Detailed Product Description Figure 400 Hammer Union, 4000PSI Nominal pipe Size:2'', 2-1/2'', 3'',4'',6'',8'',10'',12'';Pressure Rating:4000psi cwp;6000 psi test;Connections Type: pipeline thread, tubing thread, butt-weld;Component Parts: Nut, Male Sub, Female Sub, Seal Ring;Sour Service Models to NACE MR-01-75.Recommended serviceManifold and line connections, pump suction, and mud service.