Abstract: A vehicle heating system comprising: a coolant circuit that circulates coolant between an engine and a heater core; heating device that heats coolant, which is interposed in the coolant circuit; a pump for coolant circulation, which is interposed in the coolant circuit; and a switching valve that switches the coolant flowing through the coolant circuit between a heater-core-side circuit that circuits the coolant among the heater core, the pump and the heating device and an engine-side circuit that circulates the coolant into the engine, wherein the switching valve has a thermo valve that switches channels so that the coolant coming from the engine-side circuit enters either one of the heater-core-side circuit and the engine-side circuit according to temperature of the coolant, and a bypass that delivers the coolant, which comes from the heater-core-side circuit, to the heater-core-side circuit.
Abstract: A valve and actuator assembly includes a valve to control a flow of liquid into a coil, and an actuator to control the valve. The assembly includes a first temperature sensor to sense the temperature of liquid flowing through the valve, a second temperature sensor to sense the temperature of air surrounding the coil, and a flow meter to measure a flow rate of liquid through the valve. The actuator includes a module that receives data from the first and second temperature sensors and from the flow meter, and determines, based on data received from the flow meter and temperature sensors, a likelihood that the liquid in the coil will freeze. The actuator operates the valve to allow a minimum flow of the liquid through the valve and coil during a potential freeze condition. The minimum flow is sufficient to prevent the liquid in the coil from freezing.
Abstract: A modular shell system of a hard insulation material fabricated in a geometric shape that encapsulates a pipe in insulation is provided. In an attic installation for example, the entire insulation component is inserted over a pipe and into the space between the building structural wood framing members resting on the interior sheathing below. By placing a series of these interlocking insulating modules along a pipe that is run perpendicular to the building construction members, the piping is encapsulated in a continuous insulating system along its entire length. This design facilitates natural heat flow into the pipe with an open pipe slot cavity in the insulating module that allows natural convection heat to pass up through the elongated piping slot, allowing it to come into contact with this piping.
Abstract: Systems and methods for using a dual-path fluid routing system that uses a flow restriction device to enhance temperature and pressure control of fluid are provided. Systems and methods for using a setpoint pressure control system to accurately control the setpoint pressure of a regulator are also provided.
Abstract: The present invention relates to a hot water supplying system that includes a preheating-circulating system, which heats water to maximally reduce the time to attain a temperature set by a user, and is designed to use a portion of preheating energy for heating, preventing pipelines from being frozen to burst in winter by preheating-circulating.
Abstract: Disclosed in this invention is a method and device for de-icing, snow melting and thawing frozen ground. The invention is based on warm moisture-laden air that can be blown over the surface to be iced or thawed or it can be introduced into an enclosed area where de-icing, ground thawing or snow melting is desired. The device consists of three components: a hot water or a steam boiler with an associated pump; a plenum for heating and humidifying air; and a delivery unit or head that brings the moisture-laden air into contact with the surface to be de-iced or thawed. In one embodiment the boiler is replaced by a direct fired burner. The delivery unit may be an air blanket with multiple perforations attached to an air duct or an inverted saucer-like delivery head likewise attached to an air duct, coming from the plenum or it can be simply an enclosed space in which is located the object to be de-iced or thawed and into which the hot moisture-laden air is conducted.
June 15, 2004
Date of Patent:
February 26, 2008
Chinook Mobile Heating and Deicing Corporation
Abstract: A method of controlling operation of a liquid-fuel combustion appliance. The method is characterized by including an “antiseize operating mode” in which an electric motor and a fuel pump, powered by the electric motor, are started periodically to prevent oxidation and/or polymerization of the liquid fuel in the fuel pump when the fuel pump is idle. More specifically, the fuel pump is a gear pump.
Abstract: A closed piping comprised of ground water pipe of a water supply system buried in the stratum and a closed water pipe provided on the ground to execute thermal conduction for equilibrating temperature from the thermal energy in the deeper stratum to a subject matter on the ground by the current running in the closed water pipes.
Abstract: A snow melting system including a controller, a first heater supplying heat under the control of the controller, the first heater supplying heat at a power density, a moisture detection apparatus located apart from the first heater, the moisture detection apparatus communicatively coupled to the controller and a second heater located proximate to the moisture detection apparatus, the controller directing power to the second heater at an other power density, the other power density substantially the same as the power density.
