GOST 11706-78
GOST 11706−78 Pipe. Test method for a hand ring cone (with Change No. 1)
GOST 11706−78
Group В69
INTERSTATE STANDARD
PIPE
Test method for a hand ring cone
Tubes. Method the tensile test of ring by cone
ISS 23.040.10
Date of introduction 1979−07−01
The decision of the State standards Committee of the Council of Ministers of the USSR from
Limitation of actions taken by Protocol No. 7−95 Interstate Council for standardization, Metrology and certification (ICS 11−95)
REPLACE GOST 11706−66
EDITION (September 2010) with amendment No. 1, approved in April 1980 (ICS 5−80)
This standard covers metal pipe of circular cross section with a wall thickness of from 2 to 8 mm inclusive and a diameter of from 18 to 150 mm and sets the method of static tests on the distribution ring conical mandrel at a temperature of (20)°C.
The standard fully complies with the recommendations of the CMEA PC 68−63 and ISO recommendation R 166*.
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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 part of the test for a hand ring cone.
(Changed edition, Rev. N 1).
1. SAMPLING METHOD
1.1. To test the distribution from the end of the pipe cut samples in the form of a ring with a height from 10 to 16 mm.
1.2. The cutting plane must be perpendicular to the longitudinal axis of the ring. Sharp edges at the ends of specimens shall be rounded and burrs removed.
1.3. The samples before testing should be covered with any grease.
2. EQUIPMENT
The test is carried out on universal testing machines or other press equipment that provides the speed of advance of the mandrel when tested not more than 30 mm/s.
Diagram of the device for the test is given in the Appendix (DWG.1 and 2).
Used mandrel for expansion testing shall meet the following requirements:
the working surface of the mandrel shall have a hardness not less than 50 HRC;
— the roughness parameter of the surface of the mandrel shall be not more than 20 µm according to GOST 2789−73;
the mandrel before the test, should be covered with grease.
For tests used a mandrel with a taper of 1:10 or 1:5.
It is possible to use a mandrel with the taper of 1:4 and the mandrel cone with an angle equal to 30°.
3. TESTING
3.1. The test is carried out by a smooth distribution of the sample in a conical mandrel or a mandrel with a cylindrical portion according to GOST 8694−75 to an open or to a predetermined percentage distribution. The test procedure for a hand ring cone given on features.3 and 4 applications.
3.2. A test of the distribution ring is held by:
— before the rupture;
up to a certain size distribution (in percent).
Kind of test are indicative of normative-technical documentation for pipe.
3.3. On the mandrel to the cylindrical portion is permitted to simultaneously test up to five rings.
3.4. When testing ring to a predetermined value of the distribution with greatest external diameter of the ring () after the test is calculated by the formula
where is the outer diameter of the ring to the test.
3.5. The largest outer ring diameter measured after the test at the end of the input side tapered mandrel with an accuracy of 0.1 mm.
3.6. Indication that the sample passed the test, is the distribution of it by a given value and the absence of internal and external surfaces after the test, cracks or tears with a metallic sheen.
When you test a ring to the gap assessment is also performed and fracture surface (in the absence of fracture, captivity, cracks, tears, sunsets and bundles).
3.7. Control of the sample surface or of fracture is made visually without the use of magnifying means if the normative-technical documentation for pipe otherwise.
4. TEST REPORT
In the test report indicate:
— material and size of pipe;
— the results obtained.
(Added, Rev. N 1).
APPLICATION (recommended). Diagram of the device for the test
APP
Recommended
1 — conical mandrel; 2 — ring; 3 — split bushing; 4 — compression springs
Damn.1
1 — conical mandrel; 2 — ring; 3 — rack; 4 — the base
Damn.2
1 — conical mandrel; 2 — ring samples
Damn.3
1 — mandrel with a cylindrical part; 2 — ring samples
Damn.4
