... vary from 1/4''~4'' 3.suitable for joining water,steam,gas and oil pipes 3/8''No291 plugs plain PRODUCT ... in installing and using, and interchange ability. Each malleable cast iron pipe fittings are checked by the atmospheric pressure test, please ... from 1/4''~ 4'', which are suitable for joining water, steam, gas, and oil pipes.B.PROPERTIES AND CHARACTERISITCSMechanical properties: Tensile ...