Valterra 3 Piece Gate Valve [2" Slip x 2" Slip] [40 PSI] [Black] (7201) nipples Union style valves are useful because Union style valves are useful because they allow the valve to be serviced or replaced more easily within the plumbing line This part is useful when the existing top has been dented This version is especially useful in solvent welded systems where the darker body is preferred for a cleaner equipment pad appearance and where future maintenance accessibility matters The Valterra 3 piece gate valve in black is designed for compatible 2 inch slip plumbed systems where a 40 PSI shutoff valve is needed with better serviceability than a simpler body style