Pipe Flange, MS Seamless Flange, Carbon Steel Flange, Stainless Steel Flange, Flange Fittings, Pipe Flange Gasket
Flanges are used to connect pipes with each other, to valves, to fittings, and to specialty items such as strainers and pressure vessels. A cover plate can be connected to create a "blind flange". Flanges are joined by bolting, and sealing is often completed with the use of gaskets or other methods.
Flange connection is to fix two pipes, pipe fittings or equipment on a flange plate, add flange pads between the two flange plates, and fasten them together with bolts to complete the connection. Some pipe fittings and equipment already come with flanges, which are also flange connections. Flange connection is an important connection method in pipeline construction. Flange connection is easy to use and can withstand large pressure.
Flange Standard |
ASTM A182, ASTM A105, ASTM A234 WPB, A860,A694,AWWA C207 |
Flange Material | Carbon Steel Flange, Alloy Steel Flange, Stainless Steel Flange |
Flange Sizes |
1/2”-60” NPS (DN15-DN3000), SCH10,STD,SCH40,SCH60,XS,SCH80,SCH120,SCH160,XXS |
Flange Class |
Class150-Class2500 |
Flange Facing |
RF/ FM/ M/ T G/ RF / FF / RTJ |
Flange Types |
Socket Weld Flange, Slip On Flange, Blind,Screwed Flange, Ring Joint Flange, Weld Neck Flange, Long Weld Neck Flange |
Common flanges
Special flanges
Blind Flanges
Blind Flanges are round plates which have all relevant boltholes but lack a center hole and thus are used to close off the ends of a piping system or a pressure vessel opening.
Forged Steel Blind Flanges conform to ASTM A105 while Stainless Steel Flanges conform to ASTM A182.
Stocked in sizes from 1/2" to 24".
Available both with a flat face and a raised face.
Flanges of Class 150#, 300#, 600#, 900#, and 1500# are stocked.
Available in Carbon Steel as well as Stainless in grades 304L and 316L (L=low carbon).
Carbon Steel Flanges are available in both domestic and less expensive Imported versions. All Stainless Blind Flanges that we stock are imported.
Lap Joint Flanges
Lap Joint Flanges slide directly over a pipe and are used with Stub Ends. Typically, a pipe is welded to the Stub End leaving the Lap Joint Flange to rotate freely around the stub end, simplifying bolt hole alignment.
Lap Joint Flanges are forged steel and conform to ASTM A105.
Stocked in sizes from 1.50" to 20".
Forged Steel Lap Joint Flanges are available in both domestic and less expensive Imported versions.
Stub Ends are sold separately.
Slip On Flanges
Slip On Flanges are manufactured with an inside diameter that is slightly larger than the pipe's outside diameter and are connected to the pipe via fillet weld at the top and bottom of the flange.
Stocked in sizes from 1/2" to 24", depending on the material.
Aluminum Flanges conform to ASM 6061 T6.
Carbon Steel Slip On Flanges conform to ASTM A105.
Stainless Steel Slip On Flanges conform to ASTM A182. Both 304L and 316L available.
Available with both a Raised Face and a Flat Face.
Socket Weld Flanges
Socket Weld Flanges are often used on smaller sizes of high pressure pipe and are attached to that pipe by inserting the pipe into the socket end and applying fillet weld around the top. This results in a smooth bore with excellent flow characteristics.
Stocked in sizes from 1/2" to 6".
Carbon Steel Socket Weld Flanges conform to ASTM A105.
Stainless Flanges conform to ASTM A182. Both 304L and 316L available.
Classes available range from 150# to 1500#.
Threaded Flanges
Threaded Flanges have a bore with tapered threads and connect to pipes that have external threads. The primary benefit of Threaded Flanges is that no welding is required to attach them.
Stocked in sizes from 1/2" to 8".
Carbon Steel Threaded Flanges conform to ASTM A105.
Stainless Steel Threaded Flanges conform to ASTM A182. Both 304L and 316L available.
Classes available range from 150# to 1500#.
Weld Neck Flanges
Weld Neck Flanges are attached by welding a pipe to the neck of the flange, transferring stress from the flange itself to the connected pipe. They are often used in high pressure applications.
Stocked in sizes from 1/2" to 24".
Aluminum Weld Neck Flanges conform to ASM 6061 T6.
Carbon Steel Weld Neck Flanges conform to ASTM A105.
High Yield Weld Neck Flanges conform to ASTM A694 F52.
Stainless Steel Weld Neck Flanges conform to ASTM A182. Both 304L and 316L available.
