Flanged ball valves have bolt holes on the top connectors to attach to your matching flanges on a pipe. The graphite packing rings are compressed and held in place with the gland flange, which can be bolted for the stem housing. A slip ball valve is often a specialised variety https://edwinlolhc.robhasawiki.com/11306399/the_best_side_of_stainless_steel_fittings