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Flange

Flange

 Sizes

1/2”-60” NPS (DN15-DN3000) 

Thickness SCH10,STD,SCH40,SCH60,XS, SCH80,SCH120,SCH160,XXS 


Materials:

ASTM A105 – Forged Carbon Steel
ASTM A181 – Forged Carbon Steel for General Purpose
ASTM A182 – Forged Alloy Steel and Stainless Steel
ASTM A350 – Forged Alloy Steel for low temperature services

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 Sizes

1/2”-60” NPS (DN15-DN3000) 

Thickness SCH10,STD,SCH40,SCH60,XS, SCH80,SCH120,SCH160,XXS 


Materials:

ASTM A105 – Forged Carbon Steel
ASTM A181 – Forged Carbon Steel for General Purpose
ASTM A182 – Forged Alloy Steel and Stainless Steel
ASTM A350 – Forged Alloy Steel for low temperature services




Weld Neck Flange


Specification of WN Flanges
Size: DN15-DN2000 (1/2-78 inch)
Surface Treatment: Anti-rust Oil, Transparent/Yellow/Black Anti-rust Paint,Zinc,Hot dipped Galvanized.

Weld Neck Flange Pressure Grade
PN2.5, PN6, PN10, PN16, PN25, PN40, PN63, PN100, PN160, PN250, PN320, PN400
Class 150, Class 300, Class 600, Class 900, Class 1500, Class 2500

Weld Neck Flange Materials
Carbon Steel Flange: ASTM A105, 20#, Q235, 16Mn, ASTM A350 LF1, LF2 CL1/CL2, LF3 CL1/CL2, ASTM A694 F42, F46, F48, F50, F52, F56, F60, F65 ,F70;
Stainless Steel Flange: ASTM A182 F304, 304L, F316, 316L, 1Cr18Ni9Ti, 0Cr18Ni9Ti, 321, 18-8;
Alloy Steel Flange: ASTM A182 F1, F5a, F9, F11, F12, F22, F91, A182F12, A182F11, 16MnR, Cr5Mo, 12Cr1MoV, 15CrMo, 12Cr2Mo1, A335P22, St45.8/Ⅲ;

Sealing Surface Types For Weld Neck Flanges
RF (Raised Face);
FF (Flat Face);
M&F (Male-and-Female Face);
RTJ (Ring-Type Joint)
F (Female Face);
M (Male Face);
T&G (Tongue and Groove Face);
Among them, the uneven surface (MFM) is a matching use;

Weld Neck Flange Standards
ANSI, ASME, JIS, DIN, BS4504, SABS1123, EN1092-1, UNI, AS2129, GOST-12820


Slip-On Flanges


Specification of Slip-On Flanges
DN15-DN2000

Slip-On Flange Pressure Grade
PN series: PN2.5Mpa~PN40Mpa;
Class series: Class150~Class1500;

Slip-On Flange Standard
National standard of the People’s Republic of China: GB/T 9116-2010 Steel Slip-On Flange;
Chemical industry standards of the People’s Republic of China: PN series (European system) in HG/T20592~20635-2009, Class series (American system) in HG/T20592~20635-2009;

Slip-On Flange Materials
Carbon Steel Flange: ASTM A105, 20#, Q235, 16Mn, ASTM A350 LF1, LF2 CL1/CL2, LF3 CL1/CL2, ASTM A694 F42, F46, F48, F50, F52, F56, F60, F65 ,F70;
Stainless Steel Flange: ASTM A182 F304, 304L, F316, 316L, 1Cr18Ni9Ti, 0Cr18Ni9Ti, 321, 18-8;
Alloy Steel Flange: ASTM A182 F1, F5a, F9, F11, F12, F22, F91, A182F12, A182F11, 16MnR, Cr5Mo, 12Cr1MoV, 15CrMo, 12Cr2Mo1, A335P22, St45.8/Ⅲ;

Sealing Surface Types For Slip-On Flanges
RF (Raised Face);
FF (Flat Face);
MFM (Male-and-Female Face);
F (Female Face);
M (Male Face);
TG (Tongue and Groove Face);
Among them, the uneven surface (MFM) is a matching use;


Blind Flanges


Specification of Blind Flanges
DN15-DN2000
General use OD range: 1/2”, 2”, 3”, 4”, 6”, 8”, 10”, 12”, to 24”, Up to 60”(special made OD).
Surface Treatment: Anti-rust Oil, Transparent/Yellow/Black Anti-rust Paint,Zinc,Hot dipped Galvanized.

