Comparison : Item # Model 71S, Iron, Steel, Stainless Steel Relief Valves for Liquid Service
Item # Model 171, Iron, Steel, Stainless Steel Relief Valves for Liquid Service
Item # Model 171P, Iron, Steel, Stainless Steel Relief Valves for Liquid Service
Item # Model 171S, Iron, Steel, Stainless Steel Relief Valves for Liquid Service