GOST 7909-56

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  ГОСТ 7909-56

GOST 7909−56 drill Pipes exploration and couplings. Specifications (with Amendments No. 1, 2, 3)

GOST 7909−56

Group В62

INTERSTATE STANDARD

OF DRILL PIPE EXPLORATION AND COUPLINGS

Specifications

Prospecting Drill pipes and couplings for them.
Specifications

ISS 23.040.10
OKP 13 1900

Date of introduction 1957−01−01

INFORMATION DATA

1. DEVELOPED AND INTRODUCED by the Ministry of ferrous metallurgy of the USSR

2. APPROVED AND promulgated by the Committee of standards, measures and measuring devices under Council of Ministers of the USSR 29.02.56

3. INTRODUCED FOR THE FIRST TIME

4. REFERENCE NORMATIVE AND TECHNICAL DOCUMENTS

5. Limitation of actions taken by Protocol No. 4−93 of the Interstate Council for standardization, Metrology and certification (ICS 4−94)

6. EDITION with Amendments No. 1, 2, 3, approved in may 1974, June 1984, June 1989 (IUS 6−74, 9−84, 9−89)


This standard applies to seamless steel drill pipes with upset ends and couplings used in geological exploration core drilling.

(Changed edition, Rev. N 3).

I. ASSORTMENT

1. The sizes of pipes should correspond to the features.1 and table.1.

Damn.1

Examples of symbols pipe outer diameter 50 mm of steel grade 36G2S:

a) normalized right thread:

Pipe 50−36G2S GOST 7909−56

b) normalized left-hand thread:

Pipe 50-L-36G2S GOST 7909−56

in) tempered with the right thread:

Pipe-TO-50−36G2S GOST 7909−56

d) hardened with left-hand thread:

Pipe-TO-50-L-36G2S GOST 7909−56

Table 1

Notes:

1. At the ends of the pipe length not more than 300 mm from the pipe end allowed limit deviations of the outside diameter plus or minus 1.45 and 0.95 mm from nominal.

2. Maximum deviations for the internal diameter of the planted part of the pipes: +1 mm, -2 mm, and at end of pipe minus tolerance is limited by size .

3. On the outer surface of the planted portion of the pipe over a length of no more than 300 mm from the end of permitted residual burrs.


(Changed edition, Rev. N 2, 3).

2. Sizes of couplings should correspond to the features.2 and table 2.

Damn.2

Note. It is possible to produce internal threads with ploskosrezannym peaks:

for coupling 42 —=40,1

for couplings 50 —=48,1

for couplings for 63.5 —=60,9

Table 2

Examples of symbols

Couplings of steel grade 36G2S, with the right cutting for pipe outer diameter 50 mm:

Coupler 50−36G2S GOST 7909−56

Couplings of steel strength group D, with left-hand thread for pipe with outer diameter 63.5 mm:

Clutch 63,5-L-D GOST 7909−56

(Changed edition, Rev. N 1, 2).

II. THREAD

3. The profile and dimensions of the thread (both right and left) of pipes and couplings must meet the devil.3 and table.3.

Damn.3

Note. It is possible to produce internal threads with ploskosrezannym peaks:

for couplers 42 and 50 cutting height of 0.6

for couplings for 63.5 — height cutoff of 0.7.

Height of cut vertices is considered from the theoretical sharp thread profile.

Table 3

The dimensions of the thread profile

Notes:

1. Thread pitch measured parallel to the thread axis.

2. The bisector of the angle should be perpendicular to its axis.

3. Value , , , this for the design of the threading tool and the control is not exposed.


(Changed edition, Rev. N 1, 2).

4. Dimensions threaded connections must comply with the devil.4 and table.4.

Damn.4

Table 4

Notes:

1. End of thread end (last line of the thread on the pipe) is considered the end of the continuously vanishing thread of thread.

2. Sizes , , , and are given as reference.


(Changed edition, Rev. N 2, 3).

5. Maximum deviations from the nominal thread sizes are set as (table.4A):

Table 4A

For couplings with a diameter of 42 mm deviations in step length allowed 25.4 mm ±0.06 mm and for all length ±0.12 mm.

For the distance between threads over 25.4 mm permitted deviations increase in proportion to the distance, but not more than 0.10 mm, and for the couplings with a diameter of 42 mm is not more than 0.12 mm.

Maximum deviations of half of the angle profile refer to the corner between the side of the profile and perpendicular to the thread axis of the pipe or coupling.

(Changed edition, Rev. N 2, 3).

III. TECHNICAL REQUIREMENTS

6. Pipe and couplings made in accordance with the requirements of this standard for technological regulations approved in the prescribed manner.

Pipes made of steel strength group K (steel grade 36G2S) or on demand of the consumer steel that provides mechanical properties that match the band strength K.

Table 4B

Chemical composition steel grade 36G2S percentage

Note. Maximum deviations in chemical composition the steels shall meet the requirements of GOST 4543.


(Changed edition, Rev. N 2, 3).

7. Clutch made of steel of strength group K (steel grade 36G2S) or on demand of the consumer steel of other brands, providing the mechanical properties corresponding to higher grades.

8. The pipes are made of normalized.

7, 8. (Changed edition, Rev. N 3).

9. The mechanical properties of the normalized couplings and pipes must comply with table.5.

Table 5

(Changed edition, Rev. N 2, 3).

9a. (Deleted, Rev. N 3).

10. On the surface of the pipes is not permitted flaws, cracks, slivers, and sunsets. Allowed defects, not deducing wall thickness for minimum size and layer of oxides that do not impede the inspection.

