End face seal steel tube pressure-measuring method

Abstract

The invention relates to a pressure test method using end-sealed steel tube and is characterized in that the method comprises the following steps: (1) preloading: applying a pressure P1 between a tube to be test and a sealing disc and keeping the P1 equal to KP(test), wherein P(test) is the test pressure of the tube and K is a constant which is determined by the material of sealing disc; (2) increasing pressure: injecting water into the tube to be test to allow the output pressure of the master cylinder to rise along with the increase of water pressure, based on the equation: P 3is multiplied by Pi d(plunger)2 / 4= KP (Pi D2 / 4- Pid2 / 4)+P2is multiplied by Pi d2 / 4, wherein P2 is the pressure of water inside the tube to be test, P3 is the pressure of hydraulic oil inside the master oil cylinder, D is the outer diameter of the tube to be test, d is the inner diameter of the tube to be test, d(plunger) is the diameter of plunger of the master oil cylinder; (3) maintaining pressure: when the water pressure inside the tube to be test reaches to the P(test), maintaining the P(test) unchanged for a time period required in the process; (4) releasing pressure: discharging the high-pressure water from the tube to be test. The invention provides a pressure test method using end-sealed steel tube, provides a theoretical basis for the design and modulation of hydrostatic tester with end seal, and is safe and easy to operate.

Description

technical field [0001] The invention relates to a hydraulic test method for a steel pipe, in particular to a pressure test method for a steel pipe with an end face seal. Background technique [0002] At present, there is an increasing demand for large-diameter steel pipes in the oil and gas industry, machinery manufacturing industry, chemical industry, and metallurgical industry. Most of the methods for testing the performance and quality of steel pipes are internal pressure performance testing. The current pressure test method mainly adopts the radial seal pressure test method for the case that the diameter of the steel pipe is small and the range of change is not large. Sealing is achieved by injecting high-pressure liquid into the sealing chamber to make the sealing material radially deform and lock the steel pipe. Radial sealing is a widely used and mature sealing method in the field of hydraulic testing. For steel pipes with larger diameters, the sealing mold used for...

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