GOST 9400-1981 Threaded connecting ends for valves, fittings and pipes with tens - shaped seals for pn20-100 mpa (200-1000 kgf/cm2) dimensions
GOST 22804-1983 history
1983GOST 22804-1983 Assembly units and pipeline parts. Flanged reducing T-branches for Pnom 9,81-98,1 MPa (100-1000 kgf/smsq). Construction and dimensions