| 摘要 |
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. Since the both springs are effectively mounted through the valve body, the exhaust port can be automatically opened and closed with the spring of shape memory alloy and the bias spring instead of the conventional bellows.
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