GOST 8944-75
GOST 8944−75 Connecting parts from malleable cast iron with cylindrical thread for pipelines. Specifications (with Change No. 1)
GOST 8944−75
Group B61
INTERSTATE STANDARD
CONNECTING PARTS FROM MALLEABLE CAST IRON WITH CYLINDRICAL THREAD FOR PIPELINES
Specifications
Ductile iron and steel fittings with parallel thread for pipelines. Technical requirements
ISS 23.040.60
Date of introduction 1977−01−01
The decision of the State standards Committee of the Council of Ministers of the USSR from
Limitation of actions taken by Protocol No. 2−92 of the Interstate Council for standardization, Metrology and certification (ICS 2−93)
INSTEAD 8944−59 GOST, GOST 8945−59
EDITION (September 2010) with amendment No. 1, approved in January 1977 (I & C 2−77)
1. THE CONSTRUCTIVE DIMENSIONS
1.1. The constructive dimensions of fittings with internal threads shall be as specified in the hell.1 and in table.1, and with an external thread — on features.2 and in table.1.
Damn.1. FITTINGS WITH INTERNAL THREAD
FITTINGS WITH INTERNAL THREAD
Option 1
Option 2
_______________
* Dimensions for reference.
Damn.1
Damn.2. A FITTING WITH EXTERNAL THREAD
A FITTING WITH EXTERNAL THREAD
Damn.2
(Changed edition, Rev. N 1).
1.2. The shape and the constructive dimensions of the rib fittings shall be as specified in the hell.3 and in table.1.
Damn.3. The shape and the constructive dimensions of the rib connecting parts
_______________
* Dimensions for reference.
Damn.3
Table 1
Dimensions in mm
Conditional pass |
Thread |
||||||||||||||
| Marking |
| ||||||||||||||
| not less than | |||||||||||||||
| 8 |
G |
13,158 | 9,0 | 9,0 | 7,0 | 13,5 | 12,5 | 2,5 | 3,0 | 3,5 | 3,5 | 3,0 | 2,0 | 3,5 | 2,0 |
| 10 |
G |
16,663 | 10,0 | 11,0 | 8,0 | 17,0 | 16,0 | 2,5 | 3,0 | 3,5 | 3,5 | 3,0 | 2,0 | 3,5 | 2,0 |
| 15 |
G |
20,956 | 12,0 | 14,0 | 9,0 | 21,5 | 20,0 | 2,8 | 3,5 | 4,2 | 4,2 | 3,5 | 2,0 | 4,0 | 2,0 |
| 20 |
G |
26,442 | 13,5 | 16,0 | 10,5 | 27,0 | 25,5 | 3,0 | 3,5 | 4,4 | 4,2 | 4,0 | 2,0 | 4,0 | 2,5 |
| 25 |
G 1 — | 33,250 | 15,0 | 19,0 | 11,0 | 34,0 | 32,0 | 3,3 | 4,0 | 5,2 | 4,8 | 4,0 | 2,5 | 4,5 | 2,5 |
| 32 |
G 1 |
41,912 | 17,0 | 21,0 | 13,0 | 42,5 | 40,5 | 3,6 | 4,0 | 5,4 | 4,8 | 4,0 | 2,5 | 5,0 | 3,0 |
| 40 |
G 1 |
47,805 | 19,0 | 21,0 | 15,0 | 48,5 | 46,5 | 4,0 | 4,0 | 5,8 | 4,8 | 4,0 | 3,0 | 5,0 | 3,0 |
| 50 |
G 2 — | 59,616 | 21,0 | 24,0 | 17,0 | 60,5 | 58,5 | 4,5 | 4,5 | 6,4 | 5,4 | 5,0 | 3,0 | 6,0 | 3,5 |
| (65) |
G 2 |
75,187 | 23,5 | 27,0 | 19,5 | 76,0 | 74,0 | 4,5 | 4,5 | 6,4 | 5,4 | 5,0 | 3,5 | 6,5 | 3,5 |
| (80) |
G 3 — | 87,887 | 26,0 | 30,0 | 22,0 | 89,0 | 87,0 | 4,5 | 4,5 | 6,5 | 6,0 | 6,0 | 4,0 | 7,0 | 4,0 |
| (100) |
G 4 — IN | 113,034 | 39,5 | 39,5 | 30,0 | 115,0 | 112,0 | 5,5 | 5,5 | 8,0 | 7,0 | 7,0 | 5,0 | 8,5 | 4,5 |
Note. The choice of options 1 or 2 are produced by the manufacturer. Preference should be given to the option where it turns the smaller mass of the connecting parts for each .
