How to Identify and Measure Fittings
Pipe size is an industry designation, not the actual size. View information about how to measure threaded and unthreaded pipe and pipe fittings.
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High-Pressure Stainless Steel Unthreaded Pipe Flanges
Use these heavy duty forged flanges for high-pressure applications. Bolt two flat-surface flanges or two raised-surface flanges of same size together with a gasket (sold separately) to create an access point in a pipe line.
304 stainless steel flanges offer very good corrosion resistance. 316 stainless steel flanges have excellent corrosion resistance.
Butt-weld flanges are also known as weld-neck flanges; the flange neck has a beveled end that, when flush to pipe, creates a trough for a strong weld. Slip-on weld flanges have no internal stop; slide a pipe through the flange and weld on both sides. Socket-connect flanges have an internal stop that supports the pipe when welding and prevents the pipe from sliding all the way through.
Stub-end flanges are also known as lap-joint flanges; use them with a stub-end straight adapter (not included). The stub-end straight adapter slides into the flange and welds to pipe (not the flange). Since the flange isn’t welded to the pipe, it can be disconnected easily for frequent cleaning and inspecting. Cap flanges are also known as blind flanges.
For technical drawings and 3-D models, click on a part number.
- For Use With: Air, Hydraulic Fluid, Natural Gas, Oil, Steam, Water
- Pressure Class: See table
- Specifications Met:
Pressure Class 300: ASME B16.5, ASTM A182, MSS SP-25, MSS SP-6
Pressure Class 600: ASME B16.5, ASTM A182 - Certification: Material Certificate with Traceable Lot Number and Test Report
- Pipe Nipples and Pipe: Use Schedule 40 stainless steel
- Fittings: Use Schedule 40 stainless steel
Bolt Hole | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Pipe Size  | Dash Size | Flange OD | For Bolt Dia. | Dia. | No. of | Bolt Circle Dia. | Max. Pressure | Max. Steam Pressure | Each | |
304/304L Stainless Steel | ||||||||||
Pressure Class 300 | ||||||||||
| 3 | 48 | 8 1/4" | 3/4" | 0.875" | 8 | 6 5/8" | 600 psi @ 72° F | 415 psi @ 360° F | 00000000 | 0000000 |
316/316L Stainless Steel | ||||||||||
Pressure Class 300 | ||||||||||
| 3 | 48 | 8 1/4" | 3/4" | 0.875" | 8 | 6 5/8" | 600 psi @ 72° F | 415 psi @ 360° F | 00000000 | 000000 |
Pressure Class 600 | ||||||||||
| 3 | 48 | 8 1/4" | 3/4" | 0.88" | 8 | 6 5/8" | 1,200 psi @ 72° F | 825 psi @ 400° F | 0000000 | 000000 |
- For Use With:
4 and 6 Pipe Sizes: Air, Hydraulic Fluid, Natural Gas, Oil, Water
All other sizes: Air, Hydraulic Fluid, Natural Gas, Oil, Steam, Water - Pressure Class: See table
- Specifications Met: See table
- Certification:: Material Certificate with Traceable Lot Number and Test Report
- Pipe Nipples and Pipe: Use Schedule 40 stainless steel
- Fittings: Use Schedule 40 stainless steel
Bolt Hole | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Pipe Size | Dash Size | Max. Pressure | Max. Steam Pressure | Flange OD | For Bolt Dia. | Dia. | No. of | Bolt Circle Dia. | Specifications Met | Each | |
304/304L Stainless Steel | |||||||||||
Pressure Class 300 | |||||||||||
| 3 | 48 | 600 psi @ 72° F | 300 psi @ 360° F | 8 1/4" | 3/4" | 0.875" | 8 | 6 5/8" | ASME B16.5, ASTM A182, MSS SP-25, MSS SP-6 | 00000000 | 0000000 |
Pressure Class 600 | |||||||||||
| 3 | 48 | 1,200 psi @ 72° F | 840 psi @ 400° F | 8 1/4" | 3/4" | 0.88" | 8 | 6 5/8" | ASME B16.5, ASTM A182 | 0000000 | 000000 |
316/316L Stainless Steel | |||||||||||
Pressure Class 300 | |||||||||||
| 3 | 48 | 600 psi @ 72° F | 300 psi @ 360° F | 8 1/4" | 3/4" | 0.875" | 8 | 6 5/8" | ASME B16.5, ASTM A182, MSS SP-25, MSS SP-6 | 00000000 | 000000 |
- For Use With: Air, Hydraulic Fluid, Natural Gas, Oil, Steam, Water
