CA1172543A - Heat sensitive valve - Google Patents
Heat sensitive valveInfo
- Publication number
- CA1172543A CA1172543A CA000381272A CA381272A CA1172543A CA 1172543 A CA1172543 A CA 1172543A CA 000381272 A CA000381272 A CA 000381272A CA 381272 A CA381272 A CA 381272A CA 1172543 A CA1172543 A CA 1172543A
- Authority
- CA
- Canada
- Prior art keywords
- valve
- stem
- gate
- bonnet
- flowway
- 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
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
- F16K—VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING
- F16K17/00—Safety valves; Equalising valves, e.g. pressure relief valves
- F16K17/36—Safety valves; Equalising valves, e.g. pressure relief valves actuated in consequence of extraneous circumstances, e.g. shock, change of position
- F16K17/38—Safety valves; Equalising valves, e.g. pressure relief valves actuated in consequence of extraneous circumstances, e.g. shock, change of position of excessive temperature
- F16K17/383—Safety valves; Equalising valves, e.g. pressure relief valves actuated in consequence of extraneous circumstances, e.g. shock, change of position of excessive temperature the valve comprising fusible, softening or meltable elements, e.g. used as link, blocking element, seal, closure plug
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Safety Valves (AREA)
Abstract
ABSTRACT
A heat sensitive valve is provided which is operable to be moved between open and closed position during normal operations and upon being exposed to excessive temperatures, will auto-matically move to the closed position or to the open position depending upon the design of the valve element and which will move to such position under the influence of line pressure without producing any pieces or mechanisms which could act as projectiles and present a hazard to nearby personnel and equipment.
A heat sensitive valve is provided which is operable to be moved between open and closed position during normal operations and upon being exposed to excessive temperatures, will auto-matically move to the closed position or to the open position depending upon the design of the valve element and which will move to such position under the influence of line pressure without producing any pieces or mechanisms which could act as projectiles and present a hazard to nearby personnel and equipment.
Description
~7~543 HEAT SENSITIVE VALVE
This invention relates to a valve which in normal operation can be moved between open and closed posi-tions but which, when exposed to an selected high temperature level, will automatically be moved to a selected one of open or closed positions.
In many instances, it would be desirable to uti-lize a valve which, under normal circumstances, could be readily opened and closed to perform its normal valving function, but upon exposure of such valve to excessively high temperatures, such as in a fire, the valve would actuate to a selected one of open or closed positions. For example, such a valve could be used in refineries, chemical plants and the like as well as in christmas trees and flow lines in pro-ducing oil and gas wells to be automatically closed in the event of fire as a safety precaution and to prevent the fluid normally flowing through such valves from further feeding the fire. Such heat sen-sitive valves would thus "fail" to closed position.
On the other hand, there may be instances where it would be desired for the valve to "fail" to open position in the event of fire. For example, it might be desirable to vent fluid to a flare in the event of a fire. As indicated, with either type of valve, it would be desirable to be able to utilize the valve as a normal valve during day to day operations in the sense that the valve could be readily opened and closed at will.
~ ' ~72543 Many valves have been proposed which contain a fusible element which will cause some sort of res-ponse when exposed to a temperature sufficient to cause the element to fuse or melt. In one such type of valve, the fusible element continuously maintains the valve in either open or closed position until exposed to the elevated temperature at which time the valve will move to its other position. This type of valve can not be normally operated between open and closed positions but remains in one position until exposed to the elevated temperature. Another such type of valve employs a fusible element in such a manner that the valve can normally be moved between open and closed positions but, when the fusible ele-ment melts, the valve can fail only to open posi-tion. This type of valve is illustrated in U.S.
Patent No. 3,618,627 to Wagner. In addition, the fusible element as shown in the Wanger patent is lo-cated in the interior of the valve and the latter must be dismantled in order to replace the fusible element.
A very significant problem encountered in design-ing valves having the desired characteristics men-tioned above is to provide a fail safe operation which does not involve a portion of the valve becoming a "projectile" when the fusible element melts. Illustrative of this problem is the valve shown in U.S. Patent No. 3,842,854 to Wicke. In the Wicke patent, a valve operator is shown which becomes disengaged from the valve upon melting of a fusible ~72543 member. When such a valve is used in reasonably high pressure operations, e.g. 5000 psi, line pressure acting across the main valve stem will cause it to move abruptly to closed valve position when the operator becomes disconnected. This movement is so abrupt and so forceful that it causes the operator to become a projectile in effect, so that it will travel several tens of feet before it comes to rest. Ob-viously, this can be extremely hazardous.
To further il]ustrate the forces involved when high line pressures act to move a gate valve to closed posltion without any restraint on such move-ment, it has been observed that these forces can actually cause the valve bonnet to be torn from the main valve body when the gate slams against the bonnet.
It is an object of this invention to provide a heat sensitive valve operable to be moved between open and closed positions during normal operations and, upon being exposed to excessive temperatures, being operable to automatically move to the closed position or, depending upon the design of the valve element, to the open position.
Another object is to provide such a valve which, upon being exposed to excessive temperature, moves to one position under the influence of line pressure without producing any pieces or mechanisms which could act as projectiles and present a hazard to nearby personnel and equipment.
1~7~543 Another object i5 to provide such a valve wherein the fusible element is arranged in such a manner as to dampen the movement of the valve element and prevent it from slamming against the valve body or bonnet with excessive force.
Another object is to provide such a valve wherein the fusible element is exterior of the valving mechanism per se so that the element can be readily replaced and so that the valving mechanism can act in its normal manner upon melting of the fusible element.
Another object is to provide such a valve which is constructed so that after melting of the fusible element and movement of the valve to its fail safe position, it will be readily apparent to an observer that the valve is in such posltlon .
Other objects, advantages and features of the invention will be apparent to one skilled in the art upon a consideration of the written specification, the claims and the attached drawings.
In one aspect of the present invention there is provided a gate valve comprising a valve body having a gate valve comprising a valve body having inlet and outlet ends with means at each of said ends for connecting the valve to flow conduits, a flowway between such ends; a chamber intersecting the flowway and opening to one side of the valve body; a bonnet sealably connected to the valve body and having a bore there-through aligned with the chamber opening; a pair of annular spaced apart seats opposing each other and each having an opening therethrough coaxial with said flowway; a gate having parallel outwardly facing seating surfaces disposed between said seats at all times and reciprocal therebetween, said gate having an imperforate portion positionable between the seats and across the flowway to prevent flow therethrough when the ~17Z543 gate is moved to valve closed position and also having a port therethrough to be brought into alignment with the seats and the flowway to permit flow therethrough when the gate is in valve open position; actuating means for moving the gate between said valve closed and open positions including a valve stem attached to the gate and extending through the bore of the bonnet to the exterior of the bonnet; seal means between the stem and bonnet permitting movement of the stem while pre-venting escape of fluids from the bonnet; means for moving the stem outwardly consisting of the stem having an inner end exposed to line pressure within the valve body and an outer end exposed to atmospheric pressure exteriorly of the valve body such that a differential pressure effectively acts on the cross-sectional area of the stem within the seal means to provide the sole force to urge the stem outwardly of the valve body; said actuating means including a heat fusible element located outwardly of said seal means and disposed between opposing shoulders on the bonnet and the stem to transmit force developed by said actuating means to reciprocate the gate between valve closed and valve open positions but upon melting, being displaced by the stem being moved outwardly by said differential pressure so that said differential pressure will act on the stem to move it outwardly a distance that said gate will be moved fully from one of its valve closed and open positions to the other of such positions, said fusible element having a length at least equal to the distance said stem must move outwardly said distance.
