GOST 20900-75

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  ГОСТ 20900-75

GOST 20900−75 Pipe waveguide copper and brass rectangular. Specifications (with Amendments No. 1, 2, 3)

GOST 20900−75
Group В64

STATE STANDARD OF THE USSR

THE WAVEGUIDE TUBE COPPER AND BRASS RECTANGULAR
Specifications
Copper tubing for waveguides and brass right angle tubes.
Specifications.

GST 18 4000

Valid from 01.01.76
before 01.01.96*
_______________________________
* Expiration removed
Protocol 5−94 N Interstate Council
for standardization, Metrology and certification
(IUS N 11−12, 1994). — Note the CODE.

INFORMATION DATA

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

DEVELOPERS

L. P. Seleznev, candidate. tech. Sciences; M. B. Taubkin, PhD. tech. science; N.With.Izvolsky

2. APPROVED AND promulgated by the Decree of the State Committee of standards of Ministerial Council of the USSR from 14.06.75 N 1508

3. REFERENCE NORMATIVE AND TECHNICAL DOCUMENTS

4. Validity extended until 01.01.96 by the Resolution of Gosstandart of the USSR No. 1425 from 06.06.90

5. REISSUE with Amendments No. 1, 2, 3 approved in April 1979 April 1984 June 1990 (IUS 5−79, 7−84, 9−90)


This standard applies to pipe copper and brass, drawn, rectangular, designed for the manufacture of waveguides.

(Changed edition, Rev. N 3).

1. ASSORTMENT

1.1. Shape, dimensions and tolerances for sizes shall be as specified in the drawing and in the table.

Drawing

Notes:

1. Pipe sizes are indicated in parentheses in the new development do not apply.

2. By agreement with consumer it is permitted to supply pipes measuring and multiple gauge length.

3. Tube section 7,2x3,4 mm or more brass brands L63 must be manufactured with a length of not less than 1 m, the small — less than 0.5 mm.

4. Allowed small pipe not more than 15% of the batch weight.

5. On customer requirement tube section 48х24, 58х25, 72х34, (72х44), 90х45 mm are made with wall thickness of (5±0,5) mm inside radius of curvature () is not more than 0.7 mm, an outer radius of 4 mm.

6. Theoretical weight of 1 m of pipes given in the Appendix.

7. By agreement with the consumer can be made of the pipe size 23х10х1 mm brass brands L63, and a size 28,5x12,6x1,5 mm brass brand l96 with the limit deviations on width and height of the inner cross section of ±0,06 mm.

8. Allowed by agreement between manufacturer and consumer to manufacture pipes with dimensions of the inner section 5,2x2,6 and with an angle of 90±1°30'.


(Changed edition, Rev. N 2, 3).

The symbol pipe is stamped as follows:

when the following abbreviations:

Examples of symbols

The pipe is drawn, rectangular, normal accuracy of production, firm size section 248х124 mm, wall thickness 3 mm, length 3000 mm, copper, grade M3:

Pipe DPRNT 248х124х3х3000 M3 GOST 20900−75

The same manufacturing high precision, solid, size 16x8 mm, with a wall thickness of 1 mm, random length brass brands L63:

Pipe DPCT 16х8х1 ND L63 GOST 20900−75

Same, the normal precision manufacturing, rigid, size section 40х5 mm, with wall thickness of 1.5 mm and a length that is a multiple of 1500 m, brass brand l96:

Pipe DPRNT 40х5х1,5х1500 CD l96 GOST 20900−75 .

(Changed edition, Rev. N 2).

2. TECHNICAL REQUIREMENTS

2.1. Pipe shall be made of copper grades M2, M3 according to GOST 859−78 and brass brands L63 and l96 according to GOST 15527−70.

Pipe manufactured in accordance with the requirements of this standard for technological regulations approved in the prescribed manner.

2.2. Pipe manufacture in the solid state. Pipe brass brands L63 subjected to low temperature annealing.

2.3. The outer surface of the pipe should not have cracks and delamination. Not allowed slivers, dents, shells, scratches, scores and nicks, if they control the sweep output tubes for limit deviation for wall thickness.

On the surface of the pipe allowed the color of the tint and redness.

2.1−2.3. (Changed edition, Rev. N 2).

2.4. Inner surface of the pipe must be smooth and clean, must not have captivity, sinks, cracks, nicks, delamination, dents, scratches and scuffing. The surface roughness of the pipe manufacturing high precision should be not more than 0,63 mm according to GOST 2789−73. At the customer’s request roughness of the inner surface of the tube normal manufacturing precision should be not more than 2.5 µm according to GOST 2789−73.

The longitudinal traces of the drawing, the small surface ripples caused by lug, color tint, redness are not signs of rejection. In coordination with the consumer the quality of the surface set samples approved in the established order.

(Changed edition, Rev. N 2, 3).

2.5. The pipes must be trimmed evenly and must not have burrs.

Cut end Squareness, mm should not exceed:

3 mm — for tubes with an inner cross section of 90х45 mm or less;

6 mm — for tubes with internal cross-section over 90х45 mm to 180х90 mm, inclusive;

8 mm — for pipes with an inner cross section over 180х90 mm.

2.6. Curvature and torsion on 1 m length of the pipes must not exceed:

1 mm — for tubes internal dimensions 2,4x1,2 to 5,2x2,6 mm, inclusive;

2 mm — for tubes with internal dimensions: 7,2x3,4 to 35х15 mm, inclusive;

2.5 mm — for tubes with internal cross-sections from 40х5 to 48х24 mm, inclusive;

3 mm — for tubes with internal cross-sections from 58х10 to 90х45 mm, inclusive;

4 mm — for tubes with internal cross-section over 90х45 mm.

Note. On customer requirement tube section over 90х45 mm is supposed to produce curvature and twisting of no more than 3 mm per 1 m length. This allowed the party to 25% of the pipes with the curvature and torsion of more than 3 mm but not exceeding 4 mm.


(Changed edition, Rev. N 2).