Issues with equipment manhole covers
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For a certain air storage tank, the drawings require penetrant testing to be carried out on dissimilar steels; the manhole covers for the equipment are to be made of carbon steel with an anti-corrosion coating. I would like to ask for everyone’s advice. Is penetrant testing still required here?
We only handle airtightness testing; we didn’t do penetration testing before. Now the person stationed at the factory has put forward this requirement – how should I persuade him?
Are you adding a lining plate inside the manhole cover, with fillet welds at the edges and plug welding in the middle? It shouldn’t be a problem to do a PT on the weld, right?:lol
Doing more is definitely good, but penetration isn’t necessary here.
Although the weld joint between the flange and the gasket is a dissimilar steel joint, it is not under pressure; therefore, surface inspection is not necessary. The key is to ensure airtightness and prevent any leaks.
Firstly, for welded joints of different steel grades, GB150 sets specific requirements. Secondly, if the equipment is under negative pressure, it’s necessary to check whether the lining plate can withstand such pressure: lol
If there is a contractual relationship, then go ahead and do it. It’s not hard either.