Abstract: A pipeline break detection system wherein a rate timing device is activated in response to a predetermined pressure drop in the pipeline to direct a signal and activate the on-delay cycle of an energy-blocking device, such as a relay switch in an electric circuit. The timing device then commences an off-delay cycle, and if such cycle continues to completion, it cancels the countdown of the on-delay relay. However, if the pipeline experiences a further like pressure drop, before the timing device completes its cycle, it will be recharged and remain activated to keep the on-delay relay actuated. If the pipeline pressure fails to level off to allow the rate timer relay to close, and the on-delay relay is thus enabled to complete its timed cycle, the relay closes to deliver an electrical signal.

Abstract: A pipeline break detection system wherein a rate timer valve is opened in response to a predetermined pressure drop to direct pressure fluid to activate the time cycle of an on-delay valve and, itself commence a time delay closing cycle. If its closing countdown continues to completion, it depressurizes the on-delay output valve and cancels its countdown. However, if the pipeline experiences a further like pressure drop, before the rate timer valve closes, it will be recharged and held open to keep the output valve timer actuated. If the pipeline pressure fails to level off to allow the rate timer valve to close, and the output relay is thus enabled to complete its timed cycle, the output relay opens to deliver a fluid signal.