(Changed edition, Rev. N 3).

11, 12. (Deleted, Rev. N 3).

13. Napravlennosti the pipe at any section should not exceed 1 mm per 1 m length.

(Changed edition, Rev. N 2).

14. The thread on pipes and couplings should be smooth, without nicks, spalled threads, burrs, flaws and other defects that violate the continuity, strength and density of connections.

The depth of the grooves to exit threading tools in the middle of the coupling shall not exceed the thread depth more than 0,5 mm. Groove should not have sharp corners (undercuts).

In the absence of grooves allowed overcutting counter-thread in the middle of the clutch.

15. Threaded couplings shall be galvanized or phosphated.

(Changed edition, Rev. N 1).

16. The roughness of the thread surface should not be below µm according to GOST 2789.

(Changed edition, Rev. N 1, 3).

17. Deviation of taper along the middle and outer thread diameter of the pipe and the average internal diameter of the thread of the coupler should not exceed 0.12 mm in length .

18. The deviation of the alignment of the threads of both ends of the couplings must not exceed 0.5 mm in the plane of any face and 1.5 mm on a length of 1 m.

19. Tolerances for the interference fit (tab.4) must not go beyond the table.6.

Table 6

To obtain tightness when screwing pipes with couplings allowed the selection of couplings and pipe ends.

Damn.5

Damn.6

(Changed edition, Rev. N 2).

IV. ACCEPTANCE RULES

20. Pipe and couplings present to the acceptance of the parties. The party should consist of pipes and couplings of the same size, one brand or one steel melting and accompanied by one document on quality according to GOST 10692 with the following additions: chemical composition — to document the quality of billets.

The number of pipes with couplings in the party should be no more than 600.

(Changed edition, Rev. N 3).

21. If there is disagreement in the assessment of the chemical composition to verify selected one pipe from the party.

22. Control surface and subjected to size each pipe and coupling.

23. For quality control of tubes and couplings are taken from the party:

5% of pipes and couplings — taper on its outer diameter, outer thread and the inner diameter of the internal threads;

for 5 trumpets and 5 couplings — taper the average diameter of the thread;

5% coupling to check alignment;

one pipe — to control the mechanical properties.

(Changed edition, Rev. N 3).

24. If unsatisfactory test results of at least one of the indicators it is carried out re-testing at twice the sample selected from the same batch.

The results of repeated tests apply to the entire party.

(Changed edition, Rev. N 2).

IVa. TEST METHODS

25. To control the quality from the sample for tensile tests of pipe cut off one sample.

26. The tensile test is carried out for a short proportional specimen according to GOST 10006.

Samples cut from the planted part of the tube in a cold way and not be subjected to any further treatment in the form of forging, pressing, straightening, etc.

Allowed straightening of the clamping of the specimen ends.

Allowed to control the mechanical properties by nondestructive methods.

If there is disagreement monitoring is carried out according to GOST 10006.

27. Inspection of pipes and couplings is carried out visually. Check the depth of permissible defects is carried out with adproval or otherwise in one or three places of the pipe or coupling.

28. The length of the pipe measure tape according to GOST 7502.

29. The taper on the outer diameter of the external thread and the inner diameter of internal thread check respectively smooth calibres-rings and gauges-plugs according to GOST 8993 with the use of probes according to the normative documentation or special devices. Taper the average diameter internal and external threads respectively check devices IVK and INK.

(Changed edition, Rev. N 3).

30. The alignment of the threads of both ends of the clutch check the following method. Check the coupling is screwed together with carefully chopped mandrel exactly centered in the Chuck of a lathe or in a special fixture.

Check the other end of the coupling is screwed with the second mandrel having an accurately ground cylindrical portion with a length of 100−250 mm and coaxial with it chopped part. Rotating clutch, is determined by the indicator with a scale division of 0.01 mm runout of the mandrel at the second end of the coupler and a free end.

30.1. The curvature of the pipes checked straightedge according to GOST 8026. The curvature of a pipe of length not less than 1 m is determined by dividing the deflection of to check the length.

(Changed edition, Rev. N 3).

30.2. Chemical composition of steel is determined according to GOST 22536.0 to GOST 22536.6, GOST 12344 -12357 GOST, GOST 28473 or other methods of equal accuracy standard. Samples for chemical analysis according to GOST 7565.

30.3. (Deleted, Rev. N 3).

Sec. IVa. (Added, Rev. N 2).

V. LABELING, PACKAGING, TRANSPORTATION AND STORAGE

31. Marking, packaging, transportation and storage is carried out according to GOST 10692 with the Supplement.

Pipe complete with couplings, screwed on one end.

At the request of the consumer clutch kit separately.

32. Marking the marking on the three pipes from each packet at a distance of not more than 200 mm from one end and contains the trademark of the manufacturer, month and year of manufacture.

The markings twisted paint.

For designation of steel grades for the tubes (and clutch — if you supply them separately) near the mark applied bands of paint of the color specified by the standard for steel.

Pipe with left-hand thread should have a light belt with a width of 30−40 mm at a distance of not more than 1000 mm from the pipe end.

Clutch with left-hand thread should have a light band in the middle, if they are supplied separately.

31, 32. (Changed edition, Rev. N 3).

33. Threaded pipes and couplings must be protected against corrosion anti-corrosion grease in the normative documentation. External thread tubing shall be protected from mechanical damage protective guards or caps.

(Changed edition, Rev. N 2).