- Pressure Class: See table
- Specifications Met:
Pressure Class 300: ASME B16.5, ASTM A182, MSS SP-25, MSS SP-6
Pressure Class 600: ASME B16.5, ASTM A182 - Certification:: Material Certificate with Traceable Lot Number and Test Report
- Pipe Nipples and Pipe: Use Schedule 40 stainless steel
- Fittings: Use Schedule 40 stainless steel
Bolt Hole | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Pipe Size | Dash Size | Max. Pressure | Max. Steam Pressure | Flange OD | For Bolt Dia. | Dia. | No. of | Bolt Circle Dia. | Each | |
304/304L Stainless Steel | ||||||||||
Pressure Class 300 | ||||||||||
| 3 | 48 | 600 psi @ 72° F | 300 psi @ 360° F | 8 1/4" | 3/4" | 0.875" | 8 | 6 5/8" | 00000000 | 0000000 |
Pressure Class 600 | ||||||||||
| 3 | 48 | 1,200 psi @ 72° F | 840 psi @ 400° F | 8 1/4" | 3/4" | 0.88" | 8 | 6 5/8" | 0000000 | 000000 |
316/316L Stainless Steel | ||||||||||
Pressure Class 300 | ||||||||||
| 3 | 48 | 600 psi @ 72° F | 300 psi @ 360° F | 8 1/4" | 3/4" | 0.875" | 8 | 6 5/8" | 00000000 | 000000 |
- For Use With: Air, Hydraulic Fluid, Natural Gas, Oil, Steam, Water
- Pressure Class: See table
- Specifications Met:
Pressure Class 300: ASME B16.5, ASTM A182, MSS SP-25, MSS SP-6
Pressure Class 600: ASME B16.5, ASTM A182 - Certification:: Material Certificate with Traceable Lot Number and Test Report
- Pipe Nipples and Pipe: Use Schedule 40 stainless steel
- Fittings: Use Schedule 40 stainless steel
Flanges | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Bolt Hole | Straight Adapters | |||||||||||
| Pipe Size | Dash Size | Max. Pressure | Max. Steam Pressure | Flange OD | For Bolt Dia. | Dia. | No. of | Bolt Circle Dia. | Each | Each | ||
304/304L Stainless Steel | ||||||||||||
Pressure Class 300 | ||||||||||||
| 3 | 48 | 600 psi @ 72° F | 300 psi @ 360° F | 8 1/4" | 3/4" | 0.875" | 8 | 6 5/8" | 00000000 | 0000000 | 000000000 | 000000 |
316/316L Stainless Steel | ||||||||||||
Pressure Class 300 | ||||||||||||
| 3 | 48 | 600 psi @ 72° F | 300 psi @ 360° F | 8 1/4" | 3/4" | 0.875" | 8 | 6 5/8" | 00000000 | 000000 | 000000000 | 00000 |
- For Use With: Air, Hydraulic Fluid, Natural Gas, Oil, Steam, Water
- Pressure Class: See table
- Specifications Met:
Pressure Class 300: ASME B16.5, ASTM A182, MSS SP-25, MSS SP-6
Pressure Class 600: ASME B16.5, ASTM A182 - Certification:: Material Certificate with Traceable Lot Number and Test Report
- Pipe Nipples and Pipe: Use Schedule 40 stainless steel
- Fittings: Use Schedule 40 stainless steel
Bolt Hole | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Pipe Size | Dash Size | Max. Pressure | Max. Steam Pressure | Flange OD | For Bolt Dia. | Dia. | No. of | Bolt Circle Dia. | Each | |
304/304L Stainless Steel | ||||||||||
Pressure Class 300 | ||||||||||
| 3 | 48 | 600 psi @ 72° F | 300 psi @ 360° F | 8 1/4" | 3/4" | 0.875" | 8 | 6 5/8" | 00000000 | 0000000 |
Pressure Class 600 | ||||||||||
| 3 | 48 | 1,200 psi @ 72° F | 840 psi @ 400° F | 8 1/4" | 3/4" | 0.88" | 8 | 6 5/8" | 0000000 | 000000 |
316/316L Stainless Steel | ||||||||||
Pressure Class 300 | ||||||||||
| 3 | 48 | 600 psi @ 72° F | 300 psi @ 360° F | 8 1/4" | 3/4" | 0.875" | 8 | 6 5/8" | 00000000 | 000000 |
Pressure Class 600 | ||||||||||
| 3 | 48 | 1,200 psi @ 72° F | 840 psi @ 400° F | 8 1/4" | 3/4" | 0.88" | 8 | 6 5/8" | 0000000 | 000000 |
High-Pressure Stainless Steel Threaded Pipe Flanges
- For Use With: Air, Hydraulic Fluid, Natural Gas, Oil, Steam, Water
- Pressure Class: See table
- Specifications Met: ASTM A182, ASME B16.5
- Pipe Nipples and Pipe: Use Schedule 80 stainless steel
Forged for high strength, these heavy duty flanges can handle high-pressure applications. They are also known as ANSI flanges. Bolt two same-size flanges together with a gasket (sold separately) to create an access point within a line.
