The Betts FVAR416BXB is a 16-inch Model PAF 306-98 manhole designed for MC306 petroleum cargo tanks. This center-mount assembly features an integral 10-inch latch style fill and pressure relief valve with a 3.0 psig set pressure that meets the 1-liter surge leakage limit. The steel zinc-plated manhole cover is secured to the tank weld collar with a clamp ring, bolt, and brass clamping ring nut for easy removal and tank access. The assembly includes a 6238ALB aluminum pressure-vacuum normal vent mounted in the 10-inch relief valve cover, secondary safety latch, and Buna-N gaskets. This manhole provides emergency pressure relief with rated capacity of 250,000 cubic feet free air per hour at 5.0 psig and liquid flow capacity of 1,012 gpm at 5.0 psig.
