Washers for Flanged Connections with Medium Temperature from 0 to 650°C

Backing washers for flanged connections of steam and gas turbines, steam boilers, pipelines and fittings, valves, instruments, equipment and tanks with a medium temperature from 0 to 650 °C.

This standard does not apply to flanged connections of facilities under the jurisdiction of Gosgortekhnadzor of the USSR with nominal pressure P less than 4 MPa (40 kgf/cm²).

Washer dimensions shall conform to those shown in the drawing and table.

Washers for Flanged Connections with Medium Temperature from 0 to 650°C. Types and Main Dimensions	GOST 9065-75* Supersedes GOST 9065-69

Nominal stud thread diameter d	10	12	16	20	(22)	24	(27)	30	36	42	48
Internal diameter d₁ (tolerance per H12)	11	13	17	21	23	25	28	31	37	43	50
Outside diameter d₂ (tolerance per h14)	18	24	30	37	34	44	50	56	66	78	90
Washer thickness s (tolerance per h14)	2.5			4			5		6		10
Chamfer c	0.5			1.0			1.6				2.0
Permissible offset of hole axis	0.5	0.6				0.7

Continued, mm

Nominal stud thread diameter d	(52)	56	(60)	64	(68)	72	(76)	80	90	100	110	(120)	125	140	160
Internal diameter d₁ (tolerance per H12)	54	58	62	66	70	74	78	82	92	102	112	122	127	142	162
Outside diameter d₂ (tolerance per h14)	95	100	110	115	120	126	132	138	155	174	190	208	215	242	276
Washer thickness s (tolerance per h14)	10						12			14				16
Chamfer c	2.0						3.0				4.0
Permissible offset of hole axis	0.8						0.9				1.0			1.2

Notes:

1. Washers with dimensions shown in brackets should be avoided where possible.

2. For washers manufactured by stamping, the limit deviations are h24 for the internal diameter, h14 for the outside diameter, and per the standards for the raw material for washer thickness.

3. Washers may be manufactured without a chamfer or with edges rounded to a radius equal to dimension c.

Example of a washer designation for a stud with thread diameter M48, made of grade 20 steel, category III, quality group 4, with coating 0.2, thickness 9 µm:

Washer 48.20.III.4.029 GOST 9065-75

Washer mass is given in reference Appendix 1.

Technical requirements — per GOST 20700-75.

Nominal stud thread diameter, mm	Theoretical mass of 1000 pcs. washers, » kg	Nominal diameter (stud thread size), mm	Theoretical mass of 1000 pcs. washers, » kg
10	4.20	60	508.57
12	6.27	64	546.35
16	9.41	68	585.20
20	22.87	72	640.64
22	24.44	76	838.25
24	32.30	in	910.69
27	52.85	90	1177.18
30	66.99	100	1713.76
36	110.40	110	2031.47
42	156.52	120	2447.49
48	344.96	125	2595.48
52	376.31	140	3784.70
56	408.79	160	4921.30