I have a few questions regarding flanges that I need to ask

@boyirensheng

First, one needs to go to elementary school to study Chinese a bit. Add punctuation to the original text, and divide it into 3 questions. Then go and download to learn about the GB/T9112~9124 standards. 1. What is the manufacturing process for the GB9113 integral steel flange? Answer: Casting. 2. If it is to be welded to a pipe, what should be done if the diameter of the flange differs from that of the pipe? Answer: GB/T9113 is not designed for welding to pipes; it is an integral flange. 3. Where can I buy flanges that are suitable for welding pipes and meet the GB9113 standard? Answer: As for question 2, GB/T9119 is generally used for low-pressure applications, while GB/T9115 is used for high-pressure applications.

Thank you for your reply. I understand. But what if the product requires flanges made in accordance with GB9113 standards for welding? Welding high-diameter flanges?

There is a product requirement that the flange must comply with GB9113, and it also needs to be welded to the steel pipe – such a requirement isn’t correct, right? Should flanges according to GB9119 be used for welding to the pipes, right?

What are the general standards for steel pipes, experts?

This post was last edited by Yimi on 2016-5-24 at 16:06. Disagree. First of all, your punctuation marks also seem a bit strange; I’m not sure if you’ve distinguished between full-width and half-width characters. 1. Cast flanges are available. However, clause 3.2 of GB/T9124 \"Technical Requirements for Steel Pipe Flanges\" specifies that the materials for flanges under this series of standards are forgings, castings, and sheets. In fact, due to quality issues, cast flanges are not commonly used in most petrochemical plants. Even for forged flanges, there are requirements regarding different materials and pressure levels, as well as specific grades and technical specifications, as detailed in the relevant standards. 2. The vast majority of flanges are designed for welding to pipes and pipe fittings, and integral flanges are no exception. I’ve never seen two flanges paired together with bolts and placed separately for use. 3. GB/T9119 \"Plate-type butt-welded steel pipe flanges\" and GB/T9115 \"Seam-welded steel pipe flanges\"; it’s not clear what their relationship is with GB/T9113. There are no restrictions on the standards for pipes welded to flanges (note: it refers to size standards); the main distinction lies in the outer diameter series (there are two commonly used series: metric and imperial), with the wall thickness also specified. The correct order is to know the outer diameter and wall thickness of the pipe, and specify them in the purchase documents for the flanges, rather than buying the flanges first and then trying to match them to the pipe. Of course, if you’ve bought the flanges but don’t have the pipes yet, it’s not impossible to purchase the pipes according to the dimensions required for connecting them to the flanges. Finally, I would like to say to the original poster that the flanges and pipes that arrived had inconsistent outer diameters and wall thicknesses. There are two options: buy them again (either the flanges or the pipes), but this is rarely done ； Machine a transition short section.

I would like to ask what the manufacturing process is for the GB9113 full-steel flanges. The common manufacturing methods include forging and casting; however, this type of flange is not very commonly used. If it needs to be welded to pipes, what should be done if the diameter of the flange differs from that of the pipe? The diameters must match; otherwise, the flange cannot be used. Keep in mind that pipes represent the main component, while flanges, valves, elbows, tees, and other pipe fittings are all designed to work in conjunction with pipes, so they generally change along with the pipes. Where can I buy flanges that are suitable for welding pipes and meet the GB9113 standards? Just list the types of pipes. For pressure pipes, if the pressure is high, GB/T9115-2010 should be used; for medium-pressure pipes, both GB/T9115-2010 and GB/T9116-2010 can be chosen; for low-pressure pipes, GB/T9119-2010 is appropriate