Method for sealing or shutting off pipeline using sensor and charge-activated balloon

摘要

The sensor (3) responds to any line pressure drop or surge by activating a propellant gas charge (2) via the control etc. mechanism (4) so as to inflate the balloon from its initially folded condition and so seal or close off the pipeline. The gas cartridge used as charge can be replaced by a gas or oil compressor. A non return valve is used to prevent the balloon penetrating the charge etc. during the inflation phase and an added outlet valve is used to bleed off the balloon pressure once the line fault etc. has been repaired or remedied. A net prevents the balloon sliding along towards the lower-pressure zone and is also used and possibly assisted by a tensile spring etc. to return the balloon to its original state once deflated. The sensor can be adjusted to particular threshold values etc. and the cartridge release mechanism can if need be blocked off either by hand or remotely.