Protectoseal - Model 3908-SL - Pressure & Vacuum Relief Thief Hatch - Brochure

Pressure & Vacuum Relief Thief Hatch provides ready access to the tank interior for inspection, gauging or sampling operations. The unit also provides pressure and vacuum relief of the tank’s vapor space through integral, spring-loaded pressure and vacuum relief mechanisms. Valves open and close to permit only that intake or outlet relief necessary to keep interior pressure within permissible working limits.