Could everyone help determine the cause of the fracture in the valve flange area?
Thread Content
This post was last edited by 9shanghai on 2020-12-9 at 14:13. The medium is gas; it is suspected that ice formed at the flange of the shut-off valve body on the gas pipeline, causing it to break. The shut-off valve is of type HT200 with a diameter of DN200 and a pressure rating of 1.6 MPa. Overall, it seems strange that the flange of the shut-off valve broke – it shouldn’t be that fragile, right?
Pressure, temperature? Are there any other loads or impacts!
Regarding normal-temperature gas in the Xinjiang region, are there any other loads?
It is common for water to freeze at low temperatures and cause the valve body to crack; this is due to the negligence of the designers and has nothing to do with the valve body itself.
Is it that tender? Isn’t that not ice but some other material? Isn’t it the same in that case? Then it’s not an individual phenomenon.
It depends on the material of the valve body; it should be cast iron, otherwise it wouldn’t break. It might be frost cracking.
Diameter: DN200 (nominal diameter) Pressure rating: 1.6 MPa (16 kg) Material: HT200 (gray cast iron)
I think it’s most likely a problem with the quality of the valve casting. Hr200 is a grade of gray cast iron that belongs to ferrous metals; its carbon content ranges from 2% to 43%. For a gray cast iron HT200 sample with an outer diameter of 30 mm, the minimum tensile strength is 200 MPa
Proper prevention of freezing and condensation is not ensured; regions in the north need to pay special attention to such issues, especially in some hard-to-reach areas!