+ö threaded coupling, nipple and threaded valves

[WVW71]

Would it be acceptable to have 1/2" threaded couplings, nipples, and valves installed on a 193' dia, 48' high AST built in 1979, API 650, 6th edition, revision 2, material A-36, and A283-c. The existing coupling/nipples/valves are 1". Table 5-8 of 650 10th edition indicated 3/4" -2". Any help would be greatly appreciated.

WW

 

[fegenbush]

If in doubt, put in a 3/4" or 1" with a reducing bushing. That way you can achieve the desired result of a 1/2" female threaded connection and be in compliance with the original standard of construction.