In a further aspect of the present invention there is provided a heat sensitive valve comprising a valve body having a flowway therethrough and means at each end of the flowway for connecting the valve to flow conduits; a bonnet connected to the valve body and having a bore therethrough -4a-,,~, , ....
~ ~7Z543 communicating with said flowway, a pair of spaced apart seats in said body surrounding the flowway, a gate having outwardly facing parallel seating surfaces on either side thereof for simultaneous sliding contact with said seats respectively, said gate also having an imperforate portion positionable between the seats across the flowway to prevent flow therethrough when the gate is moved to valve closed position and also having a port therethrough to be brought into axial alignment with the seats and with the flowway to permit flow therethrough when the gate is in valve open position, a valve stem attached to the gate and extending through the bore oft~ bonnet to the exterior of the bonnet, said stem including a first internally thread hollow portion and a second externally threaded portion mating with said first portion so that upon relative rotation of the first and second stem portions, the second portion is caused to reciprocate the gate between valve open and valve closed positions; seal means between the stem and bonnet permitting movement of the stem while preventing escape of fluids from the bonnet, means for moving the stem outwardly consisting of the stem having an inner and exposed to line pressure wit~in the valve body and an outer end exposed to atmospheric pressure exteriorly of the valve body such that a differential pressure effectively acts on the cross-sectional area of the stem within the seal means to provide the sole force to urge stem outwardly of the valve body, a heat fusible e~ement connected between the bonnet and said first stem portion to normally transmit force developed during reciprocation of the gate between valve open and valve closed positions but upon melting, being displaced by the stem as the latter is moved outwardly by said differential pressure so that when said gate is in its one position as hereinafter defined said pressure differential will act on - 4b -~L~72543 the stem to move it outwardly a sufficient distance that said gate will be moved fully from one of its valve closed and valve open positions to the other end of such positions, said bonnet having a space therein around said first stem portion of sufficient magnitude such that, when said fusible element is melted, both the first and second stem portions are free to move outwardly said sufficient distance.
In a further a~spect of the present invention there is provided a gate valve comprising a valve body having inlet and outlet ends with means at each of said ends for connecting the valve to flow conduits; a flowway between such ends; a chamber intersecting the flowway and opening to one side of the valve body; a bonnet sealably connected to the valve body and having a bore therethrough aligned with the chamber open-ing; a pair of annular spaced apart seats opposing each other and each having an opening therethrough coaxial with said flowway; a gate having parallel outwardly facing seating surfaces disposed between said seats at all times and reciprocal therebetween, said gate having an imperforate portion positionable between the seats and across the flowway to prevent flow therethrough when the gate is moved to valve closed position and also having a port therethrough to be brought into alignment with the seats and the flowway to permit flow therethrough when the gate is in valve open position; actuating means for moving the gate between said valve closing and open positions including a valve stem attached to the gate and extending through the bore of the bonnet to the exterior of the bonnet; seal means between the stem and bonnet permitting movement of the stem while preventing escape of fluids from the bonnet; means for urging the stem outwardly of the valve body consisting of the stem having an inner end exposed to line pressure within the valve -4c-:.
~17Z543 body and an outer end exposed to atmospheric pressure exteriorly of the valve body such that a differential pressure effectively acts on the cross-sectional area of the stem within the seal means to provide the necessar~ force for urging the stem outwardly of the valve body said actuating means includ-ing a first shoulder on the bonnet, a second shoulder opposing the first shoulder and connected to the stem so that said differential pressure urging the stem outwardly of the body also urges the second shoulder towards the first shoulder, a heat fusible element disposed between said first and second shoulder and normally preventing the second shoulder from moving toward the first shoulder during normal opening and closing of the valve but upon melting being displaced from between said first and second shoulders to allow the stem to be moved outwardly a predetermined distance to move the second shoulder toward the first shoulder and in so doing to move the gate fully from one of its valve open or closed positions to the other of said positions, said fusible element having a length at least equal to said predetermined distance-In a further aspect of the present invention there is provided a heat sensitive valve comprising a valve body having a flowway therethrough and means at each end of the flowway for connecting the valve to flow conduits; a bonnet connected to the valve body and having a bore therethrough communicating with said flowway, a pair of spaced apart seats in said body surrounding the flowway; a gate having outwardly facing parallel seating surfaces on either side thereof for simultaneous sliding contact with said seats respectively, said gate ~lso having an imperforate portion positionable between the seats across the flow-away to prevent flow therethrough when the gate is moved to valve - 4d-~ ., , ~ , : L172S4~
closed position and also having a port therethrough to be brought into axial alignment with the seats and with the flowway to permit flow therethrough when the gate is in valve open position; a valve stem attached to the gate and extending through the bore of the bonnet to the exterior of the bonnet, said stem including a first internally threaded hollow portion having an outturned flange and a second externally threaded portion mating with said first portion so that upon relative rotation of the first and second stem portions, the second portion is caused to reciprocate the gate between valve open and valve closed positions; seal means between the st m and bonnet permitting movement of the stem while preventing escape of fluids From the bonnet; means for moving the stem outwardly consisting of the stem having an inner end exposed to line pressure within the valve body and an outer end exposed to atmospheric pressure exteriorly of the valve body such that a differential pressure effectively acts on the cross-sectional area of the stem within the seal means to provide the sole foroe to urge stem outwardly of the valve body; said bonnet having an inturned flange opposing said outturned flange and spaced therefrom a distance at least as great as that which the gate moves between is fully open and fully closed positions; a heat fusible element extending between said flanges to normally transmit foroe s developed during reciprocation of the gate between valve open and valve closed positions but upon melting, being displaced by the stem as the latter is moved outwardly by said differential pressure so that when said gate is in its one position as hereinafter defined, said pressure differential will act on the stem to move it outwardly a sufficient distance that said gate will be moved fully from one of its valve closed and valve open positions to the other of such positi~ns.
- 4e -1~72543 In a further aspect of the present invention there is provided a gate valve comprising a valve body having inlet and outlet ends with means at each of said ends for connecting the valve to flow conduits; a flowway between such ends; a chamber intersect1ng the flowway and opening to one side of the valve body; a bonnet sealably connected to the valve body and having a bore aligned with the chamber opening; a seat surrounding the flowway; a gate seatable on said seat to prevent flow through said flowway when the gate is moved to valve closed position and being movable from said seat to permit flow through said flowway when the gate is in valve open position, seal means between the stem and bonnet permitting movement of the stem while preventing escape of fluids from the bonnet; actuating means for moving the gate between said valve closed and open positions including a valve stem attached to the gate and extending through the bore of the bonnet to the exterio~ of the bonnet and having an outturned shoulder thereon; said bonnet having an inturned shoulder normally spaced from a~d opposing the outturned shoulder, said shoulders being located outwardly of said seal means; a heat fusible element located between and abutting said shoulders and holding them apart during normal operation of the valve and transmitting forces between said shoulders as such forces are developed by said actuating means to reciprocate the gate between valve closed and valve open positions but upon melting permitting said outturned shoulder to be moved toward said inturned shoulder to permit the stem to move outwardly and thereby move the gate from one of its valve open or closed positions to the other of said positions; the length of said element and hence the normal spacing of said shoulders being at least equal to the distance the valve stem must move the gate outwardly as aforesaid.
-4f ~
The invention is illustrated by way of example in the accompanying drawings wherein~
Fig. 1 is a view, in half-section~ of a gate valve embodying this invention' Fig. 2 is a ~artial cross-section of the upper portion of a gate valve showing another arrangement embodying this invention;
Fig. 3 is a view similar to Fig. 2 except it shows the invention applied to a non-rising stem type of valve; and Fig. 4 is still another view of an upper portion of valve showing another embodiment of the fusible element employed in the invention.