304 stainless steel flanges provide very good corrosion resistance. 316 stainless steel flanges have excellent corrosion resistance.
For technical drawings and 3-D models, click on a part number.
Bolt Hole | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Pipe Size | Dash Size | Flange OD | For Bolt Dia. | Dia. | No. of | Bolt Circle Dia. | Max. Pressure | Max. Steam Pressure | Each | |
304/304L Stainless Steel | ||||||||||
NPT | ||||||||||
Pressure Class 300 | ||||||||||
| 3 | 48 | 8 1/4" | 3/4" | 0.88" | 8 | 6 5/8" | 600 psi @ 72° F | 300 psi @ 300° F | 0000000 | 0000000 |
Pressure Class 600 | ||||||||||
| 3 | 48 | 8 1/4" | 3/4" | 0.88" | 8 | 6 5/8" | 1,200 psi @ 72° F | 840 psi @ 400° F | 0000000 | 000000 |
316/316L Stainless Steel | ||||||||||
NPT | ||||||||||
Pressure Class 300 | ||||||||||
| 3 | 48 | 8 1/4" | 3/4" | 0.88" | 8 | 6 5/8" | 600 psi @ 72° F | 300 psi @ 300° F | 0000000 | 000000 |
Pressure Class 600 | ||||||||||
| 3 | 48 | 8 1/4" | 3/4" | 0.88" | 8 | 6 5/8" | 1,200 psi @ 72° F | 840 psi @ 400° F | 0000000 | 000000 |
High-Pressure Steel Unthreaded Pipe Flanges
Forged for extra strength, these heavy duty flanges can withstand high-pressure applications. Bolt two flat-surface flanges or two raised-surface flanges of the same size together with a gasket (sold separately) to create an access point in a pipe line.
Butt-weld flanges are also known as weld-neck flanges; the flange neck has a beveled end that, when flush to pipe, creates a trough for a strong weld.
Slip-on weld flanges have no internal stop; slide a pipe through the flange and weld on both sides.
Socket-connect flanges have an internal stop that supports the pipe when welding and prevents the pipe from sliding all the way through.
Stub-end flanges are also known as lap-joint flanges; use them with a stub-end straight adapter (not included). The stub-end straight adapter slides into the flange and welds to pipe (not the flange). Since the flange isn’t welded to the pipe, it can be disconnected easily for frequent cleaning and inspecting.
Cap flanges are also known as blind flanges.
For technical drawings and 3-D models, click on a part number.
- For Use With: Air, Hydraulic Fluid, Natural Gas, Oil, Steam, Water
- Pressure Class: See table
- Specifications Met: ASTM A105, ASME B16.5
- Certification: Material Certificate with Traceable Lot Number and Test Report
- Pipe Nipples and Pipe: Use Schedule 80 steel
- Fittings: Use Class 3000 and Schedule 80 steel
Bolt Hole | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Pipe Size | Dash Size | Wall Thick. | Flange OD | For Bolt Dia. | Dia. | No. of | Bolt Circle Dia. