Abstract: Fire control valve through which flows flammable material, such as gas or liquid, includes exteriorly located, replaceable locking pin assembly having a locking pin for locking the valve member of the fire control valve in the open position to enable flow through the fire control valve, the locking pin assembly being also located out of the path of such flow and including a heat-meltable material that holds locking pin in locked position with the valve member and, upon being melted, enables release of locking pin from locked position; the fire control valve including a sealing arrangement to prevent escape of flammable material to atmosphere past valve member and locking pin assembly.

Abstract: A fire damper for impeding the spread of fire from the burning of plastic pipes inside a wall or floor structure. The fire damper is installed adjacent to only one side of an opening where the pipe penetrates the structure so that the damper can be added as a retrofit without disturbing the pipe. The damper comprises a base which can be easily mounted on a two by four or similar structural member, a disk-like gate, and a torsion spring. The gate is slightly larger in area than the opening for the pipe. The coil of the spring acts as a hinge connection between the gate and the base. One arm of the spring is fixed to the gate. The free end of the torsion spring is activated by rotating the gate toward the base and then pressing the base against the plastic pipe before securing the base permanently in place.

Abstract: An apparatus arranged to orient a closure cap over an entrance opening of a chimney stack to prevent a fire from projecting through the stack with the apparatus to include a spring-biased member and a fusible link permitting release of a plug member to secure the plug member within the chimney stack upon release of the fusible link.

Abstract: An improved firestop stack fitting assembly (10) for use in a building with a floor (22) and a ceiling (30) supported by a floor joist (36), is described. The fitting includes a flammable main conduit (12) mounted on a flammable pipe (18), provided with a non-flammable insert (20) mounted through an opening in the floor. An extension conduit (14) supports a non-flammable plug (40) which is released to fall into and seal off the sleeve and insert when a harness (42) is melted by heat from a fire burning below the ceiling of a lower story or burning in a joist space (28) between the ceiling and the floor to prevent the fire from spreading to an upper story above the floor through the insert. A tee fitting (150) can be optimally mounted in the joist space connected to a pipe (118) mounting an insert (120) and to drain pipe (162) and an extension conduit (164). The fitting assembly prevents the spread of fire and smoke through the insert and main conduit.

Abstract: A fire safety device for closing through-holes in floors and walls and for thus stopping the potential spread of fire and smoke in case of the occurrence of a fire, includes a section of conduit, a cup-shaped retainer spaced from the outside surface of the conduit section so as to define an annular space therebetween, the annular space containing a suitable and pre-measured quantity of intumescent material, and a floating floor below the intumescent material which, in the event of fire, will move inwardly to occupy the interior space previously occupied by the conduit section.

Abstract: An improved firestop fitting (10) which prevents the spread of smoke and fire through a wall (100, 110, 120) between rooms in a building is described. The fitting includes a thermally releasable plug (16) mounted in an extension conduit (14) from a main conduit (12) of the fitting which is activated by a fire to allow the plug to move into and block the main conduit. The fitting is particularly adapted for buildings where plastic pipe is used to carry fluid between rooms.

Abstract: A heat releasable weldment for a mechanical opening jack used in combination with fluid powered valve actuators to release said manual opening jack in the event of fire comprising grooved inner and outer members which cooperate to form a eutectic chamber, said inner and said outer members being retained in spaced relationship with each other by horizontal and vertical restraining members in cooperation with a fusable eutectic alloy which is poured into said eutectic chamber and allowed to solidify together and a method to field retrofit said weldment to a mechanical opening jack is presented.

Abstract: An actuator shaft heat-sensitive locking apparatus is disclosed comprising a cylindrical housing having an axial bore. A shaft link is provided in the bore and is adjustable to contact gate valve actuator shafts of varying lengths. Once adjusted, the shaft link is movable axially between a first position and a second position, allowing the actuator shaft to close the gate valve. There is also provided a means movably extending through the housing for partially blocking the bore and a fusible element slidably mounted in the bore between the shaft link and the means for partially blocking the bore. The fusible element has both a solid state and a heat responsive state. In its solid state, the fusible elemnt prevents movement of the shaft link by enaging the bore blocking means; in its heat responsive state, the fusible element allows movement of the shaft link between the first position and second position.

