Gas pressure monitoring apparatus

摘要

Gas pressure monitoring apparatus for insertion in a gas container such as a gas pipe (1). The apparatus comprises a valve (17) mounted to a probe (10) an end of which is inserted into the pipe (1). The valve has a keying control knob (21) which cooperates with a guard member (20). The probe (10) is movable along its axis relative to the guard member (20) in order to insert the end of the probe into the pipe (1). The keying cooperation between the valve (17) and guard member (20) prevents the valve from being opened unless the probe (10) is inserted in to the pipe (1).