GB869514A - Improvements relating to fluid actuated testing apparatus - Google Patents

Abstract

869,514. Testing strength of hollow-ware. PORTABLE BALES Ltd. March 2, 1959 [March 4, 1958; May 27, 1958(2)], Nos. 6835/58, 16774/58 and 16775/58. Class 106 (2). [Also in Group XXVIII] Fluid pressure-actuated testing apparatus comprises a body 10 provided with high and low pressure cylinder B, A, a differential ram 11 for displacement within the cylinders, a pipe line 17 incorporating a non-return valve 16 for connecting the high pressure cylinder B to a source of fluid pressure, and a control valve 19 for controlling a supply of fluid under pressure to the low pressure cylinder A, spring means 25 or fluid pressure means (not shown) associated with the low pressure cylinder being provided for assisting in the return of the differential ram 11 to its initial position. A tap 24 to be tested is mounted on a pipe 22, which forms one of the four arms of a union 103, the others being connected to a supply pipe 17, the high pressure cylinder B and a pressure gauge 14 respectively. In use, mains water is supplied through the pipe 17 and the non-return valve 16 to fill the cylinder B and the tap 24, thus subjecting the tap to an initial test at mains pressure. Subsequently, the valve 19 is opened to supply air under pressure to the pressure side 113 of the low pressure cylinder A, thus generating a higher pressure in the cylinder B for a pressure test at, for example, 300 lb./sq. in. When the test is completed, the mains water supply is turned off, the valve 19 operated in order to exhaust the air from the cylinder A and the valve of the tested tap 24 opened. This tap is then removed and another placed in position. A coiled spring 25 returns the ram 11 to its initial position when the cylinder A is exhausted. In other embodiments, a second differential ram may be used to obtain a higher pressure; the taps may be tested at two pressures, e.g. 350 lbs./sq. in. and 625 lbs./sq. in. by the use of two pressure controllers connected in parallel in the air supply line; and the spring 25 may be omitted, the exhausted air from the cylinder A being directed into the left-hand side of the cylinder to cause retraction of the ram 11. A device for mounting a range of straight through valves of various lengths is also described (Fig. 6, not shown), a further differential piston device being used to obtain a sealed joint under the testing pressure. If desired, all the testing may be performed under hydraulic or under pneumatic pressure. The apparatus may also be used for testing tubes and gas cylinders.