Abstract: A hydrocarbon monitoring valve which is operative to close whenever hydrocarbons are present in a fluid passing therethrough has a hollow hydrocarbon-sensitive canister mounted in a generally vertically disposed portion of a housing of the valve. The presence of hydrocarbons within fluid passing through the canister produces rapid deterioration of the canister, with the result that mechanical linkage coupled to the canister acts to close a valve element within a generally horizontally disposed portion of the valve adjacent an inlet, thereby shutting the valve from further flow of fluid therethrough.

Abstract: As a coupling is connected, an improved heat fusible actuator member in a plug assembly moves a value member in a socket assembly from a closed position to an open position against the influence of a biasing spring. When the coupling is exposed to excessive heat, the one piece actuator member fuses and is deformed under the influence of force applied against the actuator member by the valve member to enable the valve member to close. In one embodiment, the actuator member includes a cylindrical sleeve which is resiliently compressible to enable retaining lugs on an inner end of the sleeve to engage in an annular retaining surface on a metal plug body. At the same time, an annular rim on an outer end of the sleeve engages a circular outer end surface of the plug body. A bridging member extends across the fluid passage through the sleeve and is engaged by the valve member.

Abstract: A connector set adapted for releasably connecting a gas conduit from a gas appliance or the like to a gas line to provide gas to the appliance. The connector set comprises a nipple adapted to be connected to the gas conduit and a receptacle adapted to be connected to the gas line. The receptacle has a socket adapted to receive the nipple, and first and second valves. The valves are each operable between an open position and a closed position and arranged so that gas can pass from the gas line to the socket only when both valves are in their open positions. The receptacle further includes a mechanism for operating the second valve as the first valve is operated so that the second valve opens when the first valve opens and closes when the first valve closes. The first valve is operable only when the nipple is in the socket, and the nipple is removable from the socket only when the first valve is in its closed position.

Abstract: A valve installed in the flow line of a flammable or other hazardous flowable material which normally open but will be automatically closed to interrupt the flow of flammable or hazardous material to a discharge point in the event of a hazardous condition occurring. The valve is held in an open position by a fusible link which retains a pivotal latch in engagement with a spring biased valve to retain the valve in open position. The fusible link will melt when subjected to predetermined conditions such as a high temperature condition which occurs in the event of a fire thereby releasing the latch and valve for movement to a closed position for stopping flow of flammable material in order to control the fire or other hazardous condition.

Abstract: An improved heat sensitive cut-off for blocking the flow through a gas conduit or the like of the type comprising first and second cut-off members disposed in the conduit which co-operate to block flow through the conduit when they are brought together. The first cut-off member has a socket therein. A spring biases the cut-off members together, and a spacer between the cut-off members for separates them to permit flow through the conduit. The spacer has a portion penetrating partway into the socket in the first cut-off member. A plug of a relatively low melting point material is located in the bottom of the socket for temporarily preventing the spacer from penetrating further into the socket. The socket and the spacer are configured so that when the plug melts the spacer can penetrate further into the socket sufficiently that the spring can move the cut-off members together to block the flow through the conduit.

Abstract: A fire damper or the like having butterfly-type gas flow control blades includes a heat responsive blade release assembly that incorporates a standard fusible link accessible from externally of the assembly. The fusible link holds together pivoted side plates of a housing from which extends a pair of arms normally holding the blades in their open positions. When the link melts, the side plates move apart, allowing the arms to open and release the blades. The assembly is also adjustable to vary the extent to which the blades open.

Abstract: An improved coupling device (e.g., 134) has a first section (e.g., 135), a second section (e.g., 136), and a sleeve member (e.g., 138) mounted on one of the coupling sections and arranged to selectively engage the other coupling section. The sleeve member is provided with a weakened portion (e.g., 156). The weakened portion is formed of a suitable material and is so configured and arranged as to permit the two coupling sections to be physically separated from one another through thermally-induced flexural deformation of the weakened portion, without rotation of the sleeve member relative to either section, when the temperature of the weakened portion is greater than about 200.degree. F. but less than about 300.degree. F., and preferably about 266.degree. F.

Abstract: A fire control valve and more particularly a valve installed in the flow line of a flammable or other hazardous flowable material which is normally open but will be automatically closed to interrupt the flow of flammable or hazardous material to a discharge point in the event of a hazardous condition occurring. The valve is held in an open position by a fusible link which retains a spring biased pin in engagement with a spring biased valve stem to retain the valve in open position. The fusible link will melt when subjected to predetermined conditions such as a high temperature condition which occurs in the event of a fire thereby releasing the pin and valve for movement to a closed position for stopping flow of flammable material in order to control the fire or other hazardous condition.

