondary mechanical seal and will then beina position to take immediate or timely action to replace the failed primary mechanical seal.
It will be manifest that if a mechanical seal arrangementas aforesaid has been operationai for some considerable time then there might be deterioration of the secondary seal and consequently there is a risk of total seal failure, i.e. failure of both the primary and secondary mechanical seals simultaneously or successively in a period of time inadequate to permit replacement of the failed primary mechanical seal.
It is therefore an object ofthe present invention to provide a system adapted to give warning offailure ofthe primary mechanical seal of a mechanical seal arrangement comprising a primary mechanical seal and a secondary mechanical seal.
It is another object of the present invention to provide a system for checking the status or condition of a secondary mechanical seal of a mechanical seal arrangement comprising a primary mechanical seal and a secondary mechanical seal.
As aforesaid such mechanical seal arrangements are often used to seal product lines through which dangerous fluid products are conveyed and it isyet another object ofthe present invention to provide a primary mechanical seal failure warning system and a secondary mechanical seal status or condition checking system which is purely pressure activated and which does not employ any electrical or battery power so that the warning and checking systems are intrinsically safe. This is particularly desirablewhen thefluid product is flammable.
Where the expression "mechanical seal arrangement" is used hereinafter it is to be understood that this means an arrangement including a primary mechanical seal and a secondary mechanical seal.
According to the present invention there is provided a system for warning offailure of the primary mechanical seal of a mechanical seal arrangement, the system comprising a supply of pressurefluid adapted to activate pressure actuable audible and/or visual alarm means, normally closed control valve
means normally isolating the supply of pressure fluid from the alarm means, a product leakage line connecting the mechanical seal arrangement and the normally closed control valve means whereby upon failure ofthe primary mechanical seal fluid product leaks to the normally closed control valve means to cause same to open and permit passage of the ac tivating pressure fluid to the alarm means to operate same.
Preferably the normal closed control valve means is pilot operated.
Preferably the warning system includes a pressure activated visual indicator upstream ofthe normally closed control valve means in terms of activating pressure fluid flow to indicate that the warning system is primed with activating fluid up to the nor mallyclosed control valve.
Preferably the alarm means comprises a visual indicator and an audible alarm, the former being downstream of the normally closed control valve means in terms of activating pressure fluid flow and the audible alarm being downstream of the warning visual indicator in terms of such fluid flow.
Preferably the system includes between the visual warning indicator and the audible alarm a normally open control valve operable to close off the audible alarm once the failure of the primary mechanical seal has been noted. The normally open control valve may be key operated to closed and opened positions.
Preferably the pressure fluid supply is either an air supply, for example tapped from a general factory air supply, or is CO2 supplied from, for example, a selfcontained CO2 reservoir.
The warning system preferably comprises, downstream of the pressure fluid supply and upstream of the warning visual indicatorand normallyclosed control valve, a stop valve and a pressure regulator with pressure gauge.
The system primed visual indicator is preferably coloured green while the warning visual indicator is preferably coloured red. These indicators are prefer- ably what are known as "pressure lights", i.e. a col oured element is caused to move in front of a window underthe action of pressure fluid.
A pressure gauge is preferably connected to the product leakage line so that the pressure of the leaking product can be seen.
The warning system preferably comprises a rotary switch valve connected to a product exhaust outlet (at which the product may be flamed if necessary), which rotary switch valve is also connected to an alarm activating pressure fluid supply line and to the product leakage line, the rotary switch valve isolating these lines one from another and being operable to connect the product leakage line to the product exhaust outlet.
Preferably, the rotary switch valve is keyed (i.e. key operable) to restrict unauthorised use.
Preferably the alarm activating pressure fluid supply line connected to the rotary switch valve incorporates a non-return valve upstream of the rotary switch valve in said line which is primed with activating pressure fluid up to the rotary switch valve in the normal standby mode condition ofthewarning system.
According to a second aspect of the present invention there is provided a system for checking the status or condition of a secondary mechanical seal of
a mechanical seal arrangement, the system compris
ing a supply of pressure fluid connectible via a pressure line to the mechanical seal arrangement, a nor mally closed valve in the pressure line adapted to isolate the pressure fluid from the mechanical seal arrangement and openable to permit flow of pressurefluid tothe mechanical seal arrangementfor status or condition check purposes, the pressure line also incorporating a pressure gauge.
Preferably the normally closed valve means is operableto isolate part ofthe pressure line primed with pressure fluid from the supply of pressure fluid whereby any pressure drop due to decay ofthe secondary mechanical seal can be detected by an inspection ofthe pressure gauge.
