一、前言作为超压保护装置的蒸汽用弹簧全启式安全阀,有关标准对其超过压力和启闭压差提出了严格的要求。以往国内生产的蒸汽用弹簧全启式安全阀一般采用单调节圈结构。这种结构的安全阀是 I. Introduction As the overpressure protection device steam spring all-in-one safety valve, the relevant standards over its pressure and opening and closing differential pressure put forward strict requirements. In the past, the domestic production of steam spring-type safety valve is generally used single-adjustment ring structure. This structure of the safety valve is