Abstract: An ice and snow melting heater control assembly including at least one sensor, at least one heater element and a controller communicatively coupled with the at least one sensor and the at least one heater element, the controller directing status information about at least one sensor to the at least one heater element.
Abstract: A combination capable of providing all of the functions of a ground heater and a pressure washer in a more economical, convenient and effective manner by employing and engine, as pump, a generator, a burner, a boiler, a water tank, a float tank, a ground heater hose and reel, and a pressure washer hose and reel all mounted on a skid or trailer.
Abstract: In installations with water circuits such as domestic hot water or hydronic heating circuits a circulator pump is connected with a temperature sensor which energizes the pump as soon as the temperature of the water in the system falls below a predetermined temperature close to freezing.
January 24, 2002
Date of Patent:
September 23, 2003
Karsten Andreas Laing, Johannes Nikolaus Laing
Abstract: Apparatus and method for heating and preventing freeze-off of wellhead equipment utilize radiant heat from a flameless heater to heat fluid in a heat exchanger, such as a tank or finned radiator. A pump is used to circulate the heated fluid through a conduit loop deployed in thermal contact with the equipment to be heated, such that the heat from the fluid is transferred to the equipment, maintaining it at sufficient temperature to prevent freeze-off. The apparatus and method may also be used for other purposes, such as for circulating heated fluid through a liquid-cooled engine to facilitate cold weather starting.
Abstract: The aim of the invention is to prevent outer taps from being damaged by the effects of frost. To this end, the invention provides a heating device for heating a tap (1) with an electrothermal converter (2) means. Said heating device is mounted in or on the tap. The invention also relates to a valve device in which a heating means can be plugged into a corresponding socket (11), thereby effectively preventing the tap from freezing.
Abstract: A plumbing system which, when ambient outdoor temperatures drop below freezing, circulates water to prevent it from freezing, utilizing a check valve to prevent water from flowing back into the water main and further utilizing a relief valve which can open to the atmosphere and relieve pressure in the system if necessary. The system can have two separate circulation pumps, one for hot water and one for cold water.
Abstract: A space heater for heating air from within a room with a heat exchanger connected to a burner and discharging heated air into the room has a room temperature sensor for detecting a room temperature and a controller for controlling the burner with a freeze prevention temperature set to prevent indoor facilities from being frozen. When the detected room temperature drops to or below the freeze prevention temperature, the controller operates the burner and controls the burner with a lower limit for an amount of heat in the burner with which no moisture condensation occurs in the heat exchanger.
Abstract: An installation for melting of snow or ice, e.g. at roof downpipes on flat roofs, in gutters and the like, comprising a heating means (11), a temperature sensor means (4,6) and a control unit (1) for connecting and disconnecting the heating means (11) in dependence on sensed temperature. The temperature sensor means comprises a first temperature sensor (4) for sensing the surface temperature at the place of snow or ice melting, and a second temperature sensor (6) for sensing the air temperature at the topical place.
Abstract: According to the present invention, water regulation assemblies disposed in the water supply path of conventional fixtures are modified to include a pressure relief assembly which permits release of water under elevated pressures. A normal shut-off seal included in the water regulation assembly is modified to release water in response to elevated pressure even when the seal is placed in a shut-off position. This permits relief of elevated pressure in water supply lines which might otherwise produce a burst event within the water supply lines. Preferred modified shut-off seals include a washer having soft portions which deform to permit pressure relief by release of water past the shut-off seal in response to elevated pressure and a gasket including a region of reduced thickness which deforms in response to elevated water supply pressure thereby releasing water into the socket and relieving water supply line pressure.
June 14, 1996
Date of Patent:
March 24, 1998
The Board of Trustees of the University of Illinois
Abstract: Apparatus for automatically opening an orifice to allow flow when ambient temperature drops below a predetermined level, such as the freezing point of water. The apparatus is for connection to a liquid line that carries liquid at a selected pressure for producing a selected low flow rate of liquid from the liquid line when the ambient temperature drops below a selected temperature. The apparatus comprises an orifice in the end of the liquid line of selected small diameter, a closed chamber means having an expansible portion filled with a selected condensible gas, for which the vapor pressure varies with temperature in a known manner. The apparatus further comprises a valve assembly selectively positioned adjacent the orifice and at a specific distance from the expansible portion of the closed chamber. The closure means is selectively positioned by means of spacers positioned adjacent the valve assembly.
