Plate Flange | Plain Flange | Hebei Haihao High Pressure Flange & Pipe Fitting Group Co.

Plate Flange,Plain Flange

What is a plate flange(plain flange)?

A plate flange also called plain flange,flat flange,plate slip on flange or ring flange,it is one kind of the slip on flange(without hub).Plate flange looks like a flat,circular disk with inner hole and bolt holes on it,that is welded onto the end of a steel pipe and allows it to be bolted to another pipe.The inner hole of plate flange is a little bigger than the pipe outer diameter.

EN 1092-1 Q235 FF plate flanges

EN 1092-1 Q235 FF plate flanges

Plate flanges are secured to the pipe with a fillet weld at the bottom and the top of flanges with the pipes.The welding method is fillet weld,so the plate flange is not suitable for a high pressure application.Typially used in fuel and water pipelines,the two plate flanges will be bolted together with a gasket between them.

Specifications of plate flange(plain flange):

ANSI/ASME standard:

ANSI/ASME B16.5 (In ANSI/ASME B16.5 standard,there is no plate slip on flange,only hub slip on flange in it,but in different projects the ANSI B16.5 plate flange is used a lot for decrease the cost of the projects.The ANSI/ASME  B16.5 plain flange should have the same dimensions and pcds with the slip on flange,the only difference is without a hub on the flange.)

  • ANSI/ASME B16.5 class 150 plate flange dimensions: ½”-24″
  • ANSI/ASME B16.5 class 300 plate flange dimensions: ½”-24″
  • ANSI/ASME B16.5 class 400 plate flange dimensions: ½”-24″
  • ANSI/ASME B16.5 class 600 plate flange dimensions: ½”-24″
  • ANSI/ASME B16.5 class 900 plate flange dimensions: ½”-24″
  • ANSI/ASME B16.5 class 1500 plate flange dimensions: ½”-2½”
  • AWWA C207

AS standard:

  • AS 2129

BS standard:

  • BS1560
  • BS 4504
  • BS 10 table D,E plate flange dimensions:½”-24″
  • BS 10 table F,H,J,K,R,S,T plate flange dimensions:½”-24″

DIN standard:

  • DIN 2501
  • DIN 2502
  • DIN 2573
  • DIN 2576

EN standard:

  • EN1092-1
  • EN1759-1.

ISO standard:

  • ISO 7005-1

JIS standard:

  • JIS B2220 5K plate slip on flange dimensions: 10-1500A
  • JIS B2220 10K plate slip on flange dimensions: 10-350A

MSS standard:

  • MSS SP-44

UNI standard:

  • UNI 2276
  • UNI 2277
  • UNI 2278
  • UNI 6089
  • UNI 6090

Materials of plate flange:

Haihao Group manufacture plate flanges with various materials,such as carbon steel,stainless steel and alloy steel.

Carbon steel plate flange:

  • ASTM A105 plate flange
  • ASTM A350 LF2 plate flange
  • SS400 plate flange
  • P235GH plate flange
  • P250GH plate flange
  • C22.8 plate flange
  • Q235 plate flange

Stainless steel plate flange:

  • ASTM A182 F304 plate flange
  • ASTM A182 F304L plate flange
  • ASTM A182 F316 plate flange
  • ASTM A182 F316L plate flange
  • ASTM A182 F321 plate flange
  • ASTM A182 F347 plate flange

Alloy steel plate flange:

  • ASTM A694 F42 plate flange
  • ASTM A694 F46 plate flange
  • ASTM A694 F52 plate flange
  • ASTM A694 F56 plate flange
  • ASTM A694 F60 plate flange
  • ASTM A694 F65 plate flange
  • ASTM A694 F70 plate flange
  • ASTM A182 F5 plate flange
  • ASTM A182 F9 plate flange
  • ASTM A182 F11 plate flange
  • ASTM A182 F12 plate flange
  • ASTM A182 F22 plate flange
  • ASTM A182 F91 plate flange

The sealing face of plate flange:

Though the plate flange means the flange is like a flat plate,it could be raised face(RF) sealing face,commonly the plate flange could be RF or FF face,the raised face plain flange is much popular in regular industry systems.

Haihao Group are specialized in the production of forged flanges,our forged flange products as follows:

Integral Flange Long Weld Neck Flange

Long Weld Neck Flange

Orifice flange with weld neck

Orifice flange

Spectacle Blind Flange

Spectacle Blind Flange



Reducing Flange

Reducing Flange

Anchor Flanges

Anchor Flanges

Large Diameter Flange

Large Diameter Flange

SA516 Gr70N Tubesheet


Non-standard Flange

Non-standard Flange

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