Preferably the normally closed valve means is operableto connectthe primed part ofthe pressure line connected to the mechanical seal arrangementto an exhaust outlet.
Preferably the normally closed valve means is a rotary switch valve to which is connected the activating alarm pressure fluid supply, the product leakage line and the exhaust outlet, the product leakage line being used when checking the status or condition of the secondary mechanical seal, i.e. it is the partofthe aforesaid pressure line which is primed with fluid pressure from the activating alarm pressure fluid supply and which is isolated from the latter bythe rotary switch valve to permitthe status of condition of the secondary mechanical seal to be determined by any pressure drop thus indicating whether or not there is decay ofthe secondary mechanical seal.
Thus when checking the status or condition of the secondary mechanical seal there is simultaneous testing ofthe alarm means since the alarm activating pressure fluid operates the pilot operated normally closed control valve to open same to the activating fluid pressure supply. The alarm means can be these ted with orwithoutthe audible alarm operational.
An embodiment of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which Figure lisafluid pressure circuit diagram of a combined primary mechanical seal failure warning system and secondary mechanical seal status checking system,the circuit being in the normal standby mode condition;
Figure 2 is a view ofthe circuit indicating the condition of the circuitwhen there is a pressure leakfrom the primary mechanical seal;
Figure 3 is a view ofthe circuit indicating the condition of the circuit with the leaking product being exhausted to atmosphere with flaming ofthe product if necessary;
Figure 4 is a view ofthe circuit showing the condition ofthe circuit when the status or condition ofthe secondary mechanical seal is being checked;;
Figure 5is a view of the circuit showing the condition ofthe circuit when testing the status, i.e. degree of deterioration, if any, of the secondary mechanical seal; and
Figure 6 is a view of the circuit showing the condition ofthe circuit when the fluid pressure is being exhausted aftertesting of the secondary mechanical seal.
The mechanical seal arrangement is indicated at 10 and comprises a primary mechanical seal 11 and a secondary mechanical seal 12. In this case the secondary mechanical seal 12 is a dry running contact seal but the present invention is not restricted to such secondary mechanical seals.
The circuit is provided with a supply of activating pressure fluid which is preferably either a factory air supply 13 or CO2 normally provided from a reservoir 14. Both of these supplies may be provided with the
CO2 supply serving as a backup should the main air supply fail for whatever reason. The supply of activating pressure fluid 13 or 14 is delivered into the warning and checking system via a stop valve 15 and a pressure regulator 16 with associated pressure gauge 17.
The elements of the system which warn of a leakage from the primary mechanical seal 11 comprise a visual indicator 18 in the form of a pressure lamp as previously mentioned and an audible alarm 19 (whistle or siren). A normally closed pilot operated control valve 20 is disposed upstream ofthewarning elements 18 and 19 and in the standby condition of
Figure 1 serves to isolate these warning elements 18 and 19 from the activating pressure fluid supply.
Between the pressure lamp 18 and the audible alarm 19 is a key operated normally open control valve 21. This valve can be used to isolate the audible alarm 19 from the warning system orto shut off the audible alarm once the warning system has been activated and the failure of the primary secondary seal 11 noted by operatives.
The combined warning and checking system incorporates downstream of the control valve 20 a second visual indicator 22 again in the form of a pressure lamp. The purpose of this indicator 22 is to show that the system is primed with activating pressure fluid.
The warning visual indicator 18 is preferably coloured red while the primed visual indicator 22 is preferably coloured green. Other colours may be employed provided the two indicators are of different colours.
The system further includes a four-position rotary switch valve 23 which is normally closed.
The rotary switch valve is connected to the activating pressurefluid supply 13 or 14 via a pressure line 24 incorporating a pressure regulator 25 and anon- return valve 26.
The rotary switch valve 23 is also connected to an exhaust outlet 27 through which eitheractivating pressure fluid or product can be exhausted.
Finally, the rotary switch valve is connected tothe mechanical seal arrangement by a product line 28 which incorporates a pressure gauge 29 and from which there is a branch line 30 to the pilot of the pilot operated control valve 20.
In Figure lit can be seen that the cicuit of the com- bined warning and checking system is primed with activating air or CO2. In this normal standby mode conditionthevisual indicator22 has been operated to indicate the priming condition and the circuit is filled with air or CO2 as far as the control valve 20 and the rotary switch valve 23 which isolates the air or CO2supplyfrom the product line 28 and the exhaust outlet 27, the control valve 20 isolating the warning visual indicator 18 and the audible alarm 19 from the air or CO2 supply.