Blind Flange Pressure Grade
PN2.5, PN6, PN10, PN16, PN25, PN40, PN63, PN100, PN160, PN250, PN320, PN400
Class 150, Class 300, Class 600, Class 900, Class 1500, Class 2500

Blind Flange Materials
Carbon Steel Flange: ASTM A105, 20#, Q235, 16Mn, ASTM A350 LF1, LF2 CL1/CL2, LF3 CL1/CL2, ASTM A694 F42, F46, F48, F50, F52, F56, F60, F65 ,F70;
Stainless Steel Flange: ASTM A182 F304, 304L, F316, 316L, 1Cr18Ni9Ti, 0Cr18Ni9Ti, 321, 18-8;
Alloy Steel Flange: ASTM A182 F1, F5a, F9, F11, F12, F22, F91, A182F12, A182F11, 16MnR, Cr5Mo, 12Cr1MoV, 15CrMo, 12Cr2Mo1, A335P22, St45.8/Ⅲ;

Blind Pipe Flange Face Types
RF (Raised Face);
FF (Flat Face);
M&F (Male-and-Female Face);
RTJ (Ring-Type Joint)
F (Female Face);
M (Male Face);
T&G (Tongue and Groove Face);

Blind Pipe Flange Standards
ANSI, ASME, JIS, DIN, BS4504, SABS1123, EN1092-1, UNI, AS2129, GOST-12820
Steel Pipe Flange: GB/T 9123-2010
Marine Steel Blind Flange: GB/T4450-1995
Ministry of Chemical Industry Standards: HG20592-2009, HG20615-2009, HG20601-97
Machinery Department Standard: JB/T86.1-94, JB/T86.2-94
Power Standard: D-GD86-0513


Socket Welded Flange


Socket Welded Flange Face Types
SW Flange: DN15-DN80
Outer Diameters: 1/2 inch to 48 inch, up to 1500#
Surface Treatment: Anti-rust Oil, Transparent/Yellow/Black Anti-rust Paint,Zinc,Hot dipped Galvanized.

Socket Weld Flange Pressure Grade
PN≤26.0MPa

SW Flange Standards
ANSI B16.5
HG20619-1997
GB/T9117.1-2000—GB/T9117.4-200
HG20597-1997

Socket Weld Flange Materials
Carbon Steel Flange: ASTM A105, 20#, Q235, 16Mn, ASTM A350 LF1, LF2 CL1/CL2, LF3 CL1/CL2, ASTM A694 F42, F46, F48, F50, F52, F56, F60, F65 ,F70;
Stainless Steel Flange: ASTM A182 F304, 304L, F316, 316L, 1Cr18Ni9Ti, 0Cr18Ni9Ti, 321, 18-8;
Alloy Steel Flange: ASTM A182 F1, F5a, F9, F11, F12, F22, F91, A182F12, A182F11, 16MnR, Cr5Mo, 12Cr1MoV, 15CrMo, 12Cr2Mo1, A335P22, St45.8/Ⅲ;

Socket Welded Flange Face Types
RF (Raised Face)
M&F (Male-and-Female Face)
RTJ (Ring-Type Joint)
T&G (Tongue and Groove Face)


Threaded Flanges



Specification of Threaded Flanges
DN15-DN600
Surface Treatment: Anti-rust Oil, Transparent/Yellow/Black Anti-rust Paint,Zinc,Hot dipped Galvanized.