~ 4g~
~725~3 Referring to Fig. 1, there is shown a gate valve having a conventional body 10, bonnet 11, valve ele-ment 12 and seats 13 (only one of which is shown~.
Valve element 12 is connected to a valve stem 14 ex-tending from the bonnet and slidingly sealed thereto by means, for example, of a packing 15 and a packing nut 16.
The valve as thus far described is conventional and the various described elements can take other forms as long as a valve element is provided which can be moved between first and second position to control flow through the valve body and, also, there is provided a valve stem urged outwardly of the valve body and bonnet by pressure in the valve body acting over an area equivalent to that of the stem within the seal 15.
An actuating means is provided for reciprocating the valve element 12 and this actuating means can be functionally divided into three portions. In Fig. 1, the first portion is illustrated as a cap 17 fixed to the valve bonnet 11 by a series of cap screws 18.
The second portion of the actuating means is shown as a hollow cylindrical fusible element 19 having its upper end bearing against an inturned shoulder 20 carried by cap 17. The third portion of the actuat-ing means is illustrated as a nut 21 threaded to valve stem 14 and having an outturned shoulder 22 carrying a bearing 23 which in turn engages the lower end of fusible element 19.
A conventional handwheel 24 can be connected to nut 21 to rotate it to cause reciprocation of the valve stem and valve element.
With the foregoing arrangement, it can be seen that the thrust forces developed by valve stem 14 are transmitted across fusible element 19 to the cap 17 and thence to the bonnet 11. These thrust forces will consist primarily of the force developed by the pressure within the valve body acting across an area equal to that of the valve stem 14 within seal means 15.
When fusible element 19 is heated sufficiently, as by a fire in the vicinity, it will melt or fuse and the force generated by internal valve pressure acting on the valve stem will cause the melted mater-ial to be extruded out of openings 25 and 26 in cap 17. As the material is so extruded, the valve stem and valve element will move upwardlv a distance suf-- ficient that tapered shoulder 27 on the valve stem will engage a shoulder 28 on a bonnet to stop such outward movement. These respective shoulders are, of course, located so that they will engage after the valve element 12 has been moved to valve closing position as shown in Fig. 1. Also, the length of fusible element 19 should be at least equal to the distance the valve stem must travel to move the valve element from its open to its closed position.
As indicated above, high pressures within the valve body (e.g. 5000 psi) can act, if unrestrained, to cause the valve stem to slam violently against the :~172543 bonnet. In accordance with one aspect of this inven-tion, this is prevented by selecting the number and size of openings 25 and 26 to be such that the melted fusible material is extruded therefrom at a rate which is sufficiently low that the outward movement of the valve stem is dampened and the impact of shoulder 27 on the valve stem against shoulder 28 on the bonnet is of an acceptable magnitude.
Referring now to Fig. 2, the arrangement is simi-lar to that shown in Fig. 1 except that the actuator is designed to accomodate a rotating rising stem type of valve as contrasted to the non-rotating rising stem type of valve of Fig. 1. Elements in Fig. 2 corresponding to the elements of Fig. 1 have been numbered with like numbers with the su~fix "a" being added.
In the actuating means of Fig. 2, the nut 21A
does not rotate and is held against rotation by a pin 29 engaging a radial slot 30 in outturned shoulder 22A. Again, the thrust forces exerted by valve stem 14A are transmitted via nut 21A across fusible ele-ment 19A to cap 17A and thence to the bonnet llA.
Thus the valve is susceptible of operation between open and closed positions by simply rotating hand-wheel 24A. However, when the fusible element l9A
melts, the pressure internally of the valve will again force the valve stem upwardly to close the valve. Of course, fusible element l9A is made long enough so that when it is melted, the valve stem can move the valve element to its closed position.
~L17Z543 Fig. 3 shows yet another arrangement of an actua-ting means wherein valve stem 14B is threaded to nut 21B which is sealed to the bonnet by seal 15B. The thrust forces of valve stem 148 are transmitted by nut 21B to the fusible element l9B and thence via cap 17B to the bonnet llB. Reciprocation of the valve stem 14B is had by rotating handwheel 24B which in turn rotates nut 21B. Endwise movement of the nut is prevented by capturing shoulder 22B between bearings 23B and 35. The operating principle of the actuating means of Fig. 3 is the same as the other actuating means in that upon melting of the fusible element l9B, the nut and the valve stem are moved outwardly under the influence of pressure within the valve body as the fusible element l9B is melted. Here again 5 the rate of outward movement is controlled by the number and size of openings 25B in the cap. Also, the length of shaft 21B below, packing 15B is longer than the distance the shaft will move outward upon melting of the fusible element.
Referring to Fig. 4, there is shown an actuating means for a rising stem type of valve permitting relatively rapid movement of the valve stem upon melting of the fusible element. In this illustra-tion, the first portion of the actuating means com-prises the sleeve 50 mounted for rotation within the cap 51 by bearings 52 and 53 which capture outturned flange 54 therebetween. The hub of 55 of the hand-wheel 24C is also a part of the first portion and bears against fusible element 21C. The latter, of ~172543 course, is the second portion of the actuataing means. The third portion of the actuating means is the threaded upper end 56 of valve stem 14C which has a threaded connection to the fusible element.
With this arrangement, it will be seen that rota-tion of the handwheel will also rotate cap 57 and fusible element 21C to cause the latter to recipro-cate the valve stem. The thrust forces involved in reciprocating the valve stem are transmitted from the latter to the fusible element, then to cap 57, hub 55, sleeve 50 and cap 51 to bonnet llC.
When a fire or other elevated temperature condi-tion heats the fusible element 21C, it will loose its compressive strength and resistance to shear to a point where the outwardly directed force on the valve stem will cause the fusible element to shear in the vicinity of line 58. As a result, the valve stem can move rapidly upwardly carrying with it the sheared off plug of material still engaging the threads of the valve stem. This latter engagement prevents the sheared plug from acting as a projectile.
It will be noted in Fig. 4 that the fusible ele-ment has a conical outer surface 59 mating with a corresponding conical surface 60 on the inside of cap 57. As the valve stem applies an upward force against the fusible element, there will be a wedging action due to the conical arrangement to cause the fusible element to be thrust into tighter engagment with the threads on the valve stem. As a result, if the material or the fusible element has any cold flow 1~72543 properties, such can be accomodated while maintaining the fusible element in proper threaded connection to the valve stem.
In general, the fusible elements of this inventin can be made from materials which have physical pro-pe~ties suitable for undergoing the stresses and strains inherent to the normal operation of the valve. In addition, such material should have a softenin~ or melting point which will permit the valve to be closed when the temperature in the vicin-ity of the actuating mechanism reaches a level selec-ted by the designer of the valve. Ordinarily this level will be temperature within the range of 300 to 400F for ambient service of the valve but can be higher or lower. An example of a preferred of one of such materials is an acetal resin marketed under the trade name Delrin*. Other materials which can be used are nylon-6/6 marketed under the name Zytel, a poly-carbonate marketed under the name Lexan, Noryl which is a modified polyelyphene oxide and Texin ~hich is a polyurethane. Also, there are a family of lower melting point metal alloys which can be used inclu-ding 30/7û bar solder, Woods metal, etc.
* Trade Marks of E.I. du Pont de Nemours & Co.
Trade Mark of General Electric Company
This invention relates to a valve which in normal operation can be moved between open and closed posi-tions but which, when exposed to an selected high temperature level, will automatically be moved to a selected one of open or closed positions.
In many instances, it would be desirable to uti-lize a valve which, under normal circumstances, could be readily opened and closed to perform its normal valving function, but upon exposure of such valve to excessively high temperatures, such as in a fire, the valve would actuate to a selected one of open or closed positions. For example, such a valve could be used in refineries, chemical plants and the like as well as in christmas trees and flow lines in pro-ducing oil and gas wells to be automatically closed in the event of fire as a safety precaution and to prevent the fluid normally flowing through such valves from further feeding the fire. Such heat sen-sitive valves would thus "fail" to closed position.
