Torsion spring checks shall have reversible elastomer discs and in operation produce drip tight closure against reverse flow caused by backpressure or backsiphonage 扭力弹簧止回阀应该配置双向合成橡胶阀瓣，并且在工作时对于反压力和反虹吸所产生的回流具有防滴漏关闭性能。
The reduced pressure detector assembly shall consist of two independent torsion spring check modules , a differential pressure relief valve located between and below the two modules , two drip tight shutoff valves , and required torsion spring check modules and relief valve shall be contained within a sleeve accessible single housing constructed from 304 ( sch 40 ) stainless steel pipe with groove end connections 这种减压检测器总成应该包括两个独立扭力弹簧止回阀模块，一个位于两个模块之间的下方的差压安全阀，两个防滴漏关闭阀，并且要求扭力弹簧止回模块和安全阀应该放置在一个套筒内，要易于接近带沟槽连接的304 （目录40 ）不锈钢管的单个外壳。
Before the second cash , the safety mechanism benefit occupant to safe condition . the safety mechanism is very cheap and it can be bought by most consumer . based on the multi - body dynamics roberson - wittenburg formula , a mathematical modle of the " occupant - seat - safety mechanism " system was built , and its kinematic equation was given . the corresponding computer programme was based on the equation , kinematic equation can provide advice for safety mechanism and serve for computer imotion . r / w and kane set up their own formula . they both can prove safety mechanism is benfit to occupant 为了研究人体的伤害机理，选择适当的人体模型作为研究对象；人体采用二维多刚体铰接模型，将人体简化为骨盆、躯干、头部、大腿、小腿、脚部、上臂和前臂八个刚体，而相应的七个关节腰、颈、髋、膝、踝、肩和肘，均简化为带有扭力弹簧和转动阻尼的铰链。