Threaded Flange Materials
Carbon Steel Flange: ASTM A105, 20#, Q235, 16Mn, ASTM A350 LF1, LF2 CL1/CL2, LF3 CL1/CL2, ASTM A694 F42, F46, F48, F50, F52, F56, F60, F65 ,F70;
Stainless Steel Flange: ASTM A182 F304, 304L, F316, 316L, 1Cr18Ni9Ti, 0Cr18Ni9Ti, 321, 18-8;
Alloy Steel Flange: ASTM A182 F1, F5a, F9, F11, F12, F22, F91, A182F12, A182F11, 16MnR, Cr5Mo, 12Cr1MoV, 15CrMo, 12Cr2Mo1, A335P22, St45.8/Ⅲ;

Threaded Pipe Flange Standards
ANSI B16.5

Threaded Flange Pressure Grade
ANSI class 150, 300, 400, 600, 900, 1500, 2500

Sealing Surface Types For Threaded Pipe Flanges
RF (Raised Face);
FF (Flat Face);
M&F (Male-and-Female Face);
RTJ (Ring-Type Joint)
F (Female Face);
M (Male Face);
T&G (Tongue and Groove Face);


Lap Joint Flanges


Specification of Lap Joint Flanges
LJ Forged Flange: DN15-DN600
Surface Treatment: Anti-rust Oil, Transparent/Yellow/Black Anti-rust Paint,Zinc,Hot dipped Galvanized.

Lap Joint Flange Pressure Grade
PN0.25MPa,PN0.6MPa,PN1.0MPa,PN1.6MPa,PN2.5MPa,PN4.0MPa;

Lap Joint Flange Standards
ANSI B16.5
Male Face Steel Butt Weld Ring Lap Joint Pipe Flange with Neck: GB/T 9118.1-2000;
Ring Lap Steel Joint Pipe Flange with Neck: GB/T 9118.2-2000;
Butt Welding Lap Joint Pipe Flange: HG 20599-1997;
Flat Welding Lap Joint Pipe Flange: HG 20600-1997;

Sealing Surface Types For Lap Joint Pipe Flanges
RF (Raised Face);
FF (Flat Face);
M&F (Male-and-Female Face);
RTJ (Ring-Type Joint)
F (Female Face);
M (Male Face);
T&G (Tongue and Groove Face);

Lap Joint Flange Materials
Carbon Steel Flange: ASTM A105, 20#, Q235, 16Mn, ASTM A350 LF1, LF2 CL1/CL2, LF3 CL1/CL2, ASTM A694 F42, F46, F48, F50, F52, F56, F60, F65 ,F70;
Stainless Steel Flange: ASTM A182 F304, 304L, F316, 316L, 1Cr18Ni9Ti, 0Cr18Ni9Ti, 321, 18-8;
Alloy Steel Flange: ASTM A182 F1, F5a, F9, F11, F12, F22, F91, A182F12, A182F11, 16MnR, Cr5Mo, 12Cr1MoV, 15CrMo, 12Cr2Mo1, A335P22, St45.8/Ⅲ;


Differenet faceing on flange


Raised Face Flange (RF) 


Flat Face Flange (FF)


Ring Type Joint (RTJ)


Tongue and Groove (T/G)

Usage of pipe flange

For pipe connection
Pipe flanges are used to connect a series of pipes for water system.


For connecting valve
Pipe flanges are used to connect valves to control the flow within a water system.


To conect pump

To integrate pump to power the flow of water in line.


A Pipe Flange is a raised ridge, lip or edge, whether external or internal, used to add strength; to facilitate connection/transmit contact forces with other objects; or to stabilize and guide the movement of a machine or its components. The term Pipe Flange is also used for a tool used to form Pipe Flanges. Pipe Flanges can also be plates or rings to form an edge at the end of the pipe when secured to the pipe. A blind Pipe Flange is a plate used to cover or close off the end of a pipe. A Pipe Flange joint is a connection of pipes in which the joints have Pipe Flanges and the parts are connected together by Pipe Flange bolts. While the word "Pipe Flange" often refers to the actual raised edge or lip of the fitting, many Pipe Flanged pipe fittings are themselves Pipe Flanges.


