Air-O-Unions Mud tank unions have been used for years in piping systems around oilfield drilling rigs all over the world. Drilling mud fluid systems connecting the steel tanks to the pumps need leak proof and quickly detachable connections for large diameter pipe 4” to 16”.
There are basically two types of unions used. The air up type with the tube being aired up seals the pipe. The other types is a large solid o-ring which locks down on the O.D. of the pipe as the hammer nut is tightened Air-o-unions ,Seal-O-Grip