The condition of the circuit which occurs when there is failure ofthe primary mechanical seal 11 ora leakagetherefrom is shown in Figure 2 and here it will be seen that product flowing along pressure line 28 operates the pressure gauge 29 and also via the branch line 30 operates the pilot operated control valve20to open same and allow activating airorCO2 to operate the warning visual indicator 18 and via the control valve 21 the audible alarm 19.
When the failure or leakage from the primary mechanical seal 11 has been noted the audible alarm 19 can be shut off by means of the key operated control valve 21.
The mechanical seal arrangement is now running on the secondary mechanical seal 12 and operatives can thus take action to repiace the failed or damaged primary mechanical seal 11.
Figure 3 shows the condition of the circuit in which action has been taken to exhaust product from the product line 28 through the exhaust outlet 27. This is effected by operating the rotary switch valve 23 to connect the pressure line 28 to the exhaust outlet 27.
Itwill be noted that in this condition the audible alarm 19 is normally rendered inoperative by the control valve 21.
When it is desired to check the status or condition ofthe secondary mechanical seal 12, which can be done at regular intervals or whenever is appropriate, the rotary switch valve 23 is operated to connectthe activating airorCO2 supply 13 or 14to the product pressure line 28 thereby pressurising the secondary mechanical seal 12. This also servesto operatethe warning visual indicator 18 and, if in circuit, the aud- ible alarm 19 due to activating air or CO2 passing along branch line 30 to open the pilot operated control valve 20.
By operating the rotary switch valve to isolate the pressurised product line 28 from the activating air or CO2 supply 13 or 14the status or condition of the secondary mechanical seal 12 can be determined by any pressure drop which will be shown on the pressure gauge 29 (see Figure 5).
To clearthe product line 28 of pressurised airor CO2 the rota ry switch valve 23 is operated to connect the pressure line 28 to the exhaust outlet 27 and this permits the pilot operated control valve to close (see
Figure 6).
The combined warning and testing system ofthe present invention can be applied to multiple mechanical seal arrangements and a selected mechanical seal arrangement can be tested at will. It will be man ifest that appropriate valving will be provided in such a multiple mechanical seal situation.
It is to be noted that the rotary switch valve 23 is keyed to restrict unauthorised use.
Claims (22)
1. Asystemforwarning offailureoftheprimary mechanical seal of a mechanical seal arrangement, the system comprising a supply of pressure fluid adapted to activate pressure actuable audible and/or visual alarm means, normally closed control valve
means normally isolating the supply of pressure fluid from the alarm means, a product leakage line connecting the mechanical seal arrangement and the normally closed control valve means whereby upon failure ofthe primary mechanical seal fluid product leaks to the normally closed control valve means to cause same to open and permit passage of the activating pressure fluid to the alarm means to operate same.
2. A system as claimed in claim 1, in which the normally closed control valve means is pilot operated.
3. Asystem as claimed in claim 1 or2,compris- ing a pressure activated visual indicator upstream of the normally closed control valve means in terms of activating pressure fluid flow to indicate that the warning system is primed with activating fluid upto the normally closed control valve.
4. Asystem as claimed in any one of claims 1 to 3 in which the alarm means comprises a visual indicator and an audible alarm, the former being downstream of the normally closed control valve means in terms of activating pressure fluid flow and the audible aiarm being downstream of the warning visual indicator in terms of such fluid flow.
5. A system as claimed in claim 4, including be tweenthevisualwarning indicator and the audible alarm a normally open control valve operable to close offthe audible alarm oncethefailure ofthe primary mechanical seal has been noted.
6. Asystem as claimed in claim 5, in which the normally open control valve is key operated to closed and opened positions.
7. Asystem as claimed in any one of claims 1 to 6, in which the pressurefluid supply is eitheran air supply, for example tapped from a general factory air supply, or is CO2 supplied from, for example, a self- contained CO2 reservoir.
8. Asystem as claimed in any one of claims 1 to 7 comprising, downstream ofthe pressure fluid supply and upstream of the warning visual indicator and normally closed control valve, a stop valve and a pressure regulatorwith pressure gauge.
9. Asystem as claimed in any one of claims 3 to 8, in which the system primed visual indicator is prefer ably coloured green whilethe warning visual indicator is preferably coloured red.
10. Asystem asclaimed inclaimg,inwhichthe indicators are "pressure lights", i.e. a coloured element adapted to move in front of a window under the action of pressurefluid.
