Flange marking and marking examples
1. National standard marking: Flanges should be marked according to the nominal diameter, nominal pressure, sealing surface form code, steel pipe series code (for metric pipes, the code is "Series 2", for imperial pipes, it is not marked), and standard number.
Marking example: A convex welded Steel Pipe Flange with a nominal diameter of 80mm and a nominal pressure of 4.0MPa (25bar) (equipped with metric pipes)
Flange DN80-PN40 M (Series 2) GB/T9115.2-2000, with a nominal diameter of 100mm and a nominal pressure of 5.0MPa (25bar), is a flat welded Steel Pipe Flange with a protruding face and neck (equipped with imperial pipes) flange DN100-PN50 RF GB/T9116.1-2000.
2. Mechanical Department Standard Marking:
Marking example: A protruding flat welded Steel Pipe Flange with a nominal diameter of 500mm and a nominal pressure of 1.6MPa, series 2
Flange 500-16 JB/T81-94
Concave butt welded Steel Pipe Flange with nominal diameter of 300mm and nominal pressure of 6.4MPa, series 1
Flange 300-64B (Series 1) JB/T82.2-94
(Note: The default outer diameter of the pipe in the mechanical department standard is series 2, and the classification of butt welded flanges is: A-type convex surface, B-type concave surface, C-type tenon surface, D-type groove surface)
3. Standard marking of the Ministry of Chemical Industry: Flanges should be marked according to the following regulations (this marking method is recommended)
a、Standard number: All types of Pipe Flanges are uniformly marked with the standard number of this standard: HG20592.
b、 The flange type code shall be in accordance with the provisions of Table 5.0.1.
When using tapered pipe threads according to GB/T7306 for Threaded Flanges, mark them as "Th (Rc)" or "Th (Rp)";
When the threaded flange adopts the taper pipe thread specified in GB/T12716, it is marked as "Th (NPT)";
If the thread code is not marked on the threaded flange, it is Rp (GB/T7306.1).
c、 Flange nominal diameter DN (mm) and applicable steel pipe outer diameter series:
Integral flange, flange cover, lining flange cover, threaded flange, applicable markings for steel pipe outer diameter series can be omitted;
Suitable for flanges of international universal series steel pipes (commonly known as imperial pipes), marked with "DN (A)";
Suitable for flanges of domestically used series steel pipes (commonly known as metric pipes), marked as "DN (B)".
d、 The nominal pressure of the flange is PN, MPa.
e、 The form code of the sealing surface shall be in accordance with the provisions of Table 6.0.1. If the protruding flange has a car made embossed water line, it shall be marked as "RF (A)".
f、 The wall thickness of the steel pipe should be provided by the user.
Neck welding flanges and welding ring loose flanges should be marked with the wall thickness of the steel pipe.
g、 Material grade.
h、 other. Adopt requirements or additional requirements that are inconsistent with the provisions of this standard series, such as surface roughness of sealing surfaces.
Example of Marking:
A protruding plate flat welded steel pipe flange with a nominal diameter of 1200mm and a nominal pressure of 0.6MPa, equipped with metric pipes, made of Q235A material
HG20592 flange PL1200 (B) -0.6 RF Q235A
A steel pipe flange with a nominal diameter of 300mm, a nominal pressure of 2.5MPa, and a convex surface and neck flat welding steel pipe flange for use with imperial pipes. The material is 20 steel
HG20592 flange SO300 (A) -2.5 M 20
The nominal diameter is 150mm, the nominal pressure is 16.0MPa, and it is equipped with a flange made of welded steel pipe with a neck on the ring connecting face of the British system pipe. The material is 16Mn, and the wall thickness of the steel pipe is 10mm
HG20592 flange WN150 (A) -16.0 RJ S=10mm 16Mn
The nominal diameter is 200mm, the nominal pressure is 1.0MPa, and the protruding face of the metric pipe is equipped with a welded ring loose sleeve steel pipe flange. The material is flange 20, welded ring 316, and the steel pipe wall thickness is 4mm
HG20592 flange PJ/SE200 (B) -1.0 RF S=4mm 20/316