which are situated on the closing body and are resting on the valve seat 9 in off position are to make the device gas tight the closing body 39 s 10 axial extension 15 projects into the outlet socket 3 the base plate 4 fixed to the curtain wall 7 has several catch elements 16 protruding from the perimeter on which they are equally spaced when mounting a bonnet 18 covering over the base plate 4 said catch elements will lock into assigned openings 17 provided in the bonnet 18 the bonnet 18 shown in fig2 in a partly cut away view has a long hole 19 in its front side where the outlet socket 39 s 3 connector opening 20 is situated behind said long hole 19 covering part of it a slider 38 that serves as a cover 21 is situated between bonnet 18 and base plate 4 where it is guided so that it can freely move along its longitudinal axis a spring 22 the one end of which rests on the bonnet 18 and the other one on the slider 38 exercises forces in the slider 39 s 38 moving direction and by doing so causes the slider 38 to close the long hole 39 s 19 area that makes the outlet socket 39 s 3 connector opening 20 accessible in such a way that the slider 38 and the non closed long hole 19 area form a precisely dimensioned uptake opening 23 to take up a gas connector plug 24 the rectangular slider 38 as shown in fig3 as a separate detail has on one of its two face sides a dome 25 formed by two crossing ribs that serve to take up and at the same time guide.