Rapidair REFRIGERATED, 60 CFM, 3 4", 115V length_96 in Graco 239937 Piston Valve Restock your HazMat Quick Graco 239937 Piston Valve 36 Maximum Regulated Pressure (bar) 4 Maximum Regulated Pressure (kPa) 400 Maximum Regulated Pressure (psi) 60 Maximum Viscosity (cP) 1000 Maximum Working Pressure (bar) 18 Maximum Working Pressure (kPa) 1800 Maximum Working Pressure (psi) 250 Minimum Regulated Pressure (bar) 0 Minimum Regulated Pressure (kPa) 0 Minimum Regulated Pressure (psi) 0 Outlet Size (cm) 0 Other than keeping the heat exchanger clean from dust and conducting regular filter element changes The Pre Filter (P) is a 1 micron general purpose filter that protects the dryer and high performance 3 in 1 heat exchanger from dirt and oil