【Y2025】Understand the meaning of markings on flanges at a glance
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This post was last edited by zhoudingshengs on 2025-1-12 at 11:32. The video is about the meaning of the marking characters on flanges.
The outer diameters of steel pipes covered by chemical industry standards include two series: A and B. Series A is the internationally standard series (commonly known as imperial pipes), while series B is the series used in China (commonly known as metric pipes).
Keep in mind: standards starting with HG are chemical industry standards, those starting with GB are national standards, those starting with JB are mechanical industry standards, those starting with SH are petrochemical industry standards, and those starting with CB are marine standards.
As for foreign standards, those starting with ANSI are American standards, those starting with DIN are German standards, those starting with EN are European standards, and those starting with JIS are Japanese standards……
“\"PL\" refers to the flange type code – plate flat face flange. In addition, there are also: SO (sleeved flat face flange), WN (sleeved weld neck flange), IF (integral flange), SW (socket weld flange), Th (threaded flange), BL (flange cover), and PJ/SE (weld ring loose flange).
The current flange standards in China include **general standards, chemical industry standards, mechanical standards, petrochemical standards, etc. There are so many of these standards that it can be confusing, and each standard sets requirements regarding the markings on flanges. Here, the chemical industry standard (PN series) is taken as an example.
In accordance with current chemical industry standards, for integral flanges, flange covers, lined flange covers, and threaded flanges, the marking of the outer diameter series of the steel pipe can be omitted. For flanges applicable to steel pipes in Series A of this standard, the marking indicating the outer diameter series of the steel pipe can be omitted ； Flanges for steel pipes of Series B conforming to this standard are marked as “DNXXX(B)”.
“\"PL\" refers to the flange type code – plate flat face flange. In addition, there are also: SO (sleeved flat face flange), WN (sleeved weld neck flange), IF (integral flange), SW (socket weld flange), Th (threaded flange), BL (flange cover), and PJ/SE (weld ring loose flange). For example, “100-16” after “PL” also refers to the nominal size and nominal pressure of the pipe applicable.