4" Flanged Stainless Steel Reduced Pressure Principle Assembly, NRS Flange, 4ALF21A02

the Apollo model RPLF 4A lead free reduced pressure principle backflow preventers consist of two independently acting, TriForce center stem guided check valves with a differential pressure relief valve located between the check valves. the unit is designed to give maximum protection against backflow of health or non-health hazard fluids by either back-pressure or back-siphonage. the durable domestic stainless steel units (2-1/2"-8") and the FDA epoxy coated ductile iron units (10" and 12") are easily maintained in the line without any special tools. the TriForce check valves operate with a spring assist in the flowing condition to provide excellent flow rates which are documented by an independent laboratory.domestic stainless steel body: 2-1/2" - 8" FDA epoxy coated ductile iron body: 10" & 12"easy maintenance - no special tools requiredsnap-in check retainers: 2-1/2" - 6"bolted-in checks: 8" - 12"low pressure loss as documented by an independent laboratory center-stem guided triforce check valves approved for horizontal flow US Patents: 6,443,184; 7,025,085; 7,533,699; 8,240,333 made in the USA - requires D option5 year warranty