Abstract: A snow and ice melt control system is provided to melt snow and ice from a slab, a temperature sensor means are provided at the input and output from the slab, and a differential temperature is generated reflecting the condition of the slab in respect to the ambient temperature. A controller is provided to adjust the amount of heat and heated fluid flowing to the slab to actively respond to environmental conditions to more efficiently melt snow and ice on the slab.
Abstract: For use with a watering trough fill control valve having float structure located to rise as water is filled into the trough via the valve, and to effect closing of the valve when the trough is filled to predetermined extent, the float structure located to fall as water level lowers in the trough, the float structure controlling a water inlet subject to freezing in closed position in winter, comprising an apparatus operatively connectible with the float structure for biasing the structure, so that it cannot completely close off ingress of water at the inlet as ambient temperature drops below water freezing level; the apparatus including a bimetallic control element.
June 20, 1994
Date of Patent:
September 10, 1996
Herbert W. Hoeptner, III
Herbert W. Hoeptner, III, Herbert W. Hoeptner, Jr., Rahl E. Hoeptner
Abstract: A recreational vehicle winterizing device adapted for use in association with a recreational vehicle including a water supply system with a plurality of interconnected rigid pipes, the apparatus comprising: a canister formed in a hollow cylindrical configuration with an upper surface including an aperture, a cylindrical neck with screw threads being positioned around the aperture, antifreeze fluid being positioned within the canister, a tube being positioned through the upper surface and extending within the canister, the tube including a valve to enable the user to regulate the flow of antifreeze therethrough; and a pump assembly including a handle, a cylindrical member and a collar with screw threads, the collar threadedly coupling the cylindrical member through the neck of the canister, the handle having an upper extent including a gripping ring and a lower extent including a rod slidably positioned through the cylindrical member, a user gripping the handle and forcing the rod upward and downward thereby c
Abstract: A fluidizing apparatus, such as a winterizing apparatus, and related method for preventing freezing of water in the water pipes of a dwelling. The apparatus includes a pump, an inlet line, an outlet line, a pressure switch, and an air compressor tank. The outlet line is connected to a faucet of the water pipes of the dwelling and the inlet line is positioned in a container of fluid, such as antifreeze. When a second faucet is opened, the pump is activated, and the pump will then cause antifreeze to flow from the container, through the inlet line, the pump, and the outlet line, and then into the faucet and through the water pipes of the dwelling. An associated air compressor tank is in fluid communication with the pressure switch and exit line, and cooperates with the pressure switch to maintain consistent pumping of the antifreeze. After antifreeze is in the pipes, a shut-off valve in the exit line is closed and/or the at least one valved water outlet is closed, which causes the pump to deactivate.
Abstract: A method to prevent freezing of water in a conduit that carries the water out of a building. The method uses a device that alternately accumulates the water in a container and then dumps it. The water is then carried to the outside of the building through a conduit. The water, being released in batches, does not have time to freeze in the conduit.
Abstract: The present invention provides a water piping system wherein when a predetermined time elapses after the flow of the water in a hose has stopped, the water is drawn out of the hose, thereby preventing proliferation of various bacteria in the water standing stagnant in the hose and when the temperature of the water drops, the water is completely drawn out of the hose, thereby preventing a water pipe from rupturing or cracking in the wintertime. The water pipe including a reducing valve which is at a position higher than a waterstop valve is connected with a hose through a first electromagnetic valve. The required number of second electromagnetic valves are located intermediate on the hose. When a predetermined time elapses after the flow of the water through the hose has stopped, the first valve is temporalily closed while the second valves are opened.
Abstract: A method and an apparatus to aid in the prevention of pipe freezing. This method utilizes fluid in motion to help pipes resist freezing. When initiated by the control circuit, fluid flows through the pipes to prevent freezing. The control system utilizes either a fixed duty cycle, a variable duty cycle, a duty cycle which can be selected or a temperature sensor. Other apparatus of this sort use the heat produced by electrical current to heat a pipe to prevent freezing. The method and apparatus described here utilizes fluid in motion to accomplish a similar task. This method is particularly suited for hot water circulating types of systems.
Abstract: A water freeze prevention device is provided and includes a mechanism that is installed between a water meter and incoming water pipes to drain the water pipes to prevent the water pipes from freezing during severe cold weather conditions.
