DOT3X407TWV - 3” NPS female pipe thread, 25# MAWP , 4" HG (2 PSI) Vacuum

FUNCTION
This spring-loaded, dual-acting pressure and vacuum relief
vent provides much needed protection from dangerous
build-up of positive and negative forces, known as pressure
and vacuum, on tank trailers transporting hazardous chemicals.
Each vent is carefully assembled and tested to each customers’
exact specifications. Careful attention was paid to the design
around the idea of a minimization of repair parts and a vent
which could be easily disassembled with simple hand tools.
DISASSEMBLY
Our patented design can be disassembled using our
pressure spring “caging” disassembly feature (See page 4).
This feature effectively “traps” the spring and reduces the
internal pressure enough to allow easy separation of the valve
housings. The main wearable parts are exposed, facilitating
cleaning and repair. The vent can be returned to service within
minutes.