For HG/T21514~21535-2014 steel manholes, can the outer diameter of A-series fittings be used?
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Our company designed an instrument air storage tank made of carbon steel. This storage tank is a Class I vessel and is regulated by the pressure vessel code. This is the premise. When preparing the purchase plan for the manway flanges, the designers forgot to include the markings for the outer diameter series of the flange connections. It should have been WN500 (B)-16 RF, but it was written as WN500-16 RF. It was only after purchasing the flange that I realized its outer diameter at the neck was Φ508. After reviewing HG/T21514~21535-2014 \"Steel Manholes and Handholes\", we found that although the standards do not specify that B-series flanges must be used for manholes, the pipe connections for various DN500 manhole types specified in these standards all have a diameter of Φ530. I would like to ask the experts here: can A-series fittings really be used with HG/T21514~21535-2014 \"Steel manholes and handholes\"? If it is used, will the Special Inspection Agency raise any objections? Thank you all here!
I don’t think it matters; as long as the calculations are correct, that’s enough. If you’re really worried, use the A-series approach to create drawings for the manholes and include them as part of your blueprint – you just don’t need to specify the standards for those manholes.