The straight threads of the nut engage with the mating threads of the valve outlet and are tightened to compress the gasket between the two sealing surfaces.
螺母的直螺纹同阀门排气口的配合螺纹咬合在一起并上紧，来压缩在两个密封表面之间的衬垫。
2
When installing a pinch valve to a rubber, PVC, or any "slick" mating flange, we recommend that you install a metal serrated gasket between the two flanges to assist in the seal.