Abstract: The present invention relates to a method and device for cold transfer. According to the invention, in an intermediate loop (2) a cold-bearing fluid being in diphasic form, that is, a homogeneous mixture of water and ice, for example. This fluid is heat exchanged, on the one hand with a primary source of cold, and on the other hand with the various secondary sources of heat represented by each enclosure (1) to be cooled. the invention is adaptable to the thermal control of a vinification process.
Abstract: A water freeze guard valve having a water-filled actuator chamber and a linkage assembly for transmitting linear expansion movement, caused by ice formation within the actuator chamber, to force a poppet disc against the seat of the valve supply port and thereby close the valve when freezing conditions occur, a latch assembly for keeping the valve open prior to freezing weather, a spring to keep the valve closed during the subsequent thaw, and a lever for manually and selectively re-opening the valve. When installed in a water supply line for a building structure that is subject to freezing and thawing conditions, the valve shuts off the supply of water to the building structure during the freeze and prevents further supply of water to the building after the thaw occurs so that the interior of the building is not damaged by flooding.
Abstract: A pressure-activated diaphragm valve which when installed in the main up-stream side of a pressurized line, responds to signals from a control unit to shut off the main supply line and at the same time, opens a drain port on the down-stream side of the valve. When used as a freeze protection system, the main water line is shut off and the drain port opened before the freeze point, thereby, eliminating water damage from frozen, broken pipes. The valve also is self-cleaning and has a magnetic plug to remove and keep metallic particles out of the control chamber and the control unit has automatic and manual modes.
August 19, 1991
Date of Patent:
May 19, 1992
Harold L. Hull, Rudolph R. Romo, Donald J. Luschar
Abstract: An anti-freezing device for use in water supply conduits, which includes a driving chamber for imparting a drive to a main valve which is moved by the volumetric expansion due to the freezing of water therein so that the main valve is separated from a valve seat thereby to discharge water in the conduit outside therethrough. The flowing movement of water in the conduit prevents it from freezing.
Abstract: This invention relates to a screw stopper including an anti-freeze device used for water pipe valve and fitted to the lower end portion of an open/close movable valve of said water pipe valve comprises: a small perforation penetrated centrally on the lower portion of the said screw stopper; a water-through recess formed on a countersink portion of the said screw stopper; a small movable member including a small valve for opening and closing an aperture of the said small perforation, and said small movable member partially defining an water-through passage; a pair of springs for holding said small movable member, at least of which is made of shape-memory alloy; an outer cylinder for holding said pair of springs screwed and fitted to the said screw stopper; and a packing for sealing up water by a valve seat.
Abstract: A heat exchanging or circulation apparatus comprising a system of conduits connected to an inlet and an outlet for circulating water or other practically incompressible liquid through the system, heat being transferred through the conduit walls, circulation through the apparatus being periodically shut-off, whereupon continued heat transfer through the conduit walls causes freezing of the liquid to ice in the conduits.
Abstract: A temperature-responsive valve comprises a pair of wax-filled thermal actuators connected in series and set to expand at different temperatures respectively at the high and low limits of a temperature range. In one version, a valve element is movable by the actuators through an orifice form one side thereof to the other, closing the orifice when in an intermediate position, and opening the orifice when one actuator expands and when the other actuator contracts. The actuators are both in contact with the fluid controlled by the valve in the first version. In a second version, one of the actuators is isolated from the controlled fluid and responsive to the ambient temperature. In a third version, the valve is a snap-action valve, in which the series actuators operate a cam which normally holds latching balls in a projecting condition in which they engage a detent to hold the valve element closed.
Abstract: An air control device, having a panel which opens and closes in response to changes in environmental conditions in a building, preferably is sized to replace a ceiling tile in a conventional drop ceiling. The air control device may be responsive, for example, to a change in temperature of the air space above a conventional drop ceiling, raising the panel when the temperature drops to near freezing, allowing air from below the drop ceiling to commingle with air above the drop ceiling. A support in rolling contact with the underside of the panel maintains the panel open, the support including a fusible fire link which fails or fractures in the event of a fire, thus allowing the panel to fall, insuring that the fire rating of the ceiling is not compromised.
Abstract: A self-actuating drip valve for attachment to a standard outdoor faucet for the prevention of freezing of such exposed faucets and water pipes leading to the faucet. A tube includes a collar at one end for securing to the end of the faucet. A stem extends within the tube so as to be adjacent the faucet. One or more ports extend between the faucet and the interior of the tube. The distal end of the stem mates with an orifice through the distal end of the tube. The tube and stem have different coefficients of expansion, one being plastic and the other being metal. In practice, the tube is attached to the faucet, which is open, and is filled with water. When the outside ambient temperature drops, the tube and stem contract at different rates and the relative movement opens the orifice in the distal end of the tube so as to permit water to drip therethrough.
