These caps are threaded into the top of stationary (non-mobile) above ground fuel storage tanks, where they serve 2 purposes: a) they can be used as a thread in and lockable fuel filter cap. b) They protect the tank from expansion or implosion, the internal relief valve is normally closed, but opens to relieve internal pressure or vacuum.

Die cast zinc body, brass screen

Pad-lockable to prevent fuel theft and tampering

Not intended for use on mobile tanks. To ensure that the cap can properly vent, the vent cap must be kept free of any debris i.e. dirt, snow, ice, rags etc.

Manufactured to thread into both NPS and NPT tank openings

• Normally closed vent stops fuel evaporation and airborne contaminants
• Protects tank from pressure or vacuum build-up. Relieve pressure at 2 PSI and vacuum at 0.7 HG at a rate of 20 SCFM
• Can be used as a fuel filler cap