GB698366A - Improvements in flame-failure control apparatus for fluid-fuel burning appliances - Google Patents

Abstract

698,366. Testing strength of pipes. HYDRO. PRESS, Inc. June 19, 1951 [June 22, 1950], No. 14541/51. Class 106 (ii). A machine for subjecting tubes to internal fluid-pressure tests and having two sealing heads for engaging the walls of the tubes to be tested in aradialdirectioncomprises a hydraulic intensifier connected at its outlet side to a hydraulic motor capable of displacing one of said sealing heads relatively to the other and means for varying the output pressure of the intensifier. The motor may be arranged to displace one of the necessary end sealing heads of the tube-testing apparatus relatively to the other in such a way that the relationship of the sealing heads to the tube ends remains fixed irrespective of changes in length of the tube during a test. In Fig. 1, a shiftable carriage frame 15 has a test head 10 apertured to receive a pipe 12 within a packing 13. The test head 10 is slidably mounted on a stationary plunger 14 carried by the frame 15. Fluid is supplied to the inside of the tube 12 through a filling or release valve 16 in the frame 15, the valve 16 being operable by hydraulic means 17. Compensating cylinders or motors 18, 19 carried by the frame 15 are connected with the test head 10 by means 20. Associated with the hydraulic system on frame 15 is an intensifier 21, comprising an inlet cylinder 22 and an outlet cylinder 23, the plungers thereof being joined by a pivoted lever 24. The pivoted lever 24 has a fulcrum 25 which is adjustable along the lever 24 by means of a guide 26. As shown in Fig. 3, the lever 24 may have a slot in which the fulcrum 25 can slide. The testing fluid is connected to the inlet cylinder 22 through piping 27, whilst the outlet cylinder 23 is connected through pipes 28, 29 and 30 with the compensating cylinders 18 and 19, respectively. The position of the fulcrum 25 is adjustable to allow the pressure in the outlet cylinder 19 to be varied. With this arrangement, any pressure variations due to the stressing of the tube 12 will be instantaneously reflected in the circuit, such that the motors 18, 19 will cause the head 10 to follow any movement of the end of the tube 12. In Fig. 2, the invention is used for the stationary housing end of the testing machine. A valve operating mechanism 35 is connected to valve 32 for controlling the flow of pressure fluid into the pipe 34 in a sealing head 30. Advance and pull-back hydraulic motors 36 are mounted on the main cylinder 37, a main ram 38 being reciprocable in main cylinder 37. Pistons 39 are connected to cross-head 40 for the purpose of moving the sealing head 30 and valve block 31 as desired. A main ram valve body 41 has a valve 42, controlled by a valve operator 43. The valve 42 is connected through line 44 to the main oil tank or reservoir 45. The lateral cylinders 36 are connected through lines 46 with a source of control fluid for moving the sealing head and as the pressure fluid is introduced into the.cylinders 36, the sealing head will be moved forward. At this time, main valve 42 is open so as to allow the flow of oil from tank 45 into the main cylinder 37. The pressure intensifier is the same as is described with reference to Fig. 1, but its outlet cylinder is connected to the main cylinder 37. The inlet cylinder 48 of the intensifier is connected by line 50 to the source of testing fluid for pipe 34. The arrangement is such that a follow-up of the sealing head 30 occurs if the pressure in the pipe 34 changes due to a shortening of the pipe. During the follow-up movement, the cylinders 36 are inactive. By a proper adjustment of the fulcrum, a pressure will be exerted on main ram 38 proportionate at all times during followup to the pressure generated in the pipe under test, the proportion being small, so that a small but adjustable over-pressure is obtained at the test head.