Classes available range from 150# to 1500#.
CLASS 150 According to ASTM A/SA-105; ANSI B16.5 |
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Nominal Pipe Size |
Outside Diam. of Flange (O) |
Thick. of Flange (C) |
Diam. of Raised Face (R) |
Diam. of Hub at Base (X) |
Length thru Hub (Y) |
Min. Thread Length (T) |
Min. Counter Bore (Q) |
No. of Holes |
Diam. of Holes |
Diam. of Bolts |
Diam. of Bolt Circle |
Approx. Weight (in Pounds) |
½ | 3.5 | 0.44 | 1.38 | 1.19 | 0.62 | 0.62 | | 4 | 0.62 | 0.5 | 2.38 | 1 |
¾ | 3.88 | 0.5 | 1.69 | 1.5 | 0.62 | 0.62 | | 4 | 0.62 | 0.5 | 2.75 | 2 |
1 | 4.25 | 0.56 | 2 | 1.94 | 0.69 | 0.69 | | 4 | 0.62 | 0.5 | 3.12 | 2 |
1 ¼ | 4.62 | 0.62 | 2.5 | 2.31 | 0.81 | 0.81 | | 4 | 0.62 | 0.5 | 3.5 | 3 |
1 ½ | 5 | 0.69 | 2.88 | 2.56 | 0.88 | 0.88 | | 4 | 0.62 | 0.5 | 3.88 | 3 |
2 | 6 | 0.75 | 3.62 | 3.06 | 1 | 1 | | 4 | 0.75 | 0.62 | 4.75 | 5 |
2 ½ | 7 | 0.88 | 4.12 | 3.56 | 1.12 | 1.12 | | 4 | 0.75 | 0.62 | 5.5 | 7 |
3 | 7.5 | 0.94 | 5 | 4.25 | 1.19 | 1.19 | | 4 | 0.75 | 0.62 | 6 | 8 |
3 ½ | 8.5 | 0.94 | 5.5 | 4.81 | 1.25 | 1.25 | | 8 | 0.75 | 0.62 | 7 | 11 |
4 | 9 | 0.94 | 6.19 | 5.31 | 1.31 | 1.31 | | 8 | 0.75 | 0.62 | 7.5 | 13 |
5 | 10 | 0.94 | 7.31 | 6.44 | 1.44 | 1.44 | | 8 | 0.88 | 0.75 | 8.5 | 15 |
6 | 11 | 1 | 8.5 | 7.56 | 1.56 | 1.56 | | 8 | 0.88 | 0.75 | 9.5 | 19 |
8 | 13.5 | 1.12 | 10.62 | 9.69 | 1.75 | 1.75 | | 8 | 0.88 | 0.75 | 11.75 | 30 |
10 | 16 | 1.19 | 12.75 | 12 | 1.94 | 1.94 | | 12 | 1 | 0.88 | 14.25 | 43 |
12 | 19 | 1.25 | 15 | 14.38 | 2.19 | 2.19 | | 12 | 1 | 0.88 | 17 | 64 |
14 | 21 | 1.38 | 16.25 | 15.75 | 2.25 | 2.25 | | 12 | 1.12 | 1 | 18.75 | 90 |
16 | 23.5 | 1.44 | 18.5 | 18 | 2.5 | 2.5 | | 16 | 1.12 | 1 | 21.25 | 98 |
18 | 25 | 1.56 | 21 | 19.88 | 2.69 | 2.69 | | 16 | 1.25 | 1.13 | 22.75 | 130 |
20 | 27.5 | 1.69 | 23 | 22 | 2.88 | 2.88 | | 20 | 1.25 | 1.12 | 25 | 165 |
24 | 32 | 1.88 | 27.25 | 26.12 | 3.25 | 3.25 | | 20 | 1.38 | 1.25 | 29.5 | 220 |
CLASS 300 According to ASTM A/SA-105; ANSI B16.5 |
||||||||||||
Nominal Pipe Size |
Outside Diam. of Flange (O) |
Thick. of Flange (C) |
Diam. of Raised Face (R) |
Diam. of Hub at Base (X) |
Length thru Hub (Y) |
Min. Thread Length (T) |
Min. Counter Bore (Q) |
No. of Holes |
Diam. of Holes |
Diam. of Bolts |
Diam. of Bolt Circle |
