Can PJ/RJ flanges replace PJ/SE flanges?

Changes require a change order! Meets the design requirements, with the approval of the designer!

Question 1: The pressure range for PJ/SE is from PN6 to PN40, with a sealing surface type of RF. For PJ/RJ, the pressure range is from PN6 to PN16, also with an RF sealing surface type. MFM and TG types need to be replaced; this requires calculations and adjustments to the design. Question 2: SE components are typically manufactured in one piece, but this depends on the material used – some materials can be formed integrally, such as stainless steel, while others make it difficult to achieve integration, requiring welded connections. Question 3: I’m not very clear about this. Setting aside HG/T20592, the standards for pipe fittings specify different types of flanges, namely long-type and short-type. The value of h for the long-type flange is about 3 times that of HG/T205292, while the value of h for the short-type flange is about 2 times that of HG/T20592. Additionally, the pipe fitting standards specify in the notes that, in order to avoid the influence of flanges on welding, it is sometimes necessary to increase the length of the connecting pipe. The increase in length is determined through negotiation between the manufacturer and the purchaser.

I would like to ask whether the thickness of the flat welding ring in a slip-on flange can differ from that specified in standard 20592. When designing, we often thin out the fillet weld ring because it is too thick

I’m not able to give you an exact answer either; actually, I encounter this situation quite often. Whether it is a butt-welded ring or a flat-welded ring, it is thinned out according to the requirements of the equipment manufacturer.