On the other hand, there may be instances where it would be desired for the valve to "fail" to open position in the event of fire. For example, it might be desirable to vent fluid to a flare in the event of a fire. As indicated, with either type of valve, it would be desirable to be able to utilize the valve as a normal valve during day to day operations in the sense that the valve could be readily opened and closed at will.
~ ' ~72543 Many valves have been proposed which contain a fusible element which will cause some sort of res-ponse when exposed to a temperature sufficient to cause the element to fuse or melt. In one such type of valve, the fusible element continuously maintains the valve in either open or closed position until exposed to the elevated temperature at which time the valve will move to its other position. This type of valve can not be normally operated between open and closed positions but remains in one position until exposed to the elevated temperature. Another such type of valve employs a fusible element in such a manner that the valve can normally be moved between open and closed positions but, when the fusible ele-ment melts, the valve can fail only to open posi-tion. This type of valve is illustrated in U.S.
Patent No. 3,618,627 to Wagner. In addition, the fusible element as shown in the Wanger patent is lo-cated in the interior of the valve and the latter must be dismantled in order to replace the fusible element.
A very significant problem encountered in design-ing valves having the desired characteristics men-tioned above is to provide a fail safe operation which does not involve a portion of the valve becoming a "projectile" when the fusible element melts. Illustrative of this problem is the valve shown in U.S. Patent No. 3,842,854 to Wicke. In the Wicke patent, a valve operator is shown which becomes disengaged from the valve upon melting of a fusible ~72543 member. When such a valve is used in reasonably high pressure operations, e.g. 5000 psi, line pressure acting across the main valve stem will cause it to move abruptly to closed valve position when the operator becomes disconnected. This movement is so abrupt and so forceful that it causes the operator to become a projectile in effect, so that it will travel several tens of feet before it comes to rest. Ob-viously, this can be extremely hazardous.
To further il]ustrate the forces involved when high line pressures act to move a gate valve to closed posltion without any restraint on such move-ment, it has been observed that these forces can actually cause the valve bonnet to be torn from the main valve body when the gate slams against the bonnet.
It is an object of this invention to provide a heat sensitive valve operable to be moved between open and closed positions during normal operations and, upon being exposed to excessive temperatures, being operable to automatically move to the closed position or, depending upon the design of the valve element, to the open position.
Another object is to provide such a valve which, upon being exposed to excessive temperature, moves to one position under the influence of line pressure without producing any pieces or mechanisms which could act as projectiles and present a hazard to nearby personnel and equipment.
1~7~543 Another object i5 to provide such a valve wherein the fusible element is arranged in such a manner as to dampen the movement of the valve element and prevent it from slamming against the valve body or bonnet with excessive force.
Another object is to provide such a valve wherein the fusible element is exterior of the valving mechanism per se so that the element can be readily replaced and so that the valving mechanism can act in its normal manner upon melting of the fusible element.
Another object is to provide such a valve which is constructed so that after melting of the fusible element and movement of the valve to its fail safe position, it will be readily apparent to an observer that the valve is in such posltlon .
Other objects, advantages and features of the invention will be apparent to one skilled in the art upon a consideration of the written specification, the claims and the attached drawings.
In one aspect of the present invention there is provided a gate valve comprising a valve body having a gate valve comprising a valve body having inlet and outlet ends with means at each of said ends for connecting the valve to flow conduits, a flowway between such ends; a chamber intersecting the flowway and opening to one side of the valve body; a bonnet sealably connected to the valve body and having a bore there-through aligned with the chamber opening; a pair of annular spaced apart seats opposing each other and each having an opening therethrough coaxial with said flowway; a gate having parallel outwardly facing seating surfaces disposed between said seats at all times and reciprocal therebetween, said gate having an imperforate portion positionable between the seats and across the flowway to prevent flow therethrough when the ~17Z543 gate is moved to valve closed position and also having a port therethrough to be brought into alignment with the seats and the flowway to permit flow therethrough when the gate is in valve open position; actuating means for moving the gate between said valve closed and open positions including a valve stem attached to the gate and extending through the bore of the bonnet to the exterior of the bonnet; seal means between the stem and bonnet permitting movement of the stem while pre-venting escape of fluids from the bonnet; means for moving the stem outwardly consisting of the stem having an inner end exposed to line pressure within the valve body and an outer end exposed to atmospheric pressure exteriorly of the valve body such that a differential pressure effectively acts on the cross-sectional area of the stem within the seal means to provide the sole force to urge the stem outwardly of the valve body; said actuating means including a heat fusible element located outwardly of said seal means and disposed between opposing shoulders on the bonnet and the stem to transmit force developed by said actuating means to reciprocate the gate between valve closed and valve open positions but upon melting, being displaced by the stem being moved outwardly by said differential pressure so that said differential pressure will act on the stem to move it outwardly a distance that said gate will be moved fully from one of its valve closed and open positions to the other of such positions, said fusible element having a length at least equal to the distance said stem must move outwardly said distance.
In a further aspect of the present invention there is provided a heat sensitive valve comprising a valve body having a flowway therethrough and means at each end of the flowway for connecting the valve to flow conduits; a bonnet connected to the valve body and having a bore therethrough -4a-,,~, , ....
~ ~7Z543 communicating with said flowway, a pair of spaced apart seats in said body surrounding the flowway, a gate having outwardly facing parallel seating surfaces on either side thereof for simultaneous sliding contact with said seats respectively, said gate also having an imperforate portion positionable between the seats across the flowway to prevent flow therethrough when the gate is moved to valve closed position and also having a port therethrough to be brought into axial alignment with the seats and with the flowway to permit flow therethrough when the gate is in valve open position, a valve stem attached to the gate and extending through the bore oft~ bonnet to the exterior of the bonnet, said stem including a first internally thread hollow portion and a second externally threaded portion mating with said first portion so that upon relative rotation of the first and second stem portions, the second portion is caused to reciprocate the gate between valve open and valve closed positions; seal means between the stem and bonnet permitting movement of the stem while preventing escape of fluids from the bonnet, means for moving the stem outwardly consisting of the stem having an inner and exposed to line pressure wit~in the valve body and an outer end exposed to atmospheric pressure exteriorly of the valve body such that a differential pressure effectively acts on the cross-sectional area of the stem within the seal means to provide the sole force to urge stem outwardly of the valve body, a heat fusible e~ement connected between the bonnet and said first stem portion to normally transmit force developed during reciprocation of the gate between valve open and valve closed positions but upon melting, being displaced by the stem as the latter is moved outwardly by said differential pressure so that when said gate is in its one position as hereinafter defined said pressure differential will act on - 4b -~L~72543 the stem to move it outwardly a sufficient distance that said gate will be moved fully from one of its valve closed and valve open positions to the other end of such positions, said bonnet having a space therein around said first stem portion of sufficient magnitude such that, when said fusible element is melted, both the first and second stem portions are free to move outwardly said sufficient distance.
In a further a~spect of the present invention there is provided a gate valve comprising a valve body having inlet and outlet ends with means at each of said ends for connecting the valve to flow conduits; a flowway between such ends; a chamber intersecting the flowway and opening to one side of the valve body; a bonnet sealably connected to the valve body and having a bore therethrough aligned with the chamber open-ing; a pair of annular spaced apart seats opposing each other and each having an opening therethrough coaxial with said flowway; a gate having parallel outwardly facing seating surfaces disposed between said seats at all times and reciprocal therebetween, said gate having an imperforate portion positionable between the seats and across the flowway to prevent flow therethrough when the gate is moved to valve closed position and also having a port therethrough to be brought into alignment with the seats and the flowway to permit flow therethrough when the gate is in valve open position; actuating means for moving the gate between said valve closing and open positions including a valve stem attached to the gate and extending through the bore of the bonnet to the exterior of the bonnet; seal means between the stem and bonnet permitting movement of the stem while preventing escape of fluids from the bonnet; means for urging the stem outwardly of the valve body consisting of the stem having an inner end exposed to line pressure within the valve -4c-:.
