GB/T 6111-2018Thermoplastics piping systems for the conveyance of fluids—Determination of the resistance to internal pressure (English PDF)

Foreword

This Standard is identical to ISO 1167.1996 "Thermoplastics pipes for the conveyance

of fluids - Resistance to internal pressure - Test method" (English version). The

technical content is the same and the preparation method is identical, only editorial

modifications in the text are made.

This Standard replaces GB/T 6111-1985 "Standard test method for time-to-failure of

thermoplastic pipe under constant internal pressure".

Compared with GB/T 6111-1985, this Standard has the following main changes.

1 CHANGE the standard name from the "Standard test method for time-to-failure of

thermoplastic pipe under constant internal pressure" TO "Thermoplastics pipes for

the conveyance of fluids - Resistance to internal pressure - Test method".

2 ADD the clause of test parameters.

3 IMPROVE the accuracy requirements for test apparatus.

4 DELETE type C end caps; describe the other two types of end caps in detail.

5 CHANGE the number of test pieces to 3 and specify the length of test pieces.

6 SPECIFY the method and duration of conditioning of test pieces.

7 SPECIFY the treatment method for different test phenomenon during the test

process.

8 ADD the informative Annex A.

This Standard replaces GB/T 6111-1985 from the date of implementation.

Annex A of this Standard is informative.

This Standard is proposed by China Light Industry Federation.

This Standard is under the jurisdiction of National Technical Committee on Plastics of

Standardization Administration of China (TC 48).

Drafting organizations of this Standard. Zhejiang Yonggao Plastic Industry

Development Co., Ltd., Hebei Baoshuo Pipe Co., Ltd.

Main drafters of this Standard. Huang Jian, Zhao Zhijie, Xu Xuecheng, Wang Shuhua,

Jiao Cuiyun.

Thermoplastics pipes for the conveyance of fluids -

Resistance to internal pressure -Test method

1 Scope

This Standard specifies a method for determination of the resistance of thermoplastics

pipes to constant internal water pressure at constant temperature.

This Standard is applicable to thermoplastics pipes intended for the conveyance of

fluids.

2 Normative references

The following standards contain provisions which, through reference in this text,

constitute provisions of this Standard. At the time of publication, the editions indicated

were valid. All standards are subject to revision, and parties to agreements based on

this Standard are encouraged to investigate the possibility of applying the most recent

editions of the standards indicated below.

GB/T 4117-2001 Thermoplastics pipes for the conveyance of fluids - Nominal

outside diameters and nominal pressures (idt ISO 161-1.1996)

GB/T 8806-1988 Method for dimension measuring of plastic pipes (eqv ISO

3126.1974)

GB/T 18252-2000 Plastics piping and ducting systems - Determination of the long-

term hydrostatic strength of thermoplastics materials in pipe form by extrapolation

NOTE. GB/T 18252-2000 "Plastics piping and ducting systems - Determination of the long-

term hydrostatic strength of thermoplastics materials in pipe form by extrapolation" is

developed referring ISO/DIS 9080.1997 "Thermoplastics pipes for the transport of fluids -

Methods of extrapolation of hydrostatic stress rupture data to determine the long-term

hydrostatic strength of thermoplastics pipe materials", so the technical content of this

standard is identical to ISO/DIS 9080.1997.ISO/DIS 9080.1997 is the revision to ISO/TR

9080.

3 Definitions

For the purposes of this Standard, the definitions given in GB/T 4217-2001 apply.

4 Principle

After conditioning, test pieces are subjected to a specified constant internal hydrostatic

pressure to a specified period of time or until failure.

Throughout the test, the test pieces are kept in an environment at a specified constant

temperature. this is water ("water-in-water" test), another liquid ("water-in-liquid" test)

or air ("water-in-air" test).

5 Test parameters

The following test parameters are set by the standard making reference to this

Standard.

a) the type of end cap to be used (see 6.1);

b) the size and S-series of pipe to be used (see 7.1);

c) the test temperature (see 6.2 and 10.1);

d) for pipes of nominal outside diameter dn greater than 315 mm, the free length of

the test piece, if other than 1 000 mm (see 7.1.1);

e) the number of test pieces (see 7.2);

f) the test pressure p or the hoop stress sigma to be induced by the test pressure (see

8.2.2);

g) the conditioning period (see clause 9), if other than as specified in table 1;

h) the type of test, i.e. water-in-water/air/liquid (see clause 4 and 10.1);

i) the duration of the test under pressure and the criteria for a failure (see 10.3);

j) the requirements for additional testing.

6 Test apparatus

7 Test pieces

000 h can be continued providing the equipment is reinstated within 3 days. For tests

which have been under way for more than 5 000 h, the test can be continued providing

the equipment is reinstated within 5 days. Following equipment failure, if the test pieces

are closed off at the test pressure by a solenoid valve or other means the test can be

continued in the event of periods of breakdown in excess of that stated above. It should

be noted that, in this situation, the pressure will gradually decrease due to continuing

Creep in the test piece. The time whilst the equipment is not able to function normally

shall not be included in the test time.