11. A system as claimed in any one of claims 1 to
10 comprising a pressure gauge connected to the product leakage line so that the pressure of the leaking product can be seen.
12. Asystem as claimed in any one of claims 1 to 11 comprising a rotary switch valve connected to a product exhaust outlet, which rotary switch valve is also connected to an alarm activating pressure fluid supply line and to the product leakage line, the rotary switch valve isolating these iines one from another and being operable to connectthe product leakage line to the product exhaust outlet.
13. A system as claimed in claim 12, in which the rotary switch valve is keyed to restrict unauthorised use.
14. Asystem as claimed in claim 12 or 13, in which the alarm activating pressure fluid supply line connected to the rotary switch valve incorporates a non-return valve and a pressure regulator upstream ofthe rotary switch valve in said line which is primed with activating pressure fluid up to the rotary switch valve in the normal standby mode condition of the warning system.
15. A system for checking the status or condition of a secondary mechanical seal of a mechanical seal arrangement, the system comprising a supply of pressure fluid connectible via a pressure line to the mechanical seal arrangement, a normally closed valve in the pressure line adapted to isolate the pressurefluid from the mechanical seal arrangement and openableto permit flow of pressure fluid to the mechanical seal arrangementforstatus or condition check purposes, the pressure line also incorporating a pressure gauge.
16. Asystem as claimed in claim 15, in which the normally closed valve means is operable to isolate partofthe pressure line primed with pressure fluid from the supply of pressure fluid whereby any pressure drop due to decay ofthe secondary mechanical seal can be detected by an inspection of the pressure gauge.
17. Asystem as claimed in claim 15 or 16, in which the normally closed valve means is operable to connect the primed part of the pressure line connected to the mechanical seal arranementto an exhaust outlet.
18. Asystem as claimed in anyone of claims 15 to 17 in which the normally closed valve means is a rotary switch valve to which is connected the activating alarm pressure fluid supply, the product leakage line and the exhaust outlet, the product leakage line being used when checking the status or condition of the secondary mechanical seal, i.e. it is the part of the aforesaid pressure line which is primed with fluid pressure from the activating alarm pressure fluid supply and which is isolated from the latter bythe rotary switch valve to permit the status or condition ofthe secondary mechanical seal to be determined by any pressure drop thus indicating whether or not there is deterioration of the secondary mechanical seal.
19. Asystem forwarning of failure of the primary mechanical seal of a mechanical seal arrangement, substantially as hereinbefore described with reference to the accompanying drawings.
20. A system for checking the status or condition of a secondary mechanical seal of a mechanical seal arrangement substantially as herein before described with reference to the accompanying drawings.
21. The combination ofwarning and checking systems as claimed in claim 1 and claim 15.
22. Thecombination of warning and checking systems according to any one of claims 1 to 14 and l9andanyoneofclaims 15to18and20
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB8814409A GB2204366B (en) | 1986-01-31 | 1986-04-11 | Mechanical seals |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB868602475A GB8602475D0 (en) | 1986-01-31 | 1986-01-31 | Mechanical seals |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| GB8608910D0 GB8608910D0 (en) | 1986-05-14 |
| GB2186036A true GB2186036A (en) | 1987-08-05 |
| GB2186036B GB2186036B (en) | 1989-11-01 |
Family
ID=10592347
Family Applications (2)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB868602475A Pending GB8602475D0 (en) | 1986-01-31 | 1986-01-31 | Mechanical seals |
| GB8608910A Expired GB2186036B (en) | 1986-01-31 | 1986-04-11 | Mechanical seals |
Family Applications Before (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB868602475A Pending GB8602475D0 (en) | 1986-01-31 | 1986-01-31 | Mechanical seals |
Country Status (1)
| Country | Link |