~17Z543 body and an outer end exposed to atmospheric pressure exteriorly of the valve body such that a differential pressure effectively acts on the cross-sectional area of the stem within the seal means to provide the necessar~ force for urging the stem outwardly of the valve body said actuating means includ-ing a first shoulder on the bonnet, a second shoulder opposing the first shoulder and connected to the stem so that said differential pressure urging the stem outwardly of the body also urges the second shoulder towards the first shoulder, a heat fusible element disposed between said first and second shoulder and normally preventing the second shoulder from moving toward the first shoulder during normal opening and closing of the valve but upon melting being displaced from between said first and second shoulders to allow the stem to be moved outwardly a predetermined distance to move the second shoulder toward the first shoulder and in so doing to move the gate fully from one of its valve open or closed positions to the other of said positions, said fusible element having a length at least equal to said predetermined distance-In a further aspect of the present invention there is provided a heat sensitive valve comprising a valve body having a flowway therethrough and means at each end of the flowway for connecting the valve to flow conduits; a bonnet connected to the valve body and having a bore therethrough communicating with said flowway, a pair of spaced apart seats in said body surrounding the flowway; a gate having outwardly facing parallel seating surfaces on either side thereof for simultaneous sliding contact with said seats respectively, said gate ~lso having an imperforate portion positionable between the seats across the flow-away to prevent flow therethrough when the gate is moved to valve - 4d-~ ., , ~ , : L172S4~
closed position and also having a port therethrough to be brought into axial alignment with the seats and with the flowway to permit flow therethrough when the gate is in valve open position; a valve stem attached to the gate and extending through the bore of the bonnet to the exterior of the bonnet, said stem including a first internally threaded hollow portion having an outturned flange and a second externally threaded portion mating with said first portion so that upon relative rotation of the first and second stem portions, the second portion is caused to reciprocate the gate between valve open and valve closed positions; seal means between the st m and bonnet permitting movement of the stem while preventing escape of fluids From the bonnet; means for moving the stem outwardly consisting of the stem having an inner end exposed to line pressure within the valve body and an outer end exposed to atmospheric pressure exteriorly of the valve body such that a differential pressure effectively acts on the cross-sectional area of the stem within the seal means to provide the sole foroe to urge stem outwardly of the valve body; said bonnet having an inturned flange opposing said outturned flange and spaced therefrom a distance at least as great as that which the gate moves between is fully open and fully closed positions; a heat fusible element extending between said flanges to normally transmit foroe s developed during reciprocation of the gate between valve open and valve closed positions but upon melting, being displaced by the stem as the latter is moved outwardly by said differential pressure so that when said gate is in its one position as hereinafter defined, said pressure differential will act on the stem to move it outwardly a sufficient distance that said gate will be moved fully from one of its valve closed and valve open positions to the other of such positi~ns.
- 4e -1~72543 In a further aspect of the present invention there is provided a gate valve comprising a valve body having inlet and outlet ends with means at each of said ends for connecting the valve to flow conduits; a flowway between such ends; a chamber intersect1ng the flowway and opening to one side of the valve body; a bonnet sealably connected to the valve body and having a bore aligned with the chamber opening; a seat surrounding the flowway; a gate seatable on said seat to prevent flow through said flowway when the gate is moved to valve closed position and being movable from said seat to permit flow through said flowway when the gate is in valve open position, seal means between the stem and bonnet permitting movement of the stem while preventing escape of fluids from the bonnet; actuating means for moving the gate between said valve closed and open positions including a valve stem attached to the gate and extending through the bore of the bonnet to the exterio~ of the bonnet and having an outturned shoulder thereon; said bonnet having an inturned shoulder normally spaced from a~d opposing the outturned shoulder, said shoulders being located outwardly of said seal means; a heat fusible element located between and abutting said shoulders and holding them apart during normal operation of the valve and transmitting forces between said shoulders as such forces are developed by said actuating means to reciprocate the gate between valve closed and valve open positions but upon melting permitting said outturned shoulder to be moved toward said inturned shoulder to permit the stem to move outwardly and thereby move the gate from one of its valve open or closed positions to the other of said positions; the length of said element and hence the normal spacing of said shoulders being at least equal to the distance the valve stem must move the gate outwardly as aforesaid.
-4f ~
The invention is illustrated by way of example in the accompanying drawings wherein~
Fig. 1 is a view, in half-section~ of a gate valve embodying this invention' Fig. 2 is a ~artial cross-section of the upper portion of a gate valve showing another arrangement embodying this invention;
Fig. 3 is a view similar to Fig. 2 except it shows the invention applied to a non-rising stem type of valve; and Fig. 4 is still another view of an upper portion of valve showing another embodiment of the fusible element employed in the invention.
~ 4g~
~725~3 Referring to Fig. 1, there is shown a gate valve having a conventional body 10, bonnet 11, valve ele-ment 12 and seats 13 (only one of which is shown~.
Valve element 12 is connected to a valve stem 14 ex-tending from the bonnet and slidingly sealed thereto by means, for example, of a packing 15 and a packing nut 16.
The valve as thus far described is conventional and the various described elements can take other forms as long as a valve element is provided which can be moved between first and second position to control flow through the valve body and, also, there is provided a valve stem urged outwardly of the valve body and bonnet by pressure in the valve body acting over an area equivalent to that of the stem within the seal 15.
An actuating means is provided for reciprocating the valve element 12 and this actuating means can be functionally divided into three portions. In Fig. 1, the first portion is illustrated as a cap 17 fixed to the valve bonnet 11 by a series of cap screws 18.
The second portion of the actuating means is shown as a hollow cylindrical fusible element 19 having its upper end bearing against an inturned shoulder 20 carried by cap 17. The third portion of the actuat-ing means is illustrated as a nut 21 threaded to valve stem 14 and having an outturned shoulder 22 carrying a bearing 23 which in turn engages the lower end of fusible element 19.
A conventional handwheel 24 can be connected to nut 21 to rotate it to cause reciprocation of the valve stem and valve element.
With the foregoing arrangement, it can be seen that the thrust forces developed by valve stem 14 are transmitted across fusible element 19 to the cap 17 and thence to the bonnet 11. These thrust forces will consist primarily of the force developed by the pressure within the valve body acting across an area equal to that of the valve stem 14 within seal means 15.
When fusible element 19 is heated sufficiently, as by a fire in the vicinity, it will melt or fuse and the force generated by internal valve pressure acting on the valve stem will cause the melted mater-ial to be extruded out of openings 25 and 26 in cap 17. As the material is so extruded, the valve stem and valve element will move upwardlv a distance suf-- ficient that tapered shoulder 27 on the valve stem will engage a shoulder 28 on a bonnet to stop such outward movement. These respective shoulders are, of course, located so that they will engage after the valve element 12 has been moved to valve closing position as shown in Fig. 1. Also, the length of fusible element 19 should be at least equal to the distance the valve stem must travel to move the valve element from its open to its closed position.
As indicated above, high pressures within the valve body (e.g. 5000 psi) can act, if unrestrained, to cause the valve stem to slam violently against the :~172543 bonnet. In accordance with one aspect of this inven-tion, this is prevented by selecting the number and size of openings 25 and 26 to be such that the melted fusible material is extruded therefrom at a rate which is sufficiently low that the outward movement of the valve stem is dampened and the impact of shoulder 27 on the valve stem against shoulder 28 on the bonnet is of an acceptable magnitude.