Pipe Flanges are used to connect special items such as pipes, valves, fittings and filters and pressure vessels. Cover plates can be attached to form blind Pipe Flanges. Pipe Flanges are connected by bolts, and sealing is usually done with gaskets or other methods. Mechanical devices to mitigate the effects of leaks, such as spray shields or specific spray Pipe Flanges, may be included. Industries that process flammable, volatile, toxic or corrosive substances require special protection at Pipe Flange connections. Pipe Flange guards can provide a higher level of protection for safety.




Nominal Pipe Size NPS (inches) Class 150
Diameter ofFlange (inches) No. of Bolts Diameter of Bolts (inches) Bolt Circle (inches)
1/4 3-3/8 4 1/2 2-1/4
1/2 3-1/2 4 1/2 2-3/8
3/4 3-7/8 4 1/2 2-3/4
1 4-1/4 4 1/2 3-1/8
1-1/4 4-5/8 4 1/2 3-1/2
1-1/2 5 4 1/2 3-7/8
2 6 4 5/8 4-3/4
2-1/2 7 4 5/8 5-1/2
3 7-1/2 4 5/8 6
3-1/2 8-1/2 8 5/8 7
4 9 8 5/8 7-1/2
5 10 8 3/4 8-1/2
6 11 8 3/4 9-1/2
8 13-1/2 8 3/4 11-3/4
10 16 12 7/8 14-1/4
12 19 12 7/8 17
14 21 12 1 18-3/4
16 23-1/2 16 1 21-1/4
18 25 16 1-1/8 22-3/4
20 27-1/2 20 1-1/8 25
24 32 20 1-1/4 29-1/2
Nominal Pipe Size NPS (inches) Class 300
Diameter of Flange (inches) No. of Bolts Diameter of Bolts (inches) Bolt Circle (inches)
1/4 3-3/8 4 1/2 2-1/4
1/2 3-3/4 4 1/2 2-5/8
3/4 4-5/8 4 5/8 3-1/4
1 4-7/8 4 5/8 3-1/2
1-1/4 5-1/4 4 5/8 3-7/8
1-1/2 6-1/8 4 3/4 4-1/2
2 6-1/2 8 5/8 5
2-1/2 7-1/2 8 3/4 5-7/8
3 8-1/4 8 3/4 6-5/8
3-1/2 9 8 3/4 7-1/4
4 10 8 3/4 7-7/8
5 11 8 3/4 9-1/4
6 12-1/2 12 3/4 10-5/8
8 15 12 7/8 13
10 17-1/2 16 1 15-1/4
12 20-1/2 16 1-1/8 17-3/4
14 23 20 1-1/8 20-1/4
16 25-1/2 20 1-1/4 22-1/2
18 28 24 1-1/4 24-3/4
20 30-1/2 24 1-1/4 27
24 36 24 1-1/2 32
Nominal Pipe Size NPS (inches) Class 400
Diameter of Flange (inches) No. of Bolts Diameter of Bolts (inches) Bolt Circle (inches)
1/4 3-3/8 4 1/2 2-1/4
1/2 3-3/4 4 1/2 2-5/8
3/4 4-5/8 4 5/8 3-1/4
1 4-7/8 4 5/8 3-1/2
1-1/4 5-1/4 4 5/8 3-7/8
1-1/2 6-1/8 4 3/4 4-1/2
2 6-1/2 8 5/8 5
2-1/2 7-1/2 8 3/4 5-7/8
3 8-1/4 8 3/4 6-5/8
3-1/2 9 8 7/8 7-1/4
4 10 8 7/8 7-7/8
5 11 8 7/8 9-1/4
6 12-1/2 12 7/8 10-5/8
8 15 12 1 13
10 17-1/2 16 1-1/8 15-1/4
12 20-1/2 16 1-1/4 17-3/4
