RU2636812C2 - Method of external hydrostatic load test of sheath - Google Patents

Abstract

FIELD: testing equipment.

SUBSTANCE: method consists in placing the product in a compression container, which is arranged on the principle of a hydraulic multiplier, and installing this container in the deepening in the water area. In this case, the design of the compression container and the manner in which the test article is placed in it allow the pressure to be automatically increased in comparison with the pressure in the external environment in which this container is located.

EFFECT: expansion of the technological capabilities of the work, which can be carried out at smaller depressions in the water area.

1 dwg

Description

The invention relates to a test technique, and in particular to methods of testing external hydrostatic pressure, and can be used in technical fields where products are used that work when exposed to external hydrostatic pressure, for example, underwater vehicles.

With the well-known method of external hydrostatic pressure testing, the test shell is directly placed in a high-pressure chamber or installed on a predetermined recess, where the hydrostatic test pressure of the required value is created (environmental pressure).

There is a method when, in order to facilitate the selection of fracture fragments, the test shell is first placed in a bag or a rigid leaky vessel, and already in them they are placed in a high-pressure chamber or mounted on a recess.

The closest technical solution, selected as a prototype, is the “Method of testing the shells with external hydrostatic pressure” [3], in which, in order to prevent the occurrence of a hydraulic shock when the tested hollow shell is destroyed, the latter is first placed in a liquid-filled split vessel with a calibrated hole, that is, leaky, and then in this vessel is installed in the high-pressure chamber.

A common feature and common disadvantage of the known methods considered is the fact that the maximum possible value of the test external hydrostatic pressure acting on the test shell cannot exceed the permissible working load in the high-pressure chamber or the depth of the location in the water area.

The aim of the invention is to create conditions under which the value of the test external hydraulic pressure acting on the test shell automatically increases in comparison with the hydrostatic pressure generated in the high pressure chamber or in the recess.

This goal is achieved by the fact that the test product is first placed in a compression container arranged on the principle of a hydraulic multiplier, and in this container it is mounted on a recess, while the device of the compression container and the method of installing the test casing in it ensure the fulfillment of the task - an automatic increase in the test pressure compared with the pressure of the external environment by a certain amount determined by the design of the compression container.

The test scheme for the proposed method, the schematic structure of the compression container and the installation scheme of the test shell in it are presented in the drawing. The compression container has two chambers of different diameters - a test chamber (1) of a smaller diameter - d and a load chamber (2) of a larger diameter D.

The chambers are disconnected by longitudinally sealed rubber seals (8) and a longitudinally movable two-stage piston (4). The test shell (5) is placed in the test chamber (1), the free volume (3) of which is completely filled with liquid, while the test chamber is sealed against the external environment (6). The space (7) above the piston at the load chamber is open to the external environment (not tight). The internal free space (9) between the chambers is hermetically sealed against the external environment (6) and the liquid (3) in the test chamber. When installing a compression container with the test shell (5) on the recess, the hydrostatic pressure q _in arising in the external environment (6) acts on the outer surface of the piston (4) with a diameter D and automatically (due to the difference in the diameters of the chambers) creates in the test chamber (1) test pressure q _and equal to q _and = (D / d) ² × q _in (where q _and is the test pressure, D is the piston diameter of the load chamber, d is the diameter of the test chamber, q _in is the hydrostatic pressure of the external environment), t. e. pressure is greater than that acting in the external environment (6). Therefore, the proposed method for testing products with external hydrostatic pressure in the water provides the goal - creates the conditions under which the test hydrostatic pressure on the shell automatically increases compared to hydrostatic pressure in the external environment.

Thus, the difference between the claimed method and the known ones is that in the claimed method the test pressure on the shell exceeds the pressure of the external medium that has arisen on the recess by a certain amount determined by the design of the compression container arranged on the principle of a hydraulic multiplier, in which the shell placed for testing is placed .

The applicant does not know examples of the use of hydraulic multipliers or the existence of any other ways to solve the problem - to automatically increase the test pressure compared to the pressure in the environment in which the tests are carried out.

The technical problem solved by the proposed technical solution is to create the possibility of testing at pressures exceeding the pressure of the external environment.

The technical result obtained by the implementation of the proposed technical solution consists of:

- the ability to expand the range of applications of existing high-pressure chambers, eliminating the need to create new ones with greater workload;

- the ability to organize aquatic tests in shallow protected and equipped inland water bodies, that is, to increase the information content and reliability of work and reduce the cost of access to deeper neutral waters.

Information sources

1. OST 92-4291-78.

2. Seregin M.Yu. Test methods and devices, test organization and technology, part 1. Study guide, p. 45.

3. A.S. USSR No. 1456827 for an invention, IPC G01N 3/12, publ. 02/07/1989.

Claims (1)

A test method for shells by external hydrostatic pressure, characterized in that the test shell is preliminarily placed in a compression container arranged on the principle of a hydraulic multiplier, and already in this container is installed on a recess in the water area, while the container design and the method of placement of the tested product in it automatically increase the magnitude of the external hydrostatic pressure on the test shell compared with the hydrostatic pressure created at the recess n and a value depending on the design of the compression container.

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