16 in PAF450 Manhole Assembly with Nitrile Gasket and Zinc Plated Steel Cover

Model PAF450 features a 10 in (254 mm) reclosing pressure relief valve (PRV) mounted on a center mount 16 in (406 mm) clamp ring style manhole, including a P/V normal vent. The PRV cover doubles as a quick open inspection hatch with a secondary safety catch. The manhole and clamp ring are certified per 49CFR178.345-5 with a test pressure of 36 psig. The PAF450 was legal for installation on US DOT MC306 cargo tanks prior to August 31, 1998. According to 49CFR180.405(h)(2), a functioning PAF450 can be repaired and maintained, but full assembly replacements must meet the less-than 1 liter surge leakage requirement of 49CFR178.345(b)(3)(ii). Therefore, the PAF450 is not permitted as a replacement on MC306 or DOT406 cargo tanks but may be installed on non-specification tanks or tanks operated in countries with permissive regulations. Betts offers PAF406 and PAF306 PRVs that meet the less-than 1 liter surge leakage standard. The PAF450 is also available in a self-latch model (part number 9742 replaces 9716). Self-latch models feature a stop bracket holding the PRV at a 91° position; if left open, tank movement causes the PRV cover to drop and catch semi-closed. The standard model can be converted to self-latching with the 6807SL-KIT1.Manhole, Nitrile (Buna-N) Gasket, Zinc Plated Steel Manhole Cover, PRV Cover: Aluminum, 16 in, Strongback and Latch: Zinc Plated Steel, For PAF450