Approx. Weight (in Pounds) |
1/2 | 3.75 | 0.56 | 1.38 | 1.5 | 0.88 | 0.62 | 0.93 | 4 | 0.62 | 0.5 | 2.62 | 2 |
3/4 | 4.62 | 0.62 | 1.69 | 1.88 | 1 | 0.62 | 1.14 | 4 | 0.75 | 0.62 | 3.25 | 3 |
1 | 4.88 | 0.69 | 2 | 2.12 | 1.06 | 0.69 | 1.41 | 4 | 0.75 | 0.62 | 3.5 | 3 |
1 1/4 | 5.25 | 0.75 | 2.5 | 2.5 | 1.06 | 0.81 | 1.75 | 4 | 0.75 | 0.62 | 3.88 | 4 |
1 1/2 | 6.12 | 0.81 | 2.88 | 2.75 | 1.19 | 0.88 | 1.99 | 4 | 0.88 | 0.75 | 4.5 | 6 |
2 | 6.5 | 0.88 | 3.62 | 3.31 | 1.31 | 1.12 | 2.5 | 8 | 0.75 | 0.62 | 5 | 7 |
2 1/2 | 7.5 | 1 | 4.12 | 3.94 | 1.5 | 1.25 | 3 | 8 | 0.88 | 0.75 | 5.88 | 10 |
3 | 8.25 | 1.12 | 5 | 4.62 | 1.69 | 1.25 | 3.63 | 8 | 0.88 | 0.75 | 6.62 | 13 |
3 1/2 | 9 | 1.19 | 5.5 | 5.25 | 1.75 | 1.44 | 4.13 | 8 | 0.88 | 0.75 | 7.25 | 17 |
4 | 10 | 1.25 | 6.19 | 5.75 | 1.88 | 1.44 | 4.63 | 8 | 0.88 | 0.75 | 7.88 | 22 |
5 | 11 | 1.38 | 7.31 | 7 | 2 | 1.69 | 5.69 | 8 | 0.88 | 0.75 | 9.25 | 28 |
6 | 12.5 | 1.44 | 8.5 | 8.12 | 2.06 | 1.81 | 6.75 | 12 | 0.88 | 0.75 | 10.62 | 39 |
8 | 15 | 1.62 | 10.62 | 10.25 | 2.44 | 2 | 8.75 | 12 | 1 | 0.88 | 13 | 58 |
10 | 17.5 | 1.88 | 12.75 | 12.62 | 2.62 | 2.19 | 10.88 | 16 | 1.12 | 1 | 15.25 | 81 |
12 | 20.5 | 2 | 15 | 14.75 | 2.88 | 2.38 | 12.94 | 16 | 1.25 | 1.12 | 17.75 | 115 |
14 | 23 | 2.12 | 16.25 | 16.75 | 3 | 2.5 | 14.19 | 20 | 1.25 | 1.12 | 20.25 | 165 |
16 | 25.5 | 2.25 | 18.5 | 19 | 3.25 | 2.69 | 16.19 | 20 | 1.38 | 1.25 | 22.5 | 190 |
18 | 28 | 2.38 | 21 | 21 | 3.5 | 2.75 | 18.19 | 24 | 1.38 | 1.25 | 24.75 | 250 |
20 | 30.5 | 2.5 | 23 | 23.12 | 3.75 | 2.88 | 20.19 | 24 | 1.38 | 1.25 | 27 | 315 |
24 | 36 | 2.75 | 27.25 | 27.62 | 4.19 | 3.25 | 24.19 | 24 | 1.62 | 1.5 | 32 | 475 |
CLASS 600 According to ASTM A/SA-105; ANSI B16.5 |
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Nominal Pipe Size |
Outside Diam. of Flange (O) |
Thick. of Flange (C) |
Diam. of Raised Face (R) |
Diam. of Hub at Base (X) |
Length thru Hub (Y) |
Min. Thread Length (T) |
Min. Counter Bore (Q) |
No. of Holes |
Diam. of Holes |
Diam. of Bolts |
Diam. of Bolt Circle |
Approx. Weight (in Pounds) |
1/2 | 3.75 | 0.56 | 1.38 | 1.5 | 0.88 | 0.62 | 0.93 | 4 | 0.62 | 0.5 | 2.62 | 2 |
3/4 | 4.62 | 0.62 | 1.69 | 1.88 | 1 | 0.62 | 1.14 | 4 | 0.75 | 0.62 | 3.25 | 3 |
1 | 4.88 | 0.69 | 2 | 2.12 | 1.06 | 0.69 | 1.41 | 4 | 0.75 | 0.62 | 3.5 | 4 |
