止回阀：止回阀又称单向阀或逆止阀，其作用是防止管路中的介质倒流。水泵吸水关的底阀也属于止回阀类。启闭件靠介质流动和力量自行开启或关闭，以防止介质倒流的阀门叫止回阀。止回阀属于自动阀类，主要用于介质单向流动的管道上，只允许介质向一个方向流动，以防止发生事故。止回阀按结构划分，可分为升降式止回阀、旋启式止回阀和蝶式止回阀三种。升降式止回阀可分为立式和卧式两种。旋启式止回阀分为单瓣式、双瓣式和多瓣式三种。蝶式止回阀为直通式、以上几种止回阀在连接形式上可分为螺纹连接、法兰连接和焊接三种。高压升降式止回阀主要零件材料零件名称材料牌名阀体WCBZGCr5MoZG1Cr18Ni9TiZG1Cr18Ni12Mo2Ti阀盖WCBZGCr5MoZG1Cr18Ni9TiZG1Cr18Ni12Mo2Ti阀瓣WCBZGCr5MoZG1Cr18Ni9TiZG1Cr18Ni12Mo2Ti垫片石墨缠绕垫片石墨缠绕垫片聚四氟乙稀缠绕垫片聚四氟乙稀缠绕垫片高压升降式止回阀型号性能规范公称压力壳体材料试验压力(Mpa)PN（MPa）WCBZGCr5Mo(C5)ZG1Cr18Ni9TiZG1Cr18Ni12Mo2Ti强度试验液体密封气体密封1.6H41H-16CH41Y-16IH41W-16PH41W-16R2.41.82.5H41H-25H41Y-25IH41W-25PH41W-25R3.82.84.0H41H-40H41Y-40IH41W-40PH41W-40R6.04.46.4H41H-64H41Y-64IH41W-64PH41W-64R9.67.110.0H41H-100H41Y-100IH41W-100PH41W-100R15.011.0适用温度-29-425℃≤550℃-40-200℃-40-200℃超出温度范围，请订货时注明适用介质水蒸气、油品等水蒸气、油品等硝酸等醋酸等高压升降式止回阀连接尺寸和外形尺寸型号公称通径(mm)尺寸(mm)LDD1D2D6bZ-￠dD0HH41H-4080310195160135121228-￠18200170100350230190160150248-￠23230195125400270220188176288-￠25270225150480300250218204308-￠233302552006003753202822603812-￠30405318H41H-6415170105755540204-￠14757520190125906851224-￠18110110252101351007858244-￠18125125322301501108266244-￠23152152402601651259576244-￠231681685030017513510588264-￠2317017065340200160130110288-￠2318818880380210170140121308-￠23205205100430250200168150328-￠25230230H41H-10015170105755540204-￠1410010020190125906851224-￠18110110252101351007858244-￠18125125322301501108266244-￠23140140402601651259576264-￠231701705030019514511288388-￠2518518565340220170138110328-￠2520020080380230180148121348-￠25235235100430265210172150388-￠30265265)