Patent GB-543480-A (GB)
Title: Improvements in or relating to steam heating systems
IPC: F24D1/00
Filed: 1941-05-19
Abstract: 543,480. Valves. VAPOR CAR HEATING CO., Inc. May 19, 1941, No. 6441. Convention date, May 17, 1940. [Class 135] [Also in Group XIII ] A number of radiators are supplied in parallel from a source or relatively high pressure steam through a regulating valve to a common supply pipe which supplies each radiator independently. The supply pipe is kept filled with steam at a predetermined low pressure by means responsive to the pressure in it. Means are provided to allow a small flow of steam through the pipe system to prevent freezing. Steam passes from a high pressure main A through regulator B to the supply pipe C and thence through thermostatic electrically controlled valves G to radiators F. A thermostatic retarder D at the end of pipe C co-operates with a pressure-limit valve E to control the regulator B to keep the pipe C filled with low pressure steam. Each radiator discharges through a retarder J to a common return K and thence to the drip pipe L. A reducing valve 5 reduces the steam supply pressure from about 250 p.s.i. to about 20 p.s.i. In the regulator B, Fig. 7, steam passes from inlet 9 through strainer 10, past valve 15 to outlet 13 and pipe C, and a similar opposite outlet to pipe 14 and valve E. A thermostatic control device 20 is housed in a heat radiating casing 22, and actuates the valve stem 30 through a pivoted lever 27. Exhaust steam from the radiators does not pass into the chamber 22 but to the retarders J. Steam from the chamber 12 and pipe C passes to the inlet 35 of pressure-limit valve E, Fig. 8, the outlet 41 of which is connected to the chamber 22, Fig. 7. A valve seat 43 comprises a cage structure which supports a guide 51 and is threaded into the web 37. A strainer 46 closes the lower end of valve port 45. A spring 52 is adapted to allow the valve to open at a predetermined pressure in the inlet 35, chamber 12 and pipe C, say 5 p.s.i., and allow steam to pass to the chamber 22, Fig. 7, whereby the bellows partly closes valve 15, and maintains it in such a position that the desired pressure is maintained in pipe C, notwithstanding a variation in the number of radiators in use. Steam from the pipe C enters the radiator valve G, Fig. 3, at 73, passes through a central pipe 59 to the remote end of the radiator F and thence to return pipe 68. The valve stem 79 is guided in a cage member 75 which also forms the valve seating, and carries a collar 81 forming part of the manual control mechanism. A solenoid assembly 84 is mounted on the valve casing and is adapted to close the valve against spring 83 when energized by thermostat M, Fig. 1. The circuit is shown in Fig. 6. The mercury column 92 closes the circuit at a temperature which is dependent on the room temperature and also the amount of heat applied by heater coil 95 which can be regulated by resistance 99 to vary the temperature control in the room. Completion of the circuit short-circuits the relay 102, closes switch 108 and energizes solenoid 88 to close valve 77. Manual actuation of valve 77 is effected by rotating spindle 114 carrying a disc 113 with arcuate recess 115 and also recesses 119, 120, 121, any one of which can be engaged by spring-pressed catch 116 to hold the valve in open or closed position, or in position shown, to leave it subject to solenoid control. To prevent entry of steam to the pipe 73 and undesirable heating of the room when the valve G is closed, the fitting 129 is formed as a water seal and the pipe 73 becomes partly filled with water. A small vent is provided to allow this to discharge. The valve seat of the thermostatic retarder D is notched to allow a small flow of steam when the valve is closed, to prevent freezing of the pipe system.