The Rotary (P.N.) Union has the same basic design as the Rotary (L.C.) Union but incorporates an oil lubrication reservoir for seal face lubrication. This unit is intended for use on pneumatic applications where the compressed air is dry. This unit may also be advantageous compared to the Rotary (L.C.) Union even on lubricated air systems where speeds are high and only occasional pneumatic cycles are in use. Under these conditions very little lubricant reaches the seal faces and is quickly dissipated by the seal face temperatures created by natural friction. Pneumatic applications are, in the main, single flow consequently only this type is offered.