1 1/4 | 5.25 | 0.81 | 2.5 | 2.5 | 1.12 | 0.81 | 1.75 | 4 | 0.75 | 0.62 | 3.88 | 5 |
1 1/2 | 6.12 | 0.88 | 2.88 | 2.75 | 1.25 | 0.88 | 1.99 | 4 | 0.88 | 0.75 | 4.5 | 7 |
2 | 6.5 | 1 | 3.62 | 3.31 | 1.44 | 1.12 | 2.5 | 8 | 0.75 | 0.62 | 5 | 9 |
2 1/2 | 7.5 | 1.12 | 4.12 | 3.94 | 1.62 | 1.25 | 3 | 8 | 0.88 | 0.75 | 5.88 | 13 |
3 | 8.25 | 1.25 | 5 | 4.62 | 1.81 | 1.38 | 3.63 | 8 | 0.88 | 0.75 | 6.62 | 16 |
3 1/2 | 9 | 1.38 | 5.5 | 5.25 | 1.94 | 1.56 | 4.13 | 8 | 1 | 0.88 | 7.25 | 21 |
4 | 10.75 | 1.5 | 6.19 | 6 | 2.12 | 1.62 | 4.63 | 8 | 1 | 0.88 | 8.5 | 37 |
5 | 13 | 1.75 | 7.31 | 7.44 | 2.38 | 1.88 | 5.69 | 8 | 1.12 | 1 | 10.5 | 63 |
6 | 14 | 1.88 | 8.5 | 8.75 | 2.62 | 2 | 6.75 | 12 | 1.12 | 1 | 11.5 | 80 |
8 | 16.5 | 2.19 | 10.62 | 10.75 | 3 | 2.25 | 8.75 | 12 | 1.25 | 1.12 | 13.75 | 115 |
10 | 20 | 2.5 | 12.75 | 13.5 | 3.38 | 2.56 | 10.88 | 16 | 1.38 | 1.25 | 17 | 170 |
12 | 22 | 2.62 | 15 | 15.75 | 3.62 | 2.75 | 12.94 | 20 | 1.38 | 1.25 | 19.25 | 200 |
14 | 23.75 | 2.75 | 16.25 | 17 | 3.69 | 2.88 | 14.19 | 20 | 1.5 | 1.38 | 20.75 | 230 |
16 | 27 | 3 | 18.5 | 19.5 | 4.19 | 3.06 | 16.19 | 20 | 1.62 | 1.5 | 23.75 | 330 |
18 | 29.25 | 3.25 | 21 | 21.5 | 4.62 | 3.12 | 18.19 | 20 | 1.75 | 1.63 | 25.75 | 400 |
20 | 32 | 3.5 | 23 | 24 | 5 | 3.25 | 20.19 | 24 | 1.75 | 1.62 | 28.5 | 510 |
24 | 37 | 4 | 27.25 | 28.25 | 5.5 | 3.62 | 24.19 | 24 | 2 | 1.88 | 33 | 730 |
CLASS 900According to ASTM A/SA-105; ANSI B16.5 |
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Nominal Pipe Size |
Outside Diam. of Flange (O) |
Thick. of Flange (C) |
Diam. of Raised Face (R) |
Diam. of Hub at Base (X) |
Length thru Hub (Y) |
Min. Thread Length (T) |
Min. Counter Bore (Q) |
No. of Holes |
Diam. of Holes |
Diam. of Bolts |
Diam. of Bolt Circle |
Approx. Weight (in Pounds) |
1/2 | 4.75 | 0.88 | 1.38 | 1.5 | 1.25 | 0.88 | 0.93 | 4 | 0.88 | 0.75 | 3.25 | 4 |
3/4 | 5.12 | 1 | 1.69 | 1.75 | 1.38 | 1 | 1.14 | 4 | 0.88 | 0.75 | 3.5 | 5 |
1 | 5.88 | 1.12 | 2 | 2.06 | 1.62 | 1.12 | 1.41 | 4 | 1 | 0.88 | 4 | 8 |
1 1/4 | 6.25 | 1.12 | 2.5 | 2.5 | 1.62 | 1.19 | 1.75 | 4 | 1 | 0.88 | 4.38 | 9 |
1 1/2 | 7 | 1.25 | 2.88 | 2.75 | 1.75 | 1.25 | 1.99 | 4 | 1.12 | 1 | 4.88 | 12 |
2 | 8.5 | 1.5 | 3.62 | 4.12 | 2.25 | 1.5 | 2.5 | 8 | 1 | 0.88 | 6.5 | 25 |
