Safety valving for cargo tanks used for bulk transportation of hazardous commodities

Claim 1

Safety valving for cargo tanks used for bulk transportation of hazardous commodities, such as for instance flammables, said valving providing automatic differential pressure relief as well as overturn protection comprising, a housing adapted for attachment to the upper portion of the tank, port means and in said housing adapted for communicating the interior of the associated tank with the exterior, said differential pressure relief including first closure means coacting with certain of said port means and biased to closed condition but being operable to provide automatic differential pressure relief between the interior and exterior of said tank, and said overturn protection including angle responsive closure means responsive to predetermined angular orientation of said valving relative to the vertical and operative to close said valving against inadvertent escape of the tank's contents when the associated tank is in at least partially overturned position, said angle responsive closure means including downwardly converging side wall means on said housing adapted for guiding coaction with a movable closure member coacting with said side wall means and having side wall surfaces formed generally complementary to said side wall means, whereby said closure member is urged by gravity into closed postion relative to confronting of said port means if said valving is displaced into said predetermined angular orientation relative to said vertical, said differential pressure relief means comprising poppet valve means displaceable to open position when the differential fluid pressure between the interior and exterior of the associated tank exceeds a predetermined value, and wherein said valving includes a threaded head section for threading the valving into supporting structure of the tank, said housing including a plurality of circumferentially spaced wells receiving therein spring means and said first closure means including a plurality of ball elements coacting with a respective of said spring means and adapted for reciprocal movement in an associated of said wells, said spring means urging the associated ball element into closed condition with respect to the respective seat of the port means, but being compressible by fluid pressure interiorly of the tank acting on the associated ball element so as to force the ball element into the well against the resistance to compression of the associated spring, said wells guiding the inward movement of the ball element away from its respective seat.