255 Spring Loaded Thief Hatch

Features:

The 255 Spring loaded Thief Hatch is designed
to provide pressure and vacuum relief on liquid
storage tanks and reduce the vapor loss in a 
closed storage system.

The 255 Thief Hatch prevents structural damage
to a tank due to excess pressure or vacuum.
The hatch opens to relieve excess pressure or
vacuum and reseats itself when pressure or
vacuum has dissipated.