14 23 20 1-1/4 20-1/4
16 25-1/2 20 1-3/8 22-1/2
18 28 24 1-3/8 24-3/4
20 30-1/2 24 1-1/2 27
24 36 24 1-3/4 32
Nominal Pipe Size NPS (inches) Class 600
Diameter of Flange (inches) No. of Bolts Diameter of Bolts (inches) Bolt Circle (inches)
1/4 3-3/8 4 1/2 2-1/4
1/2 3-3/4 4 1/2 2-5/8
3/4 4-5/8 4 5/8 3-1/4
1 4-7/8 4 5/8 3-1/2
1-1/4 5-1/4 4 5/8 3-7/8
1-1/2 6-1/8 4 3/4 4-1/2
2 6-1/2 8 5/8 5
2-1/2 7-1/2 8 3/4 5-7/8
3 8-1/4 8 3/4 6-5/8
3-1/2 9 8 7/8 7-1/4
4 10-3/4 8 7/8 8-1/2
5 13 8 1 10-1/2
6 14 12 1 11-1/2
8 16-1/2 12 1-1/8 13-3/4
10 20 16 1-1/4 17
12 22 20 1-1/4 19-1/4
14 23-3/4 20 1-3/8 20-3/4
16 27 20 1-1/2 23-3/4
18 29-1/4 20 1-5/8 25-3/4
20 32 24 1-5/8 28-1/2
24 37 24 1-7/8 33
Nominal Pipe Size NPS (inches) Class 900
Diameter of Flange (inches) No. of Bolts Diameter of Bolts (inches) Bolt Circle (inches)
1/2 4-3/4 4 3/4 3-1/4
3/4 5-1/8 4 3/4 3-1/2
1 5-7/8 4 7/8 4
1-1/4 6-1/4 4 7/8 4-3/8
1-1/2 7 4 1 4-7/8
2 8-1/2 8 7/8 6-1/2
2-1/2 9-5/8 8 1 7-1/2
3 9-1/2 8 7/8 7-1/2
4 11-1/2 8 1-1/8 9-1/4
5 13-3/4 8 1-1/4 11
6 15 12 1-1/8 12-1/2
8 18-1/2 12 1-3/8 15-1/2
10 21-1/2 16 1-3/8 18-1/2
12 24 20 1-3/8 21
14 25-1/4 20 1-1/2 22
16 27-3/4 20 1-5/8 24-1/2
18 31 20 1-7/8 27
20 33-3/4 20 2 29-1/2
24 41 20 2-1/2 35-1/2
Nominal Pipe Size NPS (inches) Class 1500
Diameter of Flange (inches) No. of Bolts Diameter of Bolts (inches) Bolt Circle (inches)
1/2 4-3/4 4 3/4 3-1/4
3/4 5-1/8 4 3/4 3-1/2
1 5-7/8 4 7/8 4
1-1/4 6-1/4 4 7/8 4-3/8
1-1/2 7 4 1 4-7/8
2 8-1/2 8 7/8 6-1/2
2-1/2 9-5/8 8 1 7-1/2
3 10-1/2 8 1-1/8 8
4 12-1/4 8 1-1/4 9-1/2
5 14-3/4 8 1-1/2 11-1/2
6 15-1/2 12 1-3/8 12-1/2
8 19 12 1-5/8 15-1/2
10 23 12 1-7/8 19
12 26-1/2 16 2 22-1/2
14 29-1/2 16 2-1/4 25
16 32-1/2 16 2-1/2 27-3/4
18 36 16 2-3/4 30-1/2
20 38-3/4 16 3 32-3/4
24 46 16 3-1/2 39
Nominal Pipe Size NPS (inches) Class 2500
Diameter of Flange (inches) No. of Bolts Diameter of Bolts (inches) Bolt Circle (inches)
1/2 5-1/4 4 3/4 3-1/2
3/4 5-1/2 4 3/4 3-3/4
1 6-1/4 4 7/8 4-1/4
1-1/4 7-1/4 4 1 5-1/8
1-1/2 8 4 1-1/8 5-3/4
2 9-1/4 8 1 6-3/4
2-1/2 10-1/2 8 1-1/8 7-3/4
3 12 8 1-1/4 9
4 14 8 1-1/2 10-3/4
5 16-1/2 8 1-3/4 12-3/4
6 19 8 2 14-1/2
8 21-3/4 12 2 17-1/4
10 26-1/2 12 2-1/2 21-1/4
12 30 12 2-3/4 24-3/8