|---|---|
| GB (2) | GB8602475D0 (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2617261A1 (en) * | 1987-06-23 | 1988-12-30 | Eg & G Ltd | SEAL AND SECONDARY SEAL SYSTEM FOR DEVICE PLACED IN A HAZARDOUS ENVIRONMENT |
| GB2207201A (en) * | 1987-07-22 | 1989-01-25 | Hans Hucke | Device for preventing leakages at a component having a sealed fluid chamber |
| GB2259370A (en) * | 1991-09-09 | 1993-03-10 | Intevep Sa | Sensing oil leaks in stuffing box of walking beam pump system |
| WO1993019301A1 (en) * | 1992-03-20 | 1993-09-30 | Mannesmann Rexroth Gmbh | Hydraulic driving device with a cylinder |
| GB2271413A (en) * | 1992-10-09 | 1994-04-13 | Nuovo Pignone Spa | Improved seal system, particularly suitable for process valves |
| EP1207310A1 (en) * | 1999-07-23 | 2002-05-22 | Hitachi, Ltd. | Turbo fluid machinery and dry gas seal used for the machinery |
| CN102991531A (en) * | 2012-11-15 | 2013-03-27 | 连云港天明装备有限公司 | Operation alarming device of bracket transport cart |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB851118A (en) * | 1956-04-10 | 1960-10-12 | British Thomson Houston Co Ltd | Improvements in and relating to fluid seals |
| GB952755A (en) * | 1959-10-28 | 1964-03-18 | Gray Tool Co | Improved coupling for fluid pressure duct |
| GB989794A (en) * | 1961-03-27 | 1965-04-22 | Central Res Lab Inc | Rotary mechanical seal |
| US3546923A (en) * | 1969-02-05 | 1970-12-15 | Us Navy | Seal test stand and fixture |
| GB2143596A (en) * | 1983-07-19 | 1985-02-13 | Telspec Ltd | Improvements in and relating to the sealing of electrical cable joints equipment housings or the like |
-
1986
- 1986-01-31 GB GB868602475A patent/GB8602475D0/en active Pending
- 1986-04-11 GB GB8608910A patent/GB2186036B/en not_active Expired
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB851118A (en) * | 1956-04-10 | 1960-10-12 | British Thomson Houston Co Ltd | Improvements in and relating to fluid seals |
| GB952755A (en) * | 1959-10-28 | 1964-03-18 | Gray Tool Co | Improved coupling for fluid pressure duct |
| GB989794A (en) * | 1961-03-27 | 1965-04-22 | Central Res Lab Inc | Rotary mechanical seal |
| US3546923A (en) * | 1969-02-05 | 1970-12-15 | Us Navy | Seal test stand and fixture |
| GB2143596A (en) * | 1983-07-19 | 1985-02-13 | Telspec Ltd | Improvements in and relating to the sealing of electrical cable joints equipment housings or the like |
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2617261A1 (en) * | 1987-06-23 | 1988-12-30 | Eg & G Ltd | SEAL AND SECONDARY SEAL SYSTEM FOR DEVICE PLACED IN A HAZARDOUS ENVIRONMENT |
| GB2207201A (en) * | 1987-07-22 | 1989-01-25 | Hans Hucke | Device for preventing leakages at a component having a sealed fluid chamber |
| GB2259370A (en) * | 1991-09-09 | 1993-03-10 | Intevep Sa | Sensing oil leaks in stuffing box of walking beam pump system |
| GB2259370B (en) * | 1991-09-09 | 1995-04-12 | Intevep Sa | Apparatus for detection of oil leaks in stuffing box of walking beam pump system |
| WO1993019301A1 (en) * | 1992-03-20 | 1993-09-30 | Mannesmann Rexroth Gmbh | Hydraulic driving device with a cylinder |
| US5469704A (en) * | 1992-03-20 | 1995-11-28 | Mannesmann Rexroth Gmbh | Hydraulic drive apparatus comprising a cylinder |
| GB2271413A (en) * | 1992-10-09 | 1994-04-13 | Nuovo Pignone Spa | Improved seal system, particularly suitable for process valves |
| US5365971A (en) * | 1992-10-09 | 1994-11-22 | Nuovopignone-Industrie Meccaniche E Fonderia S.P.A. | Seal system, particularly suitable for process valves |
| GB2271413B (en) * | 1992-10-09 | 1996-08-14 | Nuovo Pignone Spa | Improved seal system, particularly suitable as part of a process valve |
| EP1207310A1 (en) * | 1999-07-23 | 2002-05-22 | Hitachi, Ltd. | Turbo fluid machinery and dry gas seal used for the machinery |
| EP1207310A4 (en) * | 1999-07-23 | 2005-12-07 | Hitachi Ltd | Turbo fluid machinery and dry gas seal used for the machinery |
| CN102991531A (en) * | 2012-11-15 | 2013-03-27 | 连云港天明装备有限公司 | Operation alarming device of bracket transport cart |
Also Published As
| Publication number | Publication date |
|---|---|
| GB2186036B (en) | 1989-11-01 |
| GB8608910D0 (en) | 1986-05-14 |
| GB8602475D0 (en) | 1986-03-05 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PCNP | Patent ceased through non-payment of renewal fee |
Effective date: 20030411 |