Abstract: A tool and method for splitting an existing underground polymeric pipe into a plurality of strips and for expanding the strips and the surrounding ground to permit replacement of the existing polymeric pipe along its length from an entry excavation to an exit excavation without excavating entirely along the length. The tool includes a nose sized smaller than a minimum inside diameter of the existing polymeric pipe, a blade unit attached to the nose having a plurality of cutting blades extending therefrom radially outward about an imaginary central axis, each of the plurality of cutting blades having a forward opened "V" shaped cutting edge sized larger than a maximum outside diameter of the existing polymeric pipe for cutting the existing polymeric pipe into strips along the length thereof.

Abstract: A gas distribution system wherein a plurality of control valves in gas collection lines are actuated by signals of timed duration received from a pressure controller at a control station, the signals being generated in response to changes in gas pressure in a gas distribution network. Timer controlled adjustable cam operated switches control the time duration of signals delivered from the control station to each control valve. Manually actuated switches at the control station are connected to by-pass the controller to simultaneously deliver signals to each control valve such that all of the control valves can be simultaneously actuated. A failure sensing device is a telemeter transmitter to transmit signals related to pressure in the gas distribution network which is equipped with a failure sensing device to deliver signals to the control station to cut out the controller and timer if the transmitter fails for any reason.