Nominal Pipe Size NPS (inches) Class 150
Diameter ofFlange (inches) No. of Bolts Diameter of Bolts (inches) Bolt Circle (inches)
1/4 3-3/8 4 1/2 2-1/4
1/2 3-1/2 4 1/2 2-3/8
3/4 3-7/8 4 1/2 2-3/4
1 4-1/4 4 1/2 3-1/8
1-1/4 4-5/8 4 1/2 3-1/2
1-1/2 5 4 1/2 3-7/8
2 6 4 5/8 4-3/4
2-1/2 7 4 5/8 5-1/2
3 7-1/2 4 5/8 6
3-1/2 8-1/2 8 5/8 7
4 9 8 5/8 7-1/2
5 10 8 3/4 8-1/2
6 11 8 3/4 9-1/2
8 13-1/2 8 3/4 11-3/4
10 16 12 7/8 14-1/4
12 19 12 7/8 17
14 21 12 1 18-3/4
16 23-1/2 16 1 21-1/4
18 25 16 1-1/8 22-3/4
20 27-1/2 20 1-1/8 25
24 32 20 1-1/4 29-1/2
Nominal Pipe Size NPS (inches) Class 300
Diameter of Flange (inches) No. of Bolts Diameter of Bolts (inches) Bolt Circle (inches)
1/4 3-3/8 4 1/2 2-1/4
1/2 3-3/4 4 1/2 2-5/8
3/4 4-5/8 4 5/8 3-1/4
1 4-7/8 4 5/8 3-1/2
1-1/4 5-1/4 4 5/8 3-7/8
1-1/2 6-1/8 4 3/4 4-1/2
2 6-1/2 8 5/8 5
2-1/2 7-1/2 8 3/4 5-7/8
3 8-1/4 8 3/4 6-5/8
3-1/2 9 8 3/4 7-1/4
4 10 8 3/4 7-7/8
5 11 8 3/4 9-1/4
6 12-1/2 12 3/4 10-5/8
8 15 12 7/8 13
10 17-1/2 16 1 15-1/4
12 20-1/2 16 1-1/8 17-3/4
14 23 20 1-1/8 20-1/4
16 25-1/2 20 1-1/4 22-1/2
18 28 24 1-1/4 24-3/4
20 30-1/2 24 1-1/4 27
24 36 24 1-1/2 32
Nominal Pipe Size NPS (inches) Class 400
Diameter of Flange (inches) No. of Bolts Diameter of Bolts (inches) Bolt Circle (inches)
1/4 3-3/8 4 1/2 2-1/4
1/2 3-3/4 4 1/2 2-5/8
3/4 4-5/8 4 5/8 3-1/4
1 4-7/8 4 5/8 3-1/2
1-1/4 5-1/4 4 5/8 3-7/8
1-1/2 6-1/8 4 3/4 4-1/2
2 6-1/2 8 5/8 5
2-1/2 7-1/2 8 3/4 5-7/8
3 8-1/4 8 3/4 6-5/8
3-1/2 9 8 7/8 7-1/4
4 10 8 7/8 7-7/8
5 11 8 7/8 9-1/4
6 12-1/2 12 7/8 10-5/8
8 15 12 1 13
10 17-1/2 16 1-1/8 15-1/4
12 20-1/2 16 1-1/4 17-3/4
14 23 20 1-1/4 20-1/4
16 25-1/2 20 1-3/8 22-1/2
18 28 24 1-3/8 24-3/4
20 30-1/2 24 1-1/2 27
24 36 24 1-3/4 32
Nominal Pipe Size NPS (inches) Class 600
Diameter of Flange (inches) No. of Bolts Diameter of Bolts (inches) Bolt Circle (inches)
1/4 3-3/8 4 1/2 2-1/4
1/2 3-3/4 4 1/2 2-5/8
3/4 4-5/8 4 5/8 3-1/4
1 4-7/8 4 5/8 3-1/2
1-1/4 5-1/4 4 5/8 3-7/8
1-1/2 6-1/8 4 3/4 4-1/2
2 6-1/2 8 5/8 5
2-1/2 7-1/2 8 3/4 5-7/8
