Abstract: An apparatus and method for shutting off fluid flow in a pipe main while repairs are being made requires only exposure of the top surface of a buried main and utilizes an anchor system installed in or above the excavation which supports an elongate tubular seal tube against the exposed surface of the main to extend radially therefrom. A jack mechanism compresses the lower end of the seal tube containing a seal member against the exterior surface of the main. A tubular cutting tool installed inside the seal tube is rotated by an air motor to cut a hole in the side wall of the main. A tubular sealant application tool installed inside the seal tube has a nozzle at its bottom end that sprays liquid sealant material onto the interior surface of the main and is then removed. A tubular bladder deployment tool installed inside the seal tube carries a pair of deflated bladders.

Abstract: Measurements are taken perimetrically about power or feeder cables at equidistant spaced locations with one or more vibration transducers feeding an electronic measuring circuit sharply tuned to twice the fundamental frequency of the supply system. A substantially flat response around the cable indicates a deenergized cable, while an energized cable produces vibrations that vary sinusoidally in amplitude as the readings progress around the cable.

Abstract: A test stand has a base supporting standards on which are mounted a crossbar and an adjustably locatable header. The header supports an actuator for raising and lowering the crossbar which holds V-blocks for engaging the handles of an impact or impact-rotary tool and which applies downward pressure to the tool. The tool chuck is fitted to the top of a guide rod whose lower end passes with a sliding fit through a disc to which it is keyed and bears against a piston in an hydraulically pressurized cylinder. Sensors detect rotation of the disc and movement of the piston to provide information to a computer as to impact energy and rotary speed. A manifold fitted with sensors for temperature, pressure, and flow rate supplies operating air to the tool. The computer includes a database with stored information as to past history of the tool and the manufacturer's recommended operating specifications to which the measured data is compared.

Abstract: Tool for slitting and laterally expanding underground steel gas mains and inserting replacement plastic piping into the spread apart pipeline has a forward end cylindrical portion mounting a single, rearwardly angled blade to make only one line of cut, and a conical pipe spreader portion at its rearward end. The conical spreader portion is eccentrically disposed with respect to the forward end cylindrical portion. A single roller type pipe slitter aligned with the fixed blade may be mounted on a removable extension of the forward end cylindrical portion, to initially groove and weaken the pipe along the intended line of cut. A pneumatically operated impact ram is attached to the rearward end of the tool, as is the leading end of the replacement piping. A wire cable pulls the tool through the underground pipe, thereby grooving, slitting and laterally expanding the pipe.

Abstract: Tool for slitting and laterally expanding underground steel gas mains and inserting replacement plastic piping into the spread apart pipeline has a forward end cylindrical portion mounting a single, rearwardly angled blade to make only one line of cut, and a conical pipe spreader portion at its rearward end. The conical spreader portion is eccentrically disposed with respect to the forward end cylindrical portion. A single roller type pipe slitter aligned with the fixed blade may be mounted on a removable extension of the forward end cylindrical portion, to initially groove and weaken the pipe along the intended line of cut. A pneumatically operated impact ram is attached to the rearward end of the tool, as is the leading end of the replacement piping. A wire cable pulls the tool through the underground pipe, thereby grooving, slitting and laterally expanding the pipe.

Abstract: A pothead installation for a high voltage, high pressure oil-filled, electric cable in which the pothead is surrounded by a metal tank at ground potential, the tank being filled with sulfur hexafluoride gas under pressure. Oil and nitrogen within the pothead are conveyed to the exterior of the tank by a tube of insulating material having electrical characteristics and a length adequate to withstand at least the voltage difference between the cable conductor and the tank and having physical characteristics adequate to withstand at least the pressures of the oil and nitrogen. At the end of the tube at the tank wall, the tube is connected to a reservoir which is mounted exteriorly of the tank and which accumulates the oil and nitrogen. The reservoir has a venting valve for venting the nitrogen and oil, has a sight gauge for monitoring the oil level in the reservoir, and may have a float switch connected thereto for operating an alarm when the volume of the nitrogen exceeds a predetermined value.