1998GOST 6942-1998 Cast iron waste pipes and fitings. Specifications
1980GOST 6942.6-1980 Cast iron waste pipes and fittings. Reducers. Construction and dimensions
0000 GOST 6942.7-1969
GOST 6942.6-1980 Cast iron waste pipes and fittings. Reducers. Construction and dimensions was changed to GOST 6942-1998 Cast iron waste pipes and fitings. Specifications.