Referring now to Fig. 2, the arrangement is simi-lar to that shown in Fig. 1 except that the actuator is designed to accomodate a rotating rising stem type of valve as contrasted to the non-rotating rising stem type of valve of Fig. 1. Elements in Fig. 2 corresponding to the elements of Fig. 1 have been numbered with like numbers with the su~fix "a" being added.
In the actuating means of Fig. 2, the nut 21A
does not rotate and is held against rotation by a pin 29 engaging a radial slot 30 in outturned shoulder 22A. Again, the thrust forces exerted by valve stem 14A are transmitted via nut 21A across fusible ele-ment 19A to cap 17A and thence to the bonnet llA.
Thus the valve is susceptible of operation between open and closed positions by simply rotating hand-wheel 24A. However, when the fusible element l9A
melts, the pressure internally of the valve will again force the valve stem upwardly to close the valve. Of course, fusible element l9A is made long enough so that when it is melted, the valve stem can move the valve element to its closed position.
~L17Z543 Fig. 3 shows yet another arrangement of an actua-ting means wherein valve stem 14B is threaded to nut 21B which is sealed to the bonnet by seal 15B. The thrust forces of valve stem 148 are transmitted by nut 21B to the fusible element l9B and thence via cap 17B to the bonnet llB. Reciprocation of the valve stem 14B is had by rotating handwheel 24B which in turn rotates nut 21B. Endwise movement of the nut is prevented by capturing shoulder 22B between bearings 23B and 35. The operating principle of the actuating means of Fig. 3 is the same as the other actuating means in that upon melting of the fusible element l9B, the nut and the valve stem are moved outwardly under the influence of pressure within the valve body as the fusible element l9B is melted. Here again 5 the rate of outward movement is controlled by the number and size of openings 25B in the cap. Also, the length of shaft 21B below, packing 15B is longer than the distance the shaft will move outward upon melting of the fusible element.
Referring to Fig. 4, there is shown an actuating means for a rising stem type of valve permitting relatively rapid movement of the valve stem upon melting of the fusible element. In this illustra-tion, the first portion of the actuating means com-prises the sleeve 50 mounted for rotation within the cap 51 by bearings 52 and 53 which capture outturned flange 54 therebetween. The hub of 55 of the hand-wheel 24C is also a part of the first portion and bears against fusible element 21C. The latter, of ~172543 course, is the second portion of the actuataing means. The third portion of the actuating means is the threaded upper end 56 of valve stem 14C which has a threaded connection to the fusible element.
With this arrangement, it will be seen that rota-tion of the handwheel will also rotate cap 57 and fusible element 21C to cause the latter to recipro-cate the valve stem. The thrust forces involved in reciprocating the valve stem are transmitted from the latter to the fusible element, then to cap 57, hub 55, sleeve 50 and cap 51 to bonnet llC.
When a fire or other elevated temperature condi-tion heats the fusible element 21C, it will loose its compressive strength and resistance to shear to a point where the outwardly directed force on the valve stem will cause the fusible element to shear in the vicinity of line 58. As a result, the valve stem can move rapidly upwardly carrying with it the sheared off plug of material still engaging the threads of the valve stem. This latter engagement prevents the sheared plug from acting as a projectile.
It will be noted in Fig. 4 that the fusible ele-ment has a conical outer surface 59 mating with a corresponding conical surface 60 on the inside of cap 57. As the valve stem applies an upward force against the fusible element, there will be a wedging action due to the conical arrangement to cause the fusible element to be thrust into tighter engagment with the threads on the valve stem. As a result, if the material or the fusible element has any cold flow 1~72543 properties, such can be accomodated while maintaining the fusible element in proper threaded connection to the valve stem.
In general, the fusible elements of this inventin can be made from materials which have physical pro-pe~ties suitable for undergoing the stresses and strains inherent to the normal operation of the valve. In addition, such material should have a softenin~ or melting point which will permit the valve to be closed when the temperature in the vicin-ity of the actuating mechanism reaches a level selec-ted by the designer of the valve. Ordinarily this level will be temperature within the range of 300 to 400F for ambient service of the valve but can be higher or lower. An example of a preferred of one of such materials is an acetal resin marketed under the trade name Delrin*. Other materials which can be used are nylon-6/6 marketed under the name Zytel, a poly-carbonate marketed under the name Lexan, Noryl which is a modified polyelyphene oxide and Texin ~hich is a polyurethane. Also, there are a family of lower melting point metal alloys which can be used inclu-ding 30/7û bar solder, Woods metal, etc.
* Trade Marks of E.I. du Pont de Nemours & Co.
Trade Mark of General Electric Company
Claims (8)
1. A gate valve comprising a valve body having inlet and outlet ends with means at each of said ends for connecting the valve to flow conduits, a flowway between such ends; a chamber intersecting the flowway and opening to one side of the valve body; a bonnet sealably connected to the valve body and having a bore therethrough aligned with the chamber opening; a pair of annular spaced apart seats opposing each other and each having an opening therethrough coaxial with said flowway;
a gate having parallel outwardly facing seating surfaces disposed between said seats at all times and reciprocal therebetween, said gate having an imperforate portion positionable between the seats and across the flowway to prevent flow therethrough when the gate is moved to valve closed position and also having a port therethrough to be brought into alignment with the seats and the flowway to permit flow therethrough when the gate is in valve open position; actuating means for moving the gate between said valve closed and open positions including a valve stem attached to the gate and extending through the bore of the bonnet to the exterior of the bonnet; seal means between the stem and bonnet permitting movement of the stem while preventing escape of fluids from the bonnet; means for moving the stem outwardly consisting of the stem having an inner end exposed to line pressure within the valve body and an outer end exposed to atmospheric pressure exteriorly of the valve body such that a differential pressure effectively acts on the cross-sectional area of the stem within the seal means to provide the sole force to urge the stem outwardly of the valve body; said actuating means including a heat fusible element located outwardly of said seal means and disposed between opposing shoulders on the bonnet and the stem to transmit force developed by said actuating means to reciprocate the gate between valve closed and valve open positions but upon melting, being displaced by the stem being moved outwardly by said differential pressure so that said differential pressure will act on the stem to move it outwardly a distance that said gate will be moved fully from one of its valve closed and valve open positions to the other of such positions, said fusible element having a length at least equal to the distance said stem must move outwardly said distance.
a gate having parallel outwardly facing seating surfaces disposed between said seats at all times and reciprocal therebetween, said gate having an imperforate portion positionable between the seats and across the flowway to prevent flow therethrough when the gate is moved to valve closed position and also having a port therethrough to be brought into alignment with the seats and the flowway to permit flow therethrough when the gate is in valve open position; actuating means for moving the gate between said valve closed and open positions including a valve stem attached to the gate and extending through the bore of the bonnet to the exterior of the bonnet; seal means between the stem and bonnet permitting movement of the stem while preventing escape of fluids from the bonnet; means for moving the stem outwardly consisting of the stem having an inner end exposed to line pressure within the valve body and an outer end exposed to atmospheric pressure exteriorly of the valve body such that a differential pressure effectively acts on the cross-sectional area of the stem within the seal means to provide the sole force to urge the stem outwardly of the valve body; said actuating means including a heat fusible element located outwardly of said seal means and disposed between opposing shoulders on the bonnet and the stem to transmit force developed by said actuating means to reciprocate the gate between valve closed and valve open positions but upon melting, being displaced by the stem being moved outwardly by said differential pressure so that said differential pressure will act on the stem to move it outwardly a distance that said gate will be moved fully from one of its valve closed and valve open positions to the other of such positions, said fusible element having a length at least equal to the distance said stem must move outwardly said distance.
