德國寶碩,BUSCHJOST單向閥結構圖

彈簧式:液體由下而上，依靠壓力頂起彈簧控制的閥瓣，壓力消失后，彈簧力將閥瓣壓下，封閉液體倒流。常用于通徑較小的止回閥。

重力式:和彈簧式相似，依靠閥瓣的自身重力封閉，防止倒流。

旋啟式:液體在閥體內直通，依靠壓力頂開一側的旋轉閥瓣，壓力失去后，閥瓣依靠自重回位，反向的液體壓力封閉閥瓣。

塑料隔膜式: 外殼和隔膜均為塑料.一般外殼為ABS,PE,PP,NYLON, PC.隔膜有硅樹脂,氟樹脂等。

其它的單向閥(止回閥)，如排污的止回閥，人防的防爆閥和液體使用的止回閥的原理是大同小異。

旋啟式止回閥適用介質:水，蒸氣，油品，硝酸，強氧化介質和尿素等。廣泛應用于電站，石油，化工，制藥，食品等行業。可與進口設備直接配套使用。對夾式止回閥適用于公稱壓力PN1.0MPa~42.0MPa、Class150~2500;公稱通徑DN12~1200mm、NPS1/2~48;工作溫度-196~540℃的各種管路上，用于防止介質倒流。通過選用不同的材質，可適用于水、蒸汽、油品、硝酸、醋酸、強氧化性介質及尿素等多種介質。

寶碩單向閥實物圖;

德國寶碩,BUSCHJOST單向閥結構圖
engineers practice wellknown in the member countries.
The CE-sign at the valve refers not to the PED. Thus the declaration of
conformity is not longer applicable for this directive.
For valves > DN 25 (G 1) Art. 3 § (1) .4 applies.
The basic requirements of the Enclosure I of the PED must be fulfilled.
The CE-sign at the valve includes the PED. A certificate of conformity of
this directive will be available on request.
The valves of this series, including the connection size DN 25
(G 1), are according to Art. 3 § 3 of the Pressure Equipment Directive (PED)
97/23/EG. This means interpretation and production are in accordance to