3 8-1/4 8 3/4 6-5/8
3-1/2 9 8 7/8 7-1/4
4 10-3/4 8 7/8 8-1/2
5 13 8 1 10-1/2
6 14 12 1 11-1/2
8 16-1/2 12 1-1/8 13-3/4
10 20 16 1-1/4 17
12 22 20 1-1/4 19-1/4
14 23-3/4 20 1-3/8 20-3/4
16 27 20 1-1/2 23-3/4
18 29-1/4 20 1-5/8 25-3/4
20 32 24 1-5/8 28-1/2
24 37 24 1-7/8 33
Nominal Pipe Size NPS (inches) Class 900
Diameter of Flange (inches) No. of Bolts Diameter of Bolts (inches) Bolt Circle (inches)
1/2 4-3/4 4 3/4 3-1/4
3/4 5-1/8 4 3/4 3-1/2
1 5-7/8 4 7/8 4
1-1/4 6-1/4 4 7/8 4-3/8
1-1/2 7 4 1 4-7/8
2 8-1/2 8 7/8 6-1/2
2-1/2 9-5/8 8 1 7-1/2
3 9-1/2 8 7/8 7-1/2
4 11-1/2 8 1-1/8 9-1/4
5 13-3/4 8 1-1/4 11
6 15 12 1-1/8 12-1/2
8 18-1/2 12 1-3/8 15-1/2
10 21-1/2 16 1-3/8 18-1/2
12 24 20 1-3/8 21
14 25-1/4 20 1-1/2 22
16 27-3/4 20 1-5/8 24-1/2
18 31 20 1-7/8 27
20 33-3/4 20 2 29-1/2
24 41 20 2-1/2 35-1/2
Nominal Pipe Size NPS (inches) Class 1500
Diameter of Flange (inches) No. of Bolts Diameter of Bolts (inches) Bolt Circle (inches)
1/2 4-3/4 4 3/4 3-1/4
3/4 5-1/8 4 3/4 3-1/2
1 5-7/8 4 7/8 4
1-1/4 6-1/4 4 7/8 4-3/8
1-1/2 7 4 1 4-7/8
2 8-1/2 8 7/8 6-1/2
2-1/2 9-5/8 8 1 7-1/2
3 10-1/2 8 1-1/8 8
4 12-1/4 8 1-1/4 9-1/2
5 14-3/4 8 1-1/2 11-1/2
6 15-1/2 12 1-3/8 12-1/2
8 19 12 1-5/8 15-1/2
10 23 12 1-7/8 19
12 26-1/2 16 2 22-1/2
14 29-1/2 16 2-1/4 25
16 32-1/2 16 2-1/2 27-3/4
18 36 16 2-3/4 30-1/2
20 38-3/4 16 3 32-3/4
24 46 16 3-1/2 39
Nominal Pipe Size NPS (inches) Class 2500
Diameter of Flange (inches) No. of Bolts Diameter of Bolts (inches) Bolt Circle (inches)
1/2 5-1/4 4 3/4 3-1/2
3/4 5-1/2 4 3/4 3-3/4
1 6-1/4 4 7/8 4-1/4
1-1/4 7-1/4 4 1 5-1/8
1-1/2 8 4 1-1/8 5-3/4
2 9-1/4 8 1 6-3/4
2-1/2 10-1/2 8 1-1/8 7-3/4
3 12 8 1-1/4 9
4 14 8 1-1/2 10-3/4
5 16-1/2 8 1-3/4 12-3/4
6 19 8 2 14-1/2
8 21-3/4 12 2 17-1/4
10 26-1/2 12 2-1/2 21-1/4
12 30 12 2-3/4 24-3/8



ASTM A105 – Forged Carbon Steel
ASTM A181 – Forged Carbon Steel for General Purpose
ASTM A182 – Forged Alloy Steel and Stainless Steel
ASTM A350 – Forged Alloy Steel for low temperature services

flange