Is it necessary to recalculate the dimensions of the boiler manholes?
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In the NB/T47040 standard for boiler manholes, the dimensions of the long axis a and short axis b of the elliptical manholes have changed; is it necessary to recalculate them? If calculation is needed, what kind of calculation should be done?
Calculation for manhole ring reinforcement, calculation for manhole cover thickness.
Try to use manholes of standard sizes
We only calculate its cylinder, and the rest is selected based on the standard rated pressure. Based on the maximum major axis, if reinforcement is not sufficient, a reinforcing ring must be added. The length of the cylinder sections for the manhole on the main boiler should be made from the standard material used for boilers, as there are some differences compared to materials used in pressure vessels.
It’s you who asked a question on Baidu Knows, right? I hope you can confirm who will bear the additional costs resulting from the use of non-standard components!
Thank you all for your enthusiastic responses; I’ve decided to go with the standard version after all.
Our original manhole spools were all welded; I would like to use thick-walled pipes for them, but the specifications aren’t quite suitable – they are larger than what is required by the standards – so I was wondering for your advice. In the end, I gave up.