Abstract: A pipe coupling assembly (10, 46, 64) and method of manufacturing the same involves the use of a pipe coupling (12, 50, 66) with an intumescent collar (14, 68) and a metallic band (16, 56, 70) wrapped thereabout at one end thereof. The metallic band has overlapping ends (36, 38) which are held together by elongated fasteners (18, 60) passing through overlapping portions and into the intumescent wrap. The pipe coupling assembly including a tubularly-shaped main body, an intumescent collar, and a metallic band are assembled as a unit in a factory to be later placed in a concrete form to have concrete poured thereabout. A heat receiving edge of the metallic band receives heat from a fire in a space below a barrier in which the pipe coupling assembly is embedded and conducts it to the outer periphery of the intumescent collar.

Abstract: A fire isolation device having a valve designed to close after a given temperature has been reached by a fusible nose member in the form of a sleeve of fusible material. The device has a passageway therethrough and a self-closing valve member having a poppet and a seat disposed in the passageway with the poppet being biased toward the seat to a valve closed position. At least one aperture through the nose member provides for continuous fluid flow through the device around the poppet and the seat. The nose member is positioned to hold the valve in an open position against the bias on the poppet. The seat has a flow path on its outer end dimensioned to fit the nose member and a flow path towards its inner end larger in diameter than the nose member in an area occupied by the aperture to permit flow therethrough when the nose member holds the valve in an open position. The nose member is made of a material designed to melt in the neighborhood of 700.degree. F. when the fire isolation device is exposed to 2000.

Abstract: A damper for an air handling system in which the blade or blades are normally positioned to permit air to flow through the damper by a pneumatic cylinder which, when pneumatically actuated, overcomes the force of a spring within the pneumatic cylinder which would otherwise position the blade or blades to close the damper to air flow. The pneumatic cylinder normally receives air through a primary outlet of a three-way valve, the three-way valve also having a vent outlet and a valve member which is movable to permit pneumatic flow either from a source of pneumatic fluid through the primary outlet or from the pneumatic cylinder back through the three-way valve for venting through the vent outlet.

Abstract: A fire damper kit is set forth wherein a fire damper box is formed with a first framing angle iron fixedly secured thereto with a second angle iron slidable thereon to secure said damper and sandwich a fire wall between said opposed angle iron collars. A fusable link positions a fire damper door in a first position to enable heat flow through associated duct work wherein a chimney fire will effect a release of said door to prevent spread of a fire through the duct work.

Abstract: A fire-stop pipe coupling adaptor (10) comprises a pipe coupling (12) having an intumescent fire stop collar (14) in a metallic band (15) wrapped to form a cylinder (16) thereabout, with the metallic band having outwardly-directed radial tabs (18) at a first cylinder end (19) for attaching the metallic band to a partition (40). The pipe coupling of the adaptor has a male coupling member (46) at a first end thereof for extending into a female end (56) of a cast-in coupling (54) to be attached thereto, thereby allowing an end of the cast-in coupling to be positioned immediately adjacent to the intumescent fire stop collar and the metallic band tabs.

Abstract: An under-floor fire-stop coupling and method of construction involves a pipe coupling assembly (10) in which an elongated tubularly-shaped main body (14) has a rigidly coupled outwardly directed mainbody flange (36) to which a fire-stop metallic band (22) having intumescent material (24) therein is mounted. The metallic band includes tabs (34) at the end adjacent to the main-body flange. The main body defines an anchor indentation (46) in an outer surface above the main-body flange. The pipe coupling assembly is mounted to a floor (40) by preparing a hole (66) through the floor slightly larger than the main body, extending the main body through the hole from below the floor until the main-body flange contacts a bottom surface of the floor, and extending fasteners through the metallic band tab and the mainbody flange into the bottom of the floor.

Abstract: The improved shaft locking apparatus includes a body with a bore therethrough and includes balls mounted in radial ports in said body so that in one position the balls partially extend into the bore and in restricting the bore lock a shaft associated with the apparatus from axial movement. A heat sensitive material is used as a part of the balls supporting means and when it is subjected to excessive heat, heat above its design limitations, its support of the balls relaxes and allows their retraction from the bore to thereby allow axial movement of the shaft.

