Plast-O-Matic RVDT Series anti-siphon and back pressure valves are used in fluid handling systems to redirect or regulate fluid flow. They can withstand pressures up to 150 psi. These back pressure valves feature PVC / 316 stainless steel construction for good mechanical strength and structural rigidity. They feature PTFE seals for preventing leakage and have a zinc-plated steel spring prolonged service life.