P31:pressures to 3000 psi. Flows to 41 gpm high tensile grey iron, designed for high-torque applications with unique pressure balanced thrust plates that comtribute to optimized performance. P51:pressures to 3000 psi. Flows to 66 gpm high tensile grey iron construction, designed for high-torque applications with unique pressure balanced thrust plates that comtribute to optimized performance. P76:pressures to 3000 psi. Flows to 128 gpm high tensile grey iron construction, designed for high-torque applications with unique pressure balanced thrust plates that comtribute to optimized performance. Roller bearing pumps include models 020, 031, 051 and 076 Features: Pressure balanced thrust plates Durable high-strength cast iron body Contamination tolerant Volumetric efficiencies to 95% Applications: Material handling Turf care Agricultural Construction equipment Valve options: Pressure relief valve Load sense unloading bolt-on relief valve Priority flow divider Trade names: cast iron roller bearing pumps are also marketed under the commercial brand name.