Pressure discharge valve

摘要

The present invention relates in general to a pressure discharge mechanism for closed vessels having an internal chamber designed to hold volatile and/or explosive substances in a sealed manner comprised of an at least one eutectic composition and a threaded joint designed to open or vent the closed vessel when the contents of the closed vessel reaches a predetermined temperature while maintaining full structural integrity during normal operation. In one aspect, the closed vessel is a munitions casing which functions as intended under normal operating environments, but then when exposed to extreme temperatures, reduces the munition's high order explosion capability, and is transformed into a safe, low order reaction with significantly less reactive potential. In one aspect, the closed vessel is a transport tanker which should not release substances contained therein. However, if the tanker catches fire, the pressure relief mechanism of the present invention reduces risk of explosion.

主权项

1. A pressure discharge mechanism comprising:
a. a valve body having an outer or discharge end and a lower or entry end which is in contact with a closed vessel, the valve body having at least one through hole therein adapted to mate and communicate with a corresponding through hole in a wall of the closed vessel; b. an at least one first vent which automatically provides a partial release of contents within said closed vessel at a first predetermined temperature lower than critical combustion and/or explosive temperatures of said closed vessel contents; c. an at least one second vent which automatically provides a second and greater release of said closed vessel contents through the at least one through hole in the valve body when the contents in the closed vessel reaches a second predetermined temperature higher than the first predetermined temperature but still lower than critical combustion and/or explosive temperatures of the contents of the closed vessel; and d. a solid plug adapted to be connected in threaded engagement with said valve body, whereby to close the at least one through hole therein until the temperature of contents of the closed vessel reaches a critical temperature, said at least one first vent further comprising a vent hole extending through said plug to facilitate a partial release of contents from the closed vessel to the atmosphere, the vent hole in the first vent being provided with a plug formed of a first eutectic composition which seals the vent hole until a first predetermined temperature is reached, said first eutectic composition changing from a solid to a liquid over a predetermined narrow temperature range, thereby melting the solid plug from the vent hole which results in a partial release of liquids from said first vent, said valve body having a through hole which has a smaller diameter in contact with the closed vessel than at the discharge end of the pressure valve, with a shoulder being formed where the diameter of the through hole becomes larger, the smaller discharge hole in the valve body being threaded, said plug conforming in size and shape to the round through hole in the valve body, and fitting in sealing engagement therewith when in threaded engagement with the valve body when a shoulder on the through hole of the valve body is in sealing engagement with a corresponding shoulder formed on the plug, said at least one second vent further comprising a hole extending through the valve body and into said plug, said second vent further comprising an anti-rotational solid plug formed of a second eutectic composition in the hole extending through the valve body and into the plug, said anti-rotational solid plug changing phase from solid to liquid when the contents in the closed vessel reaches a predetermined critical temperature, at which time internal pressure in the closed vessel causes the plug to rotate until no longer in threaded engagement with the valve body and is forced out of the valve body, thus fully opening the valve and relieving excess pressure in the closed vessel.