2. TECHNICAL REQUIREMENTS
2.1. Fittings manufactured in accordance with the requirements of this standard, GOST 8946−75 — GOST 8963−75 working drawings, approved in the prescribed manner.
2.2. Marks and technical requirements for castings — according to GOST 1215−79.
2.3. The outer and inner surfaces of the connecting parts must be cleaned of metal penetration and slag. On uncultivated surfaces are not allowed shell and foreign bodies with a size and in quantities larger than specified in table.2.
Table 2
Dimensions in mm
Conditional pass |
The area of the shell, mm |
The number one product | The depth of the sink | |
| on the body connecting parts |
on the sides of the connecting parts | |||
| no more | ||||
| Up to 15 |
4 | 3 | 1,0 | 2,0 |
| SV. 20 «25 |
6 | 5 | 1,2 | 3,0 |
| „32“ 50 |
8 | 6 | 1,4 | 3,5 |
| „65″ 100 |
10 | 8 | 1,6 | 4,0 |
2.4. Galvanized outer and inner surface of fittings must have a continuous zinc coating (the thread is not is galvanized) no spots, puzyrchatogo inclusions and oxide films. Permitted roughness and local nodules of zinc, provided that there is no delamination of the metal. On the inner surface of allowed yellow and dark spots with a total area not exceeding 5% of the entire inner surface.
2.5. Limit deviations of dimensions for the connecting parts formed by the displacement of the shape at the parting line or rod must not exceed:
| for |
connecting | parts |
|
0.6 mm |
| „ |
“ | “ | St… 15 „25 mm | 0.8 mm |
| “ | » | " | «32 mm | 1.2 mm |
2.6. The bays of the connector shape, technological and other tides on the outer surface of the parts must be stripped. In the angles of crosses, tees and corners are allowed technological tides if they do not extend beyond the ledge, do not have sharp edges and do not damage the marketability of products.
The couplings may increase the height of the ribs, if it serves as the technological tide for the supply of the metal in the form of half its nominal height or local chipped length, not exceeding one-third of the nominal length, in the absence of sharp edges.
(Changed edition, Rev. N 1).
2.7. For the construction of the lengths of the connecting parts are allowed the following maximum deviations:
| for |
length | up to 50 mm | ±1.5 mm | |
| „ |
“ | over 50 | „100 mm | ±2.0 mm |
| “ | » | «100 | «200 mm | ±2.5 mm |
Note. From angles, tees, crosses lengths are distances from the axes of passages until they parallel end planes; couplings, dual nipples, fotorok and similar fittings construction are called their full length.
2.8. Thread fittings — according to GOST 6357−81 (accuracy class). Run away, groove, chamfer, thread — according to GOST 10549−80. Reducing the height of the thread profile at the expense of the top should not exceed 15%.
2.9. External threads allowed a reduction of the useful thread length (without taper) up to 10% against the specified in the standards for specific types of fittings.
2.10. Within the useful thread length allowed thread with an incomplete profile, if in total they amount to no more than 8% of the required thread length.
2.11. Threaded fittings must be clean, free of burrs, ragged or crumpled thread.
2.12. The axis cuts the thread connecting parts should form an angle of 180° or 90 ° depending on their configuration. Deviation of the axes of the cuts from the theoretical axes of the passageways connecting parts shall not exceed 1°.
2.13. Direct couplings and jam nuts one of the face planes must have a parameter of surface roughness of 320 µm according to GOST 2789−73 and to be perpendicular to the axis of slicing. Deviation from Squareness shall not exceed 2°.
Note. According to customer requirements all mechanical plane of the connecting parts must be manufactured with roughness parameter surface 320 µm according to GOST 2789−73.
(Changed edition, Rev. N 1).