2. The valve of claim 1 wherein said fusible element is an annular cylinder disposed around said stem, said bonnet including a cap surrounding said fusible element, said cap and stem each having a shoulder abutting the ends of said fusible element and the cap having a port therethrough through which the material of the fusible element is extruded when melted.
3. A heat sensitive valve comprising a valve body having a flowway therethrough and means at each end of the flowway for connecting the valve to flow conduits; a bonnet connected to the valve body and having a bore therethrough communicating with said flowway; a pair of spaced apart seats in said body surrounding the flowway; a gate having outwardly facing parallel seating surfaces on either side thereof for simultaneous sliding contact with said seats respectively, said gate also having an imperforate portion positionable between the seats across the flowway to prevent flow therethrough when the gate is moved to valve closed position and also having a port therethrough to be brought into axial alignment with the seats and with the flowway to permit flow therethrough when the gate is in valve open position; a valve stem attached to the gate and extending through the bore of the bonnet to the exterior of the bonnet, said stem including a first internally thread hollow portion and a second externally threaded portion mating with said first portion so that upon relative rotation of the first and second stem portions, the second portion is caused to reciprocate the gate between valve open and valve closed positions; seal means between the stem and bonnet permitting movement of the stem while preventing escape of fluids from the bonnet; means for moving the stem outwardly consisting of the stem having an inner end exposed to line pressure within the valve body and an outer end exposed to atmospheric pressure exteriorly of the valve body such that a differential pressure effectively acts on the cross-sectional area of the stem within the seal means to provide the sole force to urge stem outwardly of the valve body; a heat fusible element connected between the bonnet and said first stem portion to normally transmit force developed during reciprocation of the gate between valve open and valve closed positions but upon melting, being displaced by the stem as the latter is moved outwardly by said differential pressure so that when said gate is in its one position as hereinafter defined said pressure differential will act on the stem to move it outwardly a sufficient distance that said gate will be moved fully from one of its valve closed and valve open positions to the other end of such positions, said bonnet having a space therein around said first stem portion of sufficient magnitude such that, when said fusible element is melted, both the first and second stem portions are free to move outwardly said sufficient distance.
4. The valve of Claim 3 wherein the hollow portion has an outturned annular flange and the bonnet has an inturned annular flange and wherein said fusible element is an annular cylindrical element disposed between said flanges, the length of the fusible element between said flanges being at least as great as said sufficient distance.
5. A gate valve comprising a valve body having inlet and outlet ends with means at each of said ends for connecting the valve to flow conduits; a flowway between such ends; a chamber intersecting the flowway and opening to one side of the valve body; a bonnet sealably connected to the valve body and having a bore therethrough aligned with the chamber opening; a pair of annular spaced apart seats opposing each other and each having an opening therethrough coaxial with said flowway;
a gate having parallel outwardly facing seating surfaces disposed between said seats at all times and reciprocal therebetween, said gate having an imperforate portion positionable between the seats and across the flowway to prevent flow therethrough when the gate is moved to valve closed position and also having a port therethrough to be brought into alignment with the seats and the flowway to permit flow therethrough when the gate is in valve open position; actuating means for moving the gate between said valve closing and open positions including a valve stem attached to the gate and extending through the bore of the bonnet to the exterior of the bonnet; seal means between the stem and bonnet permitting movement of the stem while preventing escape of fluids from the bonnet; means for urging the stem outwardly of the valve body consisting of the stem having an inner end exposed to line pressure within the valve body and an outer end exposed to atmospheric pressure exteriorly of the valve body such that a differential pressure effectively acts on the cross-sectional area of the stem within the seal means to provide the necessary force for urging the stem outwardly of the valve body; said actuating means including a first shoulder on the bonnet, a second shoulder opposing the first shoulder and connected to the stem so that said differential pressure urging the stem outwardly of the body also urges the second shoulder towards the first shoulder, a heat fusible element disposed between said first and second shoulder and normally preventing the second shoulder from moving toward the first shoulder during normal opening and closing of the valve but upon melting being displaced from between said first and second shoulders to allow the stem to be moved outwardly a predetermined distance to move the second shoulder toward the first shoulder and in so doing to move the gate fully from one of its valve open or closed positions to the other of said positions, said fusible element having a length at least equal to said predetermined distance.
a gate having parallel outwardly facing seating surfaces disposed between said seats at all times and reciprocal therebetween, said gate having an imperforate portion positionable between the seats and across the flowway to prevent flow therethrough when the gate is moved to valve closed position and also having a port therethrough to be brought into alignment with the seats and the flowway to permit flow therethrough when the gate is in valve open position; actuating means for moving the gate between said valve closing and open positions including a valve stem attached to the gate and extending through the bore of the bonnet to the exterior of the bonnet; seal means between the stem and bonnet permitting movement of the stem while preventing escape of fluids from the bonnet; means for urging the stem outwardly of the valve body consisting of the stem having an inner end exposed to line pressure within the valve body and an outer end exposed to atmospheric pressure exteriorly of the valve body such that a differential pressure effectively acts on the cross-sectional area of the stem within the seal means to provide the necessary force for urging the stem outwardly of the valve body; said actuating means including a first shoulder on the bonnet, a second shoulder opposing the first shoulder and connected to the stem so that said differential pressure urging the stem outwardly of the body also urges the second shoulder towards the first shoulder, a heat fusible element disposed between said first and second shoulder and normally preventing the second shoulder from moving toward the first shoulder during normal opening and closing of the valve but upon melting being displaced from between said first and second shoulders to allow the stem to be moved outwardly a predetermined distance to move the second shoulder toward the first shoulder and in so doing to move the gate fully from one of its valve open or closed positions to the other of said positions, said fusible element having a length at least equal to said predetermined distance.
6. The valve of claim 5 wherein said fusible element is an annular cylinder disposed around said stem, said bonnet including a cap surrounding and enclosing said fusible element to shield it from a fire, said cap and stem each having a shoulder abutting the ends of said fusible element and the cap having a port therethrough through which the material of the fusible element is extruded when melted.
7. A heat sensitive valve comprising a valve body having a flowway therethrough and means at each end of the flowway for connecting the valve to flow conduits; a bonnet connected to the valve body and having a bore therethrough communicating with said flowway; a pair of spaced apart seats in said body surrounding the flowway; a gate having outwardly facing parallel seating surfaces on either side thereof for simultaneous sliding contact with said seats respectively, said gate also having an imperforate portion positionable between the seats across the flowway to prevent flow therethrough when the gate is moved to valve closed position and also having a port therethrough to be brought into axial alignment with the seats and with the flowway to permit flow therethrough when the gate is in valve open position; a valve stem attached to the gate and extending through the bore of the bonnet to the exterior of the bonnet, said stem including a first internally threaded hollow portion having an outturned flange and a second externally threaded portion mating with said first portion so that upon relative rotation of the first and second stem portions, the second portion is caused to reciprocate the gate between valve open and valve closed positions; seal means between the stem and bonnet permitting movement of the stem while preventing escape of fluids from the bonnet; means for moving the stem outwardly consisting of the stem having an inner end exposed to line pressure within the valve body and an outer end exposed to atmospheric pressure exteriorly of the valve body such that a differential pressure effectively acts on the cross-sectional area of the stem within the seal means to provide the sole force to urge stem outwardly of the valve body; said bonnet having an inturned flange opposing said outturned flange and spaced therefrom a distance at least as great as that which the gate moves between is fully open and fully closed positions; a heat fusible element extending between said flanges to normally transmit forces developed during reciprocation of the gate between valve open and valve closed positions but upon melting, being displaced by the stem as the latter is moved outwardly by said differential pressure so that when said gate is in its one position as hereinafter defined, said pressure differential will act on the stem to move it outwardly a sufficient distance that said gate will be moved fully from one of its valve closed and valve open positions to the other of such positions.