2 1/2 | 9.62 | 1.62 | 4.12 | 4.88 | 2.5 | 1.88 | 3 | 8 | 1.12 | 1 | 7.5 | 36 |
3 | 9.5 | 1.5 | 5 | 5 | 2.12 | 1.62 | 3.63 | 8 | 1 | 0.88 | 7.5 | 26 |
4 | 11.5 | 1.75 | 6.19 | 6.25 | 2.75 | 1.88 | 4.63 | 8 | 1.25 | 1.12 | 9.25 | 53 |
5 | 13.75 | 2 | 7.31 | 7.5 | 3.12 | 2.12 | 5.69 | 8 | 1.38 | 1.25 | 11 | 83 |
6 | 15 | 2.19 | 8.5 | 9.25 | 3.38 | 2.25 | 6.75 | 12 | 1.25 | 1.12 | 12.5 | 110 |
8 | 18.5 | 2.5 | 10.62 | 11.75 | 4.00 | 2.50 | 8.75 | 12 | 1.5 | 1.38 | 15.5 | 170 |
10 | 21.5 | 2.75 | 12.75 | 14.5 | 4.25 | 2.81 | 10.88 | 16 | 1.5 | 1.38 | 18.5 | 245 |
12 | 24 | 3.12 | 15 | 16.5 | 4.62 | 3 | 12.94 | 20 | 1.5 | 1.38 | 21 | 325 |
14 | 25.25 | 3.38 | 16.25 | 17.75 | 5.12 | 3.25 | 14.19 | 20 | 1.62 | 1.5 | 22 | 400 |
16 | 27.75 | 3.5 | 18.5 | 20 | 5.25 | 3.38 | 16.19 | 20 | 1.75 | 1.63 | 24.25 | 425 |
18 | 31 | 4 | 21 | 22.25 | 6 | 3.5 | 18.19 | 20 | 2 | 1.88 | 27 | 600 |
20 | 33.75 | 4.25 | 23 | 24.5 | 6.25 | 3.62 | 20.19 | 20 | 2.12 | 2 | 29.5 | 730 |
24 | 41 | 5.5 | 27.25 | 29.5 | 8 | 4 | 24.19 | 20 | 2.62 | 2.5 | 35.5 | 1400 |
CLASS 1500 According to ASTM A/SA-105; ANSI B16.5 |
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Nominal Pipe Size |
Outside Diam. of Flange (O) |
Thick. of Flange (C) |
Diam. of Raised Face (R) |
Diam. of Hub at Base (X) |
Length thru Hub (Y) |
Min. Thread Length (T) |
Min. Counter Bore (Q) |
No. of Holes |
Diam. of Holes |
Diam. of Bolts |
Diam. of Bolt Circle |
Approx. Weight (in Pounds) |
1/2 | 4.75 | 0.88 | 1.38 | 1.5 | 1.25 | 0.88 | 0.93 | 4 | 0.88 | 0.75 | 3.25 | 4 |
3/4 | 5.12 | 1 | 1.69 | 1.75 | 1.38 | 1 | 1.14 | 4 | 0.88 | 0.75 | 3.5 | 5 |
1 | 5.88 | 1.12 | 2 | 2.06 | 1.62 | 1.12 | 1.41 | 4 | 1 | 0.88 | 4 | 8 |
1 1/4 | 6.25 | 1.12 | 2.5 | 2.5 | 1.62 | 1.19 | 1.75 | 4 | 1 | 0.88 | 4.38 | 9 |
1 1/2 | 7 | 1.25 | 2.88 | 2.75 | 1.75 | 1.25 | 1.99 | 4 | 1.12 | 1 | 4.88 | 12 |
2 | 8.5 | 1.5 | 3.62 | 4.12 | 2.25 | 1.5 | 2.5 | 8 | 1 | 0.88 | 6.5 | 25 |
2 1/2 | 9.62 | 1.62 | 4.12 | 4.88 | 2.5 | 1.88 | 3 | 8 | 1.12 | 1 | 7.5 | 36 |
Thailand A182-F36 DN100 x CL2500 500 Nos |
UAE SS 304 size500,PN16 152 Nos |
UAE ASTM A105 18" Class 300# 1562 Nos |
Nigeria |
Columbia |
Mexico ASTM A105 1/2"- 150 # -RF 500 Nos |
Mexico ASTM A182 F53 6" sch10s 1500 Nos |
Serbia ASTM A182 Gr.F304/304L 2" RTJ Face 1500 Lbs 3000 Nos |