2.14. The reduction of thickness of walls against nominal is allowed no more than 20%.
2.15. Fittings without coating and zinc-coated threaded fittings shall be protected from corrosion.
3. ACCEPTANCE RULES
3.1. A fitting present to the acceptance of the parties. The party is composed of connective parts of the same size, simultaneously processed and ready to be handed over.
3.2. The fittings are subject to control appearance, size, quality, coating, mechanical properties of materials and test the strength and tightness.
3.3. Control of coating quality and size allowed to implement the statistical methods.
3.4. Control appearance put every fitting.
3.5. Before the control thread sizes screw sizes the surface should be cleaned or washed.
3.6. Characterization of the mechanical properties of the material of connecting parts of one brand of cast iron and one mode of heat treatment (ponds) to check on witness-samples in accordance with GOST 1215−79.
4. TEST METHODS
4.1. Control of connecting parts in appearance, produce inspection and comparison of samples-standards. Samples-references are selected for each type of defect and approved by the manufacturer.
4.2. Check thread sizes screw sizes are produced according to GOST 1623−89.
(Changed edition, Rev. N 1).
4.3. The alignment of the axes of the threading of the connecting parts is controlled by the measurement of the angle between the segments of pipe screwed tightly into the corresponding passageways connecting parts.
4.4. Perpendicular end plane of the axis of the passage control of the special protractor.
4.5. Fittings are tested for strength test by hydraulic pressure GOST 356−80 during the time required for inspection, but not less than 2 min.
Have transition fittings, pressure is determined by a large passage.
4.6. Fittings (except Hutorok, coupling nuts and lock nuts) should be tested for impenetrability of the air when immersed in water for the time required for detection of defects, excessive pressure, but not less than 5:
0.3 MPa (3 kgf/cm
) for conditional passes of not more than
40 mm;
0.2 MPa (2 kgf/cm
) for conditional passes
of 50−100 mm.
Note. By agreement between manufacturer and user the excess pressure can be increased up to 1.6 MPa (16 kgf/cm
) for conditional passes of not more than
40 mm up to 1 MPa (
10 kgf/cm
) for conditional passes
of 50−100 mm.
4.7. Control mechanical properties of material for fittings shall be made with test specimens according to GOST 1215−79.
If unsatisfactory test results of surveillance specimens fittings shall be tested to the distribution cone. The test subjected 5 of the connecting pieces of each size.
Expansion testing cone made a special mandrel, the size of which should match those in hell.4 and in table.3.
Damn.4 Sizes special mandrel for testing the distribution cone
Damn.4
Table 3
mm
| 15 | 20 | 25 | 32 | 40 | 50 | 70 | 80 | 100 | |
| 20,1 | 25,6 | 31,7 | 40,4 | 46,3 | 58,1 | 73,7 | 86,4 | 111,5 |
Hardness conical mandrel should be below 45 HRC.
The value of the distribution is determined by the output of the end product on the cylindrical part of the mandrel.
The connecting part with external thread (plugs, nipples, etc.), as well as caps and connection nut test on the distribution cone is not exposed.
4.8. The quality of zinc coating dip test of fittings in a neutral solution of copper sulphate in water (1 weight part of CuSO5 parts by weight of distilled water). Dip produce 4 times for 1 min at 15 °C. After each immersion fittings should be rinsed with water and wiped dry. The surface, coated with zinc should not magnatise (to have redness).
5. MARKING, PACKAGING, TRANSPORTATION AND STORAGE
5.1. The marking shall be performed on the coupling parts by casting and contain:
— trademark of the manufacturer;
— the diameters of conditional passes.
Notes:
1. On the intermediate connecting parts denote conditional passes should be from relevant passages.
2. On futerko, lock nuts, double nipple and the connector nut is allowed to apply the trademark and diameter of the conditional passage on the tag.
(Changed edition, Rev. N 1).
5.2. Each batch of fittings accompanied by a passport according to GOST 2.601−95*.
________________
* From 1 September 2006, valid GOST 2.601−2006.
5.3. Fittings of the same size collected in bundles weighing no more than 25 lbs. To the bundle is attached a label indicating data according to claim 5.1.
5.4. Preservation of fittings — according to GOST 9.014−78. Category storage conditions and transportation of, Well, the coolant according to the GOST 9.014−78.
(Changed edition, Rev. N 1).