8. A gate valve comprising a valve body having inlet and outlet ends with means at each of said ends for connecting the valve to flow conduits; a flowway between such ends; a chamber intersecting the flowway and opening to one side of the valve body; a bonnet sealably connected to the valve body and having a bore aligned with the chamber opening; a seat surrounding the flowway; a gate seatable on said seat to prevent flow through said flowway when the gate is moved to valve closed position and being movable from said seat to permit flow through said flowway when the gate is in valve open position; seal means between the stem and bonnet permitting movement of the stem while preventing escape of fluids from the bonnet; actuating means for moving the gate between said valve closed and open positions including a valve stem attached to the gate and extending through the bore of the bonnet to the exterior of the bonnet and having an outturned shoulder thereon; said bonnet having an inturned shoulder normally spaced from and opposing the outturned shoulder, said shoulders being located outwardly of said seal means; a heat fusible element located between and abutting said shoulders and holding them apart during normal operation of the valve and transmitting forces between said shoulders as such forces are developed by said actuating means to reciprocate the gate between valve closed and valve open positions but upon melting permitting said outturned shoulder to be moved toward said inturned shoulder to permit the stem to move outwardly and thereby move the gate from one of its valve open or closed positions to the other of said positions; the length of said element and hence the normal spacing of said shoulders being at least equal to the distance the valve stem must move the gate outwardly as aforesaid.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US17137280A | 1980-07-23 | 1980-07-23 | |
| US171,372 | 1980-07-23 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1172543A true CA1172543A (en) | 1984-08-14 |
Family
ID=22623495
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000381272A Expired CA1172543A (en) | 1980-07-23 | 1981-07-07 | Heat sensitive valve |
Country Status (10)
| Country | Link |
|---|---|
| JP (1) | JPS5747076A (en) |
| AT (1) | AT392678B (en) |
| BR (1) | BR8103905A (en) |
| CA (1) | CA1172543A (en) |
| DE (1) | DE3126134A1 (en) |
| FR (1) | FR2487474A1 (en) |
| GB (1) | GB2080496B (en) |
| IT (1) | IT1171383B (en) |
| MX (1) | MX153429A (en) |
| NL (1) | NL8102757A (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4568062A (en) * | 1983-03-07 | 1986-02-04 | Fmc Corporation | Fire-resistant gate valve |
| US4540012A (en) * | 1983-04-18 | 1985-09-10 | Gray Tool Company | Temperature sensitive valve bonnet assembly |
| US4505291A (en) * | 1983-08-11 | 1985-03-19 | Axelson, Inc. | Heat sensitive fire safe valve energy assist device |
| JPS61256075A (en) * | 1985-05-07 | 1986-11-13 | Japan Steel Works Ltd:The | Gate valve having anti-fire function |
| US7004445B2 (en) * | 2003-10-27 | 2006-02-28 | Safoco, Inc. | Mechanical override for a valve actuator |
Family Cites Families (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE1249612B (en) * | 1967-09-07 | |||
| US422583A (en) * | 1890-03-04 | Automatic valve for gas-service pipes | ||
| USRE20643E (en) * | 1938-02-01 | Safety device | ||
| US1532615A (en) * | 1924-02-29 | 1925-04-07 | Wills Edwin Cooper | Automatic cut-off and cut-in valve |
| US1949776A (en) * | 1933-04-06 | 1934-03-06 | Belknap Mfg Company | Heat responsive valve |
| US2035497A (en) * | 1934-06-12 | 1936-03-31 | Lynn H Morse | Valve |
| US2137685A (en) * | 1937-12-30 | 1938-11-22 | Daniel A Gillen | Double manual and automatic shutoff valve |
| GB919164A (en) * | 1959-05-27 | 1963-02-20 | R F Landon & Partners Ltd | Improvements in or relating to fluid control valves |
| GB1139462A (en) * | 1966-03-16 | 1969-01-08 | Michaelsen Hedensted Brdr | Improvements in or relating to fire safety valves for oil burning installations |
| US3618627A (en) * | 1969-10-29 | 1971-11-09 | William Wagner | Valve automatic pressure release means |
| US3842854A (en) * | 1973-04-16 | 1974-10-22 | Acf Ind Inc | Heat responsive safety device for manual gate valve operators |
-
1981
- 1981-05-28 GB GB8116238A patent/GB2080496B/en not_active Expired
- 1981-06-09 NL NL8102757A patent/NL8102757A/en not_active Application Discontinuation
- 1981-06-22 BR BR8103905A patent/BR8103905A/en unknown
- 1981-07-02 DE DE19813126134 patent/DE3126134A1/en active Granted
- 1981-07-07 CA CA000381272A patent/CA1172543A/en not_active Expired
- 1981-07-09 AT AT3028/81A patent/AT392678B/en active
- 1981-07-13 IT IT48891/81A patent/IT1171383B/en active
- 1981-07-15 JP JP56109521A patent/JPS5747076A/en active Granted
- 1981-07-22 FR FR8114274A patent/FR2487474A1/en active Granted
- 1981-07-22 MX MX188405A patent/MX153429A/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| FR2487474B1 (en) | 1984-10-26 |
| ATA302881A (en) | 1990-10-15 |
| DE3126134C2 (en) | 1991-01-10 |
| BR8103905A (en) | 1982-03-09 |
| IT1171383B (en) | 1987-06-10 |
| DE3126134A1 (en) | 1982-03-04 |
| MX153429A (en) | 1986-10-08 |
| JPS5747076A (en) | 1982-03-17 |
| GB2080496B (en) | 1984-03-28 |
| IT8148891A0 (en) | 1981-07-13 |
| JPH0362948B2 (en) | 1991-09-27 |
| FR2487474A1 (en) | 1982-01-29 |
| NL8102757A (en) | 1982-02-16 |
| GB2080496A (en) | 1982-02-03 |
| AT392678B (en) | 1991-05-27 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4421134A (en) | Heat sensitive gate valve | |
| US7004445B2 (en) | Mechanical override for a valve actuator | |
| DE19831283C1 (en) | Safety device for shutting off gas-bearing piping systems | |
| US3346234A (en) | Valve | |
| US4619434A (en) | Heat sensitive motor valve jack | |
| EP0247275B1 (en) | Fire resistant gate valve | |
| WO1994007063A1 (en) | Low-noise rotary control valve | |
| US4240455A (en) | Heat responsive back seat arrangement for valve operator with manual override | |
| CA1127500A (en) | Fire safe valve | |
| US5067510A (en) | Adjustable, fusible, manually operable valve lock-open assembly | |
| CA1172543A (en) | Heat sensitive valve | |
| US4658848A (en) | Heat responsive backseat for gate valves | |
| US4214600A (en) | Valve | |
| EP0225435B1 (en) | Heat sensitive valve | |
| US3877476A (en) | Heat actuated valve | |
| CA1221000A (en) | Fire responsive stem retention apparatus | |
| JPS61175375A (en) | Unilateral/bidirectional sluice valve | |
| US4245662A (en) | Heat responsive back seat arrangement for valve operator with fusible lock-out cap | |
| FI95501B (en) | Fire Closure Device | |
| EP0088077B1 (en) | Fire safe valve | |
| WO2010091291A2 (en) | Pressure-balanced control valves | |
| US4505291A (en) | Heat sensitive fire safe valve energy assist device | |
| WO1994027072A1 (en) | Safety devices | |
| CA1121792A (en) | Valve | |
| AU783558B2 (en) | Fire activated, fail safe, gate valve bonnet |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |