this pressure control device , more particularly for use in pyrotechnical load ejectors of the type used for jettisoning loads on aircrafts , comprises an easily detachable block consisting of a main body and of detachable component elements secured to the main body , the latter comprising a bore for the sliding mounting of a spool valve urged by a return spring for automatically limiting the downstream pressure delivered to the pyrotechnical impellers mounted in cavities of the main body , other component elements secured laterally to the body permitting when removed an easy access to the gas passages for cleaning purposes .