两条路,Telltole hole 或者 non corrosion。
不过仅仅介质为空气不能充分说明 non corrosion。
Inspection openings may be omitted in vessels covered in (b), ... the Manufacturer’s Data Report shall include one of the following notations under “Remarks”:
(b)
(1) “UG-46(b)” when telltale holes are used in lieu of inspection openings;
...
(4) the statement “for noncorrosive service.” |