GB/T 5568-2022Rubber or plastics hoses and hose assemblies—Hydraulic-pressure impulse test without flexing (English PDF)

Foreword

This Standard is drafted according to the rules given in the GB/T 1.1-2009.

This Standard replaced GB/T 5568-2006 "Rubber or plastics hoses and hose

assemblies - Hydraulic-pressure impulse test without flexing". Compared with GB/T

5568-2006, the main changes of this Standard are as follows.

- ADD low-pressure impulse test (refer to Chapter 1);

- ADD a reference standard (refer to Chapter 2);

- ADD the terms and definitions (refer to Chapter 3);

- ADD a test chosen temperature (refer to Chapter 6; the Chapter 5 in 2006

edition);

- REVISE test fluid requirements (refer to Chapter 5; Chapter 4 in 2006 edition);

- REVISE expression of the formula for the tested hose free length (refer to 7.2,

1 Scope

This Standard specifies hose impulse test, without flexing, of rubber or plastics

hydraulic hose assemblies at both high and low impulse pressures. The high-pressure

testing is carried out at pressures more than 3MPa and the low-pressure test at

pressures from 1.5 MPa to 3 MPa.

The test procedure applies to hydraulic hose assemblies that are subject to pulsating

pressures in service which are included in the product requirements.

Note. Impulse test procedures with flexing can be found in ISO 6802, "Rubber and

plastics hoses and hose assemblies with wire reinforcements - Hydraulic impulse test

with flexing".

2 Normative references

The following documents are essential to the application of this document. For the

dated documents, only the versions with the dates indicated are applicable to this

document; for the undated documents, only the latest version (including all the

amendments) are applicable to this Standard.

ISO 3448 Industrial liquid lubricants - ISO viscosity classification

ISO 8330 Rubber and plastics hoses and hose assemblies - Vocabulary

ISO/TR 11340 Rubber and rubber products - Hydraulic hose assemblies - External

leakage classification for hydraulic systems

GB/T 5568-2013

3 Terms and definitions

The terms and definitions given in ISO 8330 apply to this document.

4 Apparatus

5 Test fluid

Select a test fluid preferably with a kinematic viscosity from 32 mm2/s to 100 mm2/s at

40 °C (i.e. from grade ISO VG 32 to ISO VG 100 as specified in ISO 3448), and

circulate it at a rate sufficient to maintain a uniform fluid temperature within the test

pieces. Other fluids may be used as agreed upon between the customer and the

manufacturer.

6 Test temperature

The test temperature is normally specified in the referring hose standard. When the

test temperature is not defined in the hose standard, the following temperatures are

the preferred temperatures.

85°C, 100°C, 120°C, 125°C, 135°C, 150°C.

The test fluid shall be circulated through the test pieces at the specified or chosen

temperature with a tolerance of ±3°C. Cooling or heating of the test chamber shall not

be permitted, except when referring standards require testing with synthetic-base test

fluids at a temperature more than 150 °C. When such higher temperatures are

required, the test fluid need not be circulated, provided both the fluid and the test

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