Abstract: For freeze protection of a water line, a T fitting in the line is provided with a removable threaded bushing having a plug with radially projecting balls which engage J-shaped slots in the bushing to provide a bayonet joint. The plug is released when freezing conditions threaten by retraction of the balls in response to movement of a cam inside the plug by a thermal actuator also inside the plug. A check valve in the T fitting is closed automatically when the threaded bushing is removed. Modified versions include a plug having dual actuators in series, a plug combined with a flanged bushing for use in freeze protection of a compressor head, a plug combined with a valve to provide a snap-action drain valve with a more easily replaceable actuator assembly, and a plug using a water-filled glass vial as an actuator. A building protection system and a locomotive coolant system, both use freeze protection devices in accordance with the invention.
Abstract: A self-actuating drip for attachment to a standard faucet for the prevention of freezing of such exposed faucets and water pipes leading to the faucets. An elongated housing includes a collar for securing one end of the housing about the open end of the faucet. A tube extends from the collar and mates with a closure at its distal end. A stem extends within the tube from the closure and terminates in a tip which mates with an exit port extending through said collar. A compressible seal adjacent the stem closes the exit port between the collar and the interior of the tube when the ambient temperature is above freezing. The tube and stem are of different materials, one being plastic and the other being metal. Since the plastic and metal have different coefficients of expansion, a reduction of ambient temperature below freezing releases the seal and permits water to flow from the faucet through the tube.
Abstract: A freeze prevention device for water systems includes a relief valve and an actuator having an elongated chamber which contains water and segments that sequentially sense the incremental expansion caused by ice formation therebetween. The segments are axially aligned within the chamber. The segments may be balls, truncated pyramids, and the like that have a sealing portion and an axial portion with a foot which is adapted to engage an adjusting screw or a wear compensating spring at the bottom of the chamber or the top of the adjacent segment. An actuation linkage transmits linear meovement of one or more segments to a poppet in a valve seat, thereby opening a valve port connecting water, from a water supply system or a tank, to a discharge port, whereby water may be bled from the water system to prevent freezing thereof, or steam from a steam system for admission to tracer lines.
Abstract: Dump valve assembly for a cooling system in which the coolant is water without antifreeze, the system having a compressed air-operated dump valve supplied with operating air from a special reservoir charged through a check valve with compressed air from an associated compressed air system and, under emergency conditions when the associated compressed air system is shut down, automatically operating the dump valve by discharging compressed air thereto under control of a temperature responsive solenoid-actuated valve.
Abstract: A valve activating system is provided, which is intended for association with a valve assembly including a valve housing defining a conduit therein which includes a fluid inlet opening and a fluid outlet opening, and a valve which is normally biased in a closed position in the conduit to control the flow of fluids therethrough. In order to activate the valve an opening is provided into the conduit for insertion of a valve activating element, such as a simple lever which is positioned at a location at which it can activate the valve. In the embodiment shown, the opening into the conduit has a circular cross-section and is fitted with a sealing O-ring. The lever is sized and shaped so that its insertion through the O-ring will complete a fluid tight closure of the opening so that fluid present in or flowing through the conduit cannot exit through the opening provided for the lever. Therefore the valve activating system remains dry.
Abstract: A transducer assembly having a housing provided with an inlet port which is adapted for communication with an exhaust passage of an internal combustion engine. The housing includes at least one pressure chamber to which the inlet port opens and an apparatus for detecting pressure in the chamber. The inlet passage to the chamber being subject to ice blockage when ambient temperatures fall below freezing. As such, an apparatus which extends at least partially through the inlet passage is provided to prevent complete ice blockage of the inlet passage whereby assuring proper performance of the transducer assembly.
Abstract: The invention relates to a fluid flow monitor and control system which prevents excessive fluid loss and property damage. The invention warns of impending distribution pipe freeze conditions, or ruptures from other causes, shuts off the fluid supply, and vents and drains the piping network under freeze and rupture conditions. Furthermore, the invention shuts off fluid flow if the volume of flow or the velocity exceeds desired norms. An example of its application is as a water main shut-off for residential houses and commercial buildings, it also can be used for industrial processing applications.