Abstract: A coupling includes a socket assembly having a locking or retaining assembly which holds a plug in the socket assembly. When the socket assembly is exposed to excessive heat, an element of the retaining assembly starts to fuse and loses its rigidity. The heat fusible element of the retaining assembly is then deformed to release the plug for movement from the socket assembly. In one embodiment of the invention, the heat fusible element of the retaining assembly is spherical locking or retaining balls which engage the plug to hold it in the socket assembly. In another embodiment of the invention, the heat fusible element of the retaining assembly is cylindrical locking or retaining pins which engage the plug to hold it in the socket assembly. In still another embodiment of the invention, the heat fusible element of the retaining assembly is a cylindrical locking sleeve which engages the retaining elements to hold them in engagement with the plug.

Abstract: A valve actuator (A, B) for automatic actuation of a rotary valve mechanism (V, V') in response to a specific exigency, such as fire. The actuator includes a housing (13) affixed in relation to the valve, having a spiral torsion spring (11, 11'). A spring coupling (20) is connected to the spring for being rotatably driven for actuation thereby of the valve mechanism (41, 61) when released. An arm (6) having a camming surface (32') operatively prevents rotation of the coupling until released. A releasable link (L) secures the arm against releasing movement. The coupling is operatively connected to a shaft (40) of the valve mechanism and mating elements (26, 27) carried by the coupling and the housing respectively lockingly interengage the coupling and housing upon actuation such that the valve mechanism is precluded from rotating in a direction contrary to the actuation direction upon actuation.

Abstract: A flow controlling valve is provided for disposition within a pipeline or the like which may be subject to excessive vibrations and/or temperature and the valve includes a valve member shiftable between open and closed positions, yieldingly biased to the closed position and retained in an open position through the utilization of frangible retaining means having a first portion connected to the valve member and a second portion anchored relative to the body of the valve through the utilization of a fusible link.

Abstract: An excess pressure and/or excess flow/temperature shutoff valve comprising a valve housing having an axial bore therethrough with inlet and outlet ends, a portion of the bore being enlarged to form a valve chamber, and a spool movable in the valve chamber and having a sealing fit with the walls of the chamber. In the event of an upstream pressure increase of predetermined magnitude, the spool is adapted to move from an open position in which it permits flow of fluid through the bore to a position wherein additional spool area is exposed to the upstream fluid pressure, whereupon the spool is adapted to move further downstream to a shut off position for blocking the flow of fluid through the bore. The valve may be optionally equipped to shut off the flow of fluid in the event of a downstream pressure decrease as a result of excess leakage and/or an increase in fluid temperature in excess of a predetermined value.

Abstract: An improved firestop fitting with a flammable main conduit (11) and extension conduit (12) supporting a non-flammable sleeve (14) and plug (16). The plug lodges into the sleeve when a harness (17) is melted by heat from a fire below the floor (100 or 101) in which the fitting is mounted which passes into the conduits. The fitting is relatively light and inexpensive.

Abstract: An adapter bracket that can be attached to the exterior of a conventional gate valve and valve actuator converting the valve to a fire safety valve. The bracket can be clamped to the exterior of the valve/actuator housing without modification to the existing structure. The bracket includes an adapter plate with an externally threaded cylindrical extension. A hole through the adapter plate is coaxial with the aperture through the cylindrical extension to non-engagingly permit the valve actuator rod to pass therethrough. The threaded extension receives a standard lock-open cap to hold the valve in the open position to avoid severing of the cable in wireline operations due to a power outage, for example. The cap includes a portion made of fusible material which, in the event of fire, will melt permitting the valve to close under operation of a biasing spring.

Abstract: A remotely controllable fluid pressure actuated mechanism for controlling the actuation of a sliding gate valve or the like, for use with tank trucks, pipelines, storage tanks or the like, for helping to eliminate the possibility of hazardous spills.

Abstract: A firestop fitting (10, 30) for mounting on a water closet carrier (200, 300) is described. The fitting includes a releasable plug (13) and is used for preventing the spread of fire through plastic pipe between floors of a building.

Abstract: A heat sensitive valve including a body having an inlet, an outlet, a valve chamber and a valve seat surrounding the opening between the inlet and the outlet, a bonnet connected to the body with a bore therethrough in communication with the valve chamber, a valve member positioned in said valve chamber and coacting with said valve seat to open and close flow through said valve, a stem connected to said valve member extending through the bore of said bonnet, a pressure responsive actuator connected to said stem with means of supplying and venting pressure fluid to an from said actuator, a housing secured to the bonnet, a linkage supported by said housing in an extended position, having means for engaging the outer end of the stem, heat sensitive means for retaining the linkage in its extended position supporting the stem and means biasing the linkage away from its extended position when said heat sensitive means releases the linkage to thereby remove support retaining said valve member in its innermost positio

Abstract: An air damper having a housing, a strut mounted across the housing, a pair of damper panels hinged on the strut, and swingable between open and closed positions, an adjustable control above the strut, and, linkage on the upper side of each panel extending to the control to cause the panels to swing from one position to the other.

Abstract: The control/fire damper (10) comprises a tubular shell (11) constituting a flow duct (12), a shaft (13) disposed within the flow duct (12) and carried by the shell (11), and a closing plate (14) mounted on the shaft (13), and which in the case of fire damper use continuously tends to close under the action of a spring (17). The control/fire damper (10) is provided with a clamping counterpart (15) attached to the closing plate (14) and with a clamping device (16) passing through the shell (11), which fixes the counterpart (15) steplessly in the position which is desired in each instance. The clamping device (16) consists of a clamping screw and, in fire damper use, of a member attached by fuse material to the end of the clamping screw.

Abstract: An auto-fill flow valve for use in providing valving action in a conduit, the valve having a releasable locking mechanism which prevents the valving element from moving to seat against the valve seat until the locking mechanism is released. Also provided is a valve guide for receiving the releasable locking mechanism and holding it against the valving element.

Abstract: Disclosed is a heat sensitive jack for overriding a valve including a valve body and a gate valve member connected to a valve stem which is operated by a linear actuator having an actuator body and an actuator stem connected to the valve stem extending outwardly of the actuator body, wherein the actuator stem is movable between an open and a closed position, and wherein no hazardous projectiles are formed when the stem moves to the closed position. The jack includes a cap connectable to the body and a nut axially movably disposed in the cap for movement between a first position and a second position, wherein the distance between the first and second positions is at least as great as the distance between the open and closed positions of the valve. A fusible element is provided to normally maintain the nut in the first position, but which upon being exposed to excessive temperature will allow the nut to move to the second position within the cap.

Abstract: A stack fitting (10) and coupling (102) combination adapted to be mounted through a floor (104) in a building to prevent the spread of fire through pipe (100, 103) from below the floor is described. The fitting includes a thermally releasable plug (13) mounted in an extension conduit (12) from a main conduit (11) of the fitting which is activated by a fire to allow the plug to move into the main conduit. The fitting is particularly adapted for multi floor buildings where plastic pipe is to be used.

Abstract: A plurality of valve structures are incorporated in a drill pipe string for drilling a well into the earth utilizing air as the drilling fluid. A first valve is located in the drill pipe string just above the drilling bit, and an additional valve or valves are located in upwardly spaced relation within the drill collar string. Each of the valves has a valve member held in a position allowing the flow of air through the valve by a fusible support, and when the support melts, the valve member will shift to a position closing the valve. The valve just above the bit is combined with a float valve to prevent the upward flow of fluid into the drill string, while the valve or valves spaced upwardly in the drill collar string are full opening valves which allow the running of instruments through the drill string to selected locations above the bit. The additional upwardly spaced valve or valves include a flap held in a position to one side of the bore through the valve body by a fusible retainer.

Abstract: A transversely circular fire damper having a butterfly type blade operated by a jack shaft spaced longitudinally of the housing from the blade axle. Linkage including an "over center" stop rotates the blade in one direction by operation of a motor coupled with the shaft. A clutch in the form of a pair of relatively telescoped members secured together with entectic solder is connected with the jack shaft and the motor so that the shaft is released from the motor when the ambient temperature reaches a point high enough to melt the solder. The jack shaft is spring biased in a direction to close the damper blade under such condition.

Abstract: A damper operator for use with a damper having a frame and a damper blade pivotally associated with the frame, which damper operator comprises a drive rod; a pair of lever arms which are pivotally associated with each and which extend between the drive rod and a pivoting mechanism associated with the blade of the damper; and a latching mechanism which extends between portions of each of the lever arms, and which permits selective engagement and disengagement between those portions of the lever arms, and accordingly, selective respective rotation of the lever arms, so that the blade of the damper can be urged toward a predetermined orientation; and biasing means to urge the damper closed when the arms are disengaged; and means to prevent the blade from opening when the arms are disengaged and the blade has been biased shut.

Abstract: A fire responsive stem retention apparatus for a non-rising stem valve including an outer hollow sleeve secured to the top of the valve bonnet around the valve stem. An inner cap is received in the outer hollow sleeve and closely fitted therewithin, and houses upper and lower stem bearings therein. The inner cap has a shoulder which provides an upper support for the upper stem bearing. Under normal environmental conditions, the inner cap is sweated to the outer sleeve with a thin layer of fusible material. The upper bearing and stem are prevented from moving upward by the shoulder on the inner cap, and an annular shoulder on the stem is prevented from engaging a backseat in the bonnet. Under fire conditions, the thin layer of fusible material melts rapidly, freeing the inner cap from the outer sleeve and permitting the stem to rise until the annular shoulder on the stem engages the backseat in the bonnet.

Abstract: There is described a fire-break for passing at least one hollow element such as pipe, sleeve, tube, through a building wall, notably a partition or ceiling, which comprises a flange from substantially incombustible material which is mounted around said element.

Abstract: An actuator for a rotary valve includes a fail-safe mechanism for automatically opening or closing the valve upon the occurrence of a predetermined condition. The actuator also includes a mechanism for permitting the manual operation of the valve from the open to closed position, and vice versa, and to a continuum of positions between the open and closed positions even when the fail-safe mechanism is activated. A biased clutch activates the fail-safe mechanism and also couples a worm-gear drive for effecting the manual operation of the valve.

Abstract: A spring-powered actuator especially for operating devices such as fire and/or smoke dampers, doors, hatches, vents, traps, valves and other devices having components which are movable between at least two positions. The spring-powered actuator of the invention comprises a longitudinally-displaceable re-wind screw which is rotatable to recharge the spring of the actuator, and a tilting element on the screw which is mounted for tilting movement with respect to the screw axis to allow longitudinal movement of the re-wind screw so as to permit rapid and reliable release of energy stored in the spring. When used in a combination fire and smoke damper, it thus opens or closes the blades of the latter.

Abstract: This device is for balancing air flow and the dispersion of air around duct throats, and is particularly adapted for already manufactured filter modules and ceiling air conditioning diffusers, where concern for spreading fire through the openings is involved. Primarily, it consists of a core assembly for the filter module hood. The assembly includes a mounted bolt and a pair of perforate discs, which will serve as a flame barrier automatically, when fire is present, and the assembly further includes a low melting point solder for its automatic operation.

Abstract: A diaphragm type gas pressure reducing regulator and adapter in combination in which the adapter serves to isolate the diaphragm from the valve seat in the regulator in response to a spontaneous ignition. The adapter comprises a plunger which intercouples the valve and the diaphragm assembly during normal operation of the regulator and isolates the diaphragm assembly from the valve in response to a spontaneous ignition within the regulator body upstream of the diaphragm assembly.

Abstract: An exhaust air valve for placement in a ventilation conduit through which air is exhausted from a space to be ventilated. The valve has a casing with a concave seat surface facing upstream of the flow through the conduit and having a central valve orifice. A convex valve element cooperates with the seat surface and when the valve is closed engages the seat surface along a line of contact surrounding the seat. The curvature of the respective surfaces is the same, at least along the line of contact to ensure a tight closure of the orifice by the valve body. When opening, the valve body slides along the curved surface and the upstream surface of the valve body exposed to the flow is also convex to guide the flow toward the center of the orifice. Several embodiments are illustrated including valves with cords for remotely controlling the valve and heat-sensitive tripping mechanisms which automatically close the valve in the event of a rise in temperature above a preset level.

Abstract: A stem-operated fire-resistant gate valve including an improved metal-to-metal stem backseat a eutectic ring assembly for facilitating automatic stem backseating at pre-selected temperatures, spring enhancement of the backseating procedure, and a lost motion connection between the valve stem and the valve closure element.

Abstract: A valve operator having a piston or diaphragm and connected polygonal piston rod which supplies reciprocable motion to a key or follower which acts within a spiraled slot formed in a coupling member attached to a valve gate to rotate the valve gate to a desired angular position. One embodiment includes means to bias the piston and the valve gate in a desired angular position from closed to open or therebetween.

Abstract: A butterfly damper with a plurality of blades which can be locked in the open position, and which, when released, rotate about a hinge to the closed position. A pawl member, attached to one blade, extends away from the blade and through an opening in a second blade when the blades are in the open position. A mounting member attached to the second blade restrains the pawl member thereby holding the blades in the open position. A bimetallic link attached to the mounting member causes the pawl member to be released when the temperature of the air passing through the duct increases beyond a preselected level. A closure spring attached to the blades acts on the blades tending to force them apart against the action of the mounting member and the pawl member when the blades are restrained in the open position. The damper blades can be insulated to prevent the heat from a fire on one side of the damper from being conducted by the damper to the other side when the blades are in the closed position.