PURPOSE: To prevent air from being absorbed through joints or the like of the piping keeping the internal pressure of the piping above the negative level with a circulating pump and a bypath of the pump having a check valve provided in the return piping to the hot water destinations from boilers or the like.
CONSTITUTION: A circulating pump G is interposed in the course of the return piping 3b to cock faucets 2 ... from a boiler B for forced circulation of hot water to check excessive drop in the temperature of the hot water in the piping when the hot water is not used. A pump G is provided with a bypath 4 having a check valve 5 while a check valve 6 is interposed in the course of the piping between the expansion tank 1 and the return piping 3b. With such an arrangement, it is possible to invariably maintain the internal pressure of the piping thereby preventing air from being blown through joints of pipings, rotary sliding parts of the pump G and the like. The pump G poses no resistance during the use of the hot water with an aid of the bypath 4 without being replaced with a large capacity type. Thus, sufficient amount of feeding water is made available.
TOKUTANI KATSUHISA
UEDA YUTAKA
| JPS5219240U | 1977-02-10 |