F646 Vent Valves

Meggitt F646 Series 5.25 inch vents are designed in accordance with DOT MC306 specifications and will mate with a standard 4-inch TTMA sump ring. The venting capacity is 304,000 cu. ft/hr at five PSI and the cracking pressure is three PSI. The F646 vent is available in air and mechanically operated configurations.

No moving parts in high level control • 4-inch internal valve mates NTT standard flange-removable from outside. 6-inch valve furnished with steel welding ring (mounting does not mate with NTT flange). Stainless steel ring optional • Soft closure feature for surge control • Loading and off-loading through one valve • Fail closed system • Lightweight design • Air operation for off-loading • Modular pilot construction for ease of maintenance. • Low pressure loss: Bottom Loading 4-inch - 4.5 psi at 600 gpm 6-inch - 4.5 psi at 1200 gpm Off-Loading 4-inch - 1.5 psi at 600 gpm 6-inch - 0.75 psi at 1000 gpm • Functions properly with inlet pressures to 200 psi • Internal valves can also be used with F619 three-way float pilot valve