JPS5713333A - Method and apparatus for measuring leakage from buried conduit - Google Patents

Abstract

PURPOSE:To accurately, speedily and readily check leakage and the posituion therof independently of ambient vibrations and noises, by measuring the change in flow rate or pressure due to the leakage of the fluid filled under pressure in a buried conduit. CONSTITUTION:A leakage detector 2 is inserted from one end side of a city water pipe 1 to be measured, and said pipe 2 is closed up. Through both conduits C1 and C2, water pressures of the same pressure are applied to the whole inside of the city water pipe and the inside of a leakage- measuring chamber 2c by means of the operation of a pump P. The leakage water along the outer circumferential surfaces of a wire 3 and a feed water pipe 6 both penetrating through closing-up caps 3 is to be minimized, and the pressurizing force is regulatably set through a rlief valve V1 beforehand so that leakage water constantly maintains a set pressure by means of the water for from the pump P. While the insides of the leakage-measuring chamber 2c and the city water pipe 1 are being pressurized by means of the fed water at the same pressure or approximately the same pressure, the wire 4 is wound up around a winding-up drum 5 or the like in order to move the leakage detector 2 through said pipe. On doing this, the deflections of the indicators of respective flowmeters F1 and F2 are read to check whether there is any leakage or not and the position thereof if any.