Flange Thickness - Why so Thick???
Please I need your help!!!!!
I am designing a fixing that must tie in with standard Raised Face Flanges taking a pressure of 16Barg. The fixing has a flange either side and a section of pipe welded between. (a spacer for the want of a better word). The flanges I am designing are to suit BSEN 1092-1 standard DN flanges. The flanges I am designing are acting as a fixing plate due to the pipe between. The std sch 40 pipe will be seeing the pressure, the flanges are merely a locating and fixing plate. I have people telling me they need to be the same thickness as std flanges, yet others are telling me I can reduce the thickness considerably.
Can anyone tell me how to calculate the thickness of flanges for the above pressure. I am concentrating on DN300NP16 at the moment but want to work out up to DN2000NP16.
Any help is appreciated.
Hi Tony,
Pressure works in all directions. The flanges are designed to prevent moving away from each other longitudinally. Reduce flange thickness at your peril. If they could technically be thinner and still meet the specs, they would be made thinner.
Just one old fart's opinion.
What benefit will reducing the flange thickness have?
Without analysis I think the question should be "What loss of benefit will reducing the flange thickness have?"Originally Posted by JohnRUFC
That "Spacer" you refer to is usually the component that does the sealing between the flanges (check me). The flanges are generally a stronger material in both hardness and deflection under compression. The spacer/seal deforms (compresses) under load from the flanges being bolted together to facilitate the fluid seal. The flange surface will have flatness imperfections and this needs to be compensated for.
Also, the flange thickness is helpful in heat energy dissipation during welding to prevent distortions.
If you have a proven thinner flange design – use it, otherwise I would just stick with the industry standard design.
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