Hydraulic control system of balance cylinders in hydrostatic test

Abstract

The invention discloses a hydraulic control system of balance cylinders in a hydrostatic test. The hydraulic control system comprises an oil tank, an oil pump, a proportional overflow valve, a main switch, a branch switch and the balance cylinders, wherein an inlet and an outlet of the oil pump are respectively communicated with the oil tank and an inlet of the main switch; the inlet of the main switch is also communicated with the oil tank through the proportional overflow valve; the balance cylinders are communicated with an outlet of the branch switch in parallel; an inlet of the branch switch is communicated with an outlet of the main switch; the balance cylinders are also communicated with a one-way channel which can be used for pumping oil from the oil tank; the proportional overflow valve is in communication connection with two pressure sensors; a test end of one pressure sensor is communicated with the inside of a welded tube to be tested; and a test end of the other pressure sensor is communicated with the outlet of the main switch. According to the hydraulic control system disclosed by the invention, a plurality of balance cylinders are grouped; and any one or several groups are selected and used according to actual requirement, and thereby the action areas of the balance cylinders can be effectively reduced and pre-sealing forces of the balance cylinders are reduced. In the hydraulic control system, the proportional overflow valve is not needed to be replaced and the ascending speed of the pressure of the balance cylinders cannot be reduced; and the operation process is simpler, quicker, safer and more reliable.

Description

technical field [0001] The invention relates to a pipe making unit, in particular to a control system for hydraulic balance in a hydrostatic pressure testing machine. Background technique [0002] The hydrostatic pressure test is the only comprehensive inspection procedure in the key inspection procedure of welded pipe production that can not only inspect the quality of the weld seam, but also inspect the quality of the base metal. Through the hydrostatic pressure test, defects such as cracks, holes, arc breaks, burn-through, and incomplete penetration can be effectively found on the weld seam of the welded pipe and the base metal. [0003] Such as figure 1 As shown, when carrying out the hydrostatic pressure test, one end of the welded pipe 1 is connected to the water filling head 6 through the end seal 7, and the water filling head 6 is respectively provided with a low-pressure water inlet 8 and a high-pressure water inlet 9, and the other end of the welded pipe 1 is conn...

AI Technical Summary

Problems solved by technology

However, the disadvantage of this method is that during the oil and water pressure tracking and balancing process, due to the decrease in the system flow rate, the pressure rise rate of the balance cylinder 2 is reduced, and it is easy to cause the problem that the oil pressure is lower than the water pressure, which will easily lead to seal failure and high pressure water pressure. spray out, and even lead to major accidents

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