Abstract: A system for freeze protection of pipes is provided, comprising a cold water supply line, connected to a main water supply line at one end and to at least one cold water fixture at the other end; a hot water tank having an inlet and an outlet; a hot water tank inlet line, connected at one end to the cold water supply line, and at the other end to the hot water tank inlet; a hot water supply line, connected to the hot water tank outlet at one end and to at least one hot water fixture at the other end; at least one restrictive connection, connecting between the cold water supply line and the hot water supply line; and a circulating pump, connected in-line in a circuit comprising the cold water supply line, the hot water tank inlet line, the hot water tank, the hot water supply line and the restrictive connection.
Abstract: An automatic liquid flow control unit is adapted to be attached to an externally threaded spigot to enable liquid to trickle therethrough in order to avoid liquid freeze-up. The unit includes a rigid conduit which includes an internally threaded fastener which can be directly coupled to the threaded spigot. The conduit carries a solenoid actuated valve and a thermal switch which is electrically coupled to the valve to open the latter to a water trickling mode. The thermal switch senses the outside temperature of the conduit and thus is virtually directly responsive to the temperature of liquid within the conduit. The valve can be opened independently of the thermal switch to provide a normal water flow without removal of the unit from the spigot.
Abstract: An antiburst system for water lines. A pipe has an inlet connected to a source of water and an outlet. A flexible tube is positioned in the pipe and is supported by a coiled spring extending along the longitudinal axis of the tube. An air vent section is coupled to the interior of the flexible tube for enabling atmospheric air to enter and escape from the interior of the flexible tube.
Abstract: An automatically operated valve to prevent freezing of water lines. The valve is elongated, having threads on one end to be received in a conventional plumbing tee or the like, or in a threaded opening in a faucet. The opposite end discharges water during dripping, and has a nipple to receive a hose to divert the waste water. A temperature sensitive device is in contact with the water, and includes a tip that projects at high temperatures and retracts at near-freezing temperatures. A plunger in the elongate valve is moved to close a valve when the tip is projected, and a spring within the drip valve urges the plunger to open the valve when the tip is retractable. The temperature sensitive device is carried by the drip valve by mating threads so the position of the temperature sensitive device can be varied through the threaded engagement.
October 22, 1985
Date of Patent:
January 27, 1987
Wyman L. Barrineau, Sr., Julius P. Barrineau
Abstract: The freeze protection valve includes a molded plastic valve housing (A) including a peripheral wall (10) which defines an elongated recess (12) therein. The valve housing includes a first seating region (18) surrounding the elongated recess open end, a drain outlet (C) in fluid communication with the elongated recess, and at least one side fluid passage defining configuration (30). The side fluid passage defining configuration defines a first recess (32) having a wall portion (34) which is adapted to be cut through to provide one or more fluid passages (170) into the elongated recess. A first fitting assembly (60) includes a metal nipple (62) having a flange (64) peripherally therearound, a hold down plate (68), and a plurality of screws (70) for pressing the hold down plate and nipple flange in a fluid sealing relationship with the first or second seating region.
Abstract: A freeze preventing valve which comprises a valve cage body longitudinally provided with a cylindrical guide at the upper part thereof in a valve housing connected to a steam feed pipe, a valve element having a shaft disposed through the guide of the valve body to be able to open an exhaust port opened at the lower end of the housing and to be elevationally guided in the guide of the housing, a spring of shape memory alloy interposed between the lower surface of the valve body and the valve element for urging the valve element to close the valve element, a bias spring mounted between the upper surface of the valve body and the shaft protruding from the guide of the valve element upwardly for urging the valve element to open the valve element. Thus, the valve element of the freeze preventing valve is effectively supported and guided in the housing via the guide of the valve body.
Abstract: A freeze preventing valve which comprises a valve body longitudinally provided with an inserting hole at the upper part thereof in a hollow valve housing connected to a steam feed pipe, a valve element having a shaft disposed movably through the inserting hole of the valve body to be able to open an exhaust port at the lower end of the housing and to be vertically guided through the inserting hole of the housing. A collar is secured at an intermediate position on the shaft and a spring of shape memory alloy is interposed between the upper surface of a valve seat of the valve housing and the lower surface of the collar for urging the valve element to close the valve, by moving the valve element upwardly. A bias spring is mounted between the lower surface of the upper part of the valve body and the upper surface of the collar for urging the valve element to open the valve.