GOST 8695-75
GOST 8695−75 Pipe. Test method for flattening (Change No. 1)
GOST 8695−75
Group В69
INTERSTATE STANDARD
PIPE
Test method for flattening
Tubing. Flattening testing method
ISS 23.040.10
Date of introduction 1977−07−01
The decision of the State standards Committee of the Council of Ministers of the USSR from
The expiration time limit is removed by the Resolution of Gosstandard dated
REPLACE GOST 8695−58
EDITION (September 2010) with amendment No. 1, approved in April 1980 (ICS 5−80)
This standard applies to seamless and welded metal pipe with an outer diameter not exceeding 400 mm and with a wall thickness of not more than 15% of the outer diameter of the pipe and establishes a test method for flattening at a temperature of (20±10)°C.
Standard meets the requirements of the CMEA recommendations on standardisation RS 68−63* and ISO recommendation R 202.
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* Access to international and foreign documents referred to here and hereinafter, can be obtained by clicking on the link to the site shop.cntd.ru. — Note the manufacturer’s database.
The standard fully complies ST SEV 480−77 in the test piece for flattening.
1. DESIGNATION
1.1. When tested for flattening includes the following designations:
— the initial outer sample diameter round pipe, mm ;
the wall thickness of the specimen, mm ;
— the distance between the parallel planes at the end of test, mm ;
the inside diameter of the specimen, mm .
2. SAMPLING METHOD
2.1. For testing pipes for flattening used samples in the form of a tube segment with a length of 20−50 mm, and with differences in quality assessment — length of 1.5 , but not less than 10 mm and not more than 100 mm.
2.2. The test can be performed directly on the pipe with its preliminary incision perpendicular to the longitudinal axis to a depth of not less than 0.8 (Fig.1).
Damn.1
2.3. The cutting plane must be perpendicular to the pipe axis. The burrs on the edges of the sample should be removed.
2.4. The sample is allowed to remove the surface layers (inner and outer), if it is stipulated in standards for specific products.
3. TESTING
3.1. For the test specimen is placed between two smooth stiff parallel planes and smoothly flatten it, bringing together the compressive plane to a specified distance (Fig.2 and 3).
Damn.2
Damn.3
3.2. Width of compressive planes should always be greater than the width of the sample after flattening.
3.3. Weld in the tests is approximately 90° to the axis of load application (Fig.4).
Damn.4
3.4. The rate of flattening of the sample due to differences in the evaluation of test quality needs to be not more than 25 mm/min.
4. PROCESSING OF THE RESULTS
4.1. A sign that the sample has withstood the test, is the absence of after the convergence of compressible surfaces to a value on external and internal surfaces of cracks or tears with a metallic luster, assessed visually.
(Changed edition, Rev. N 1).
5. TEST REPORT
In the test report indicate:
— material and pipe size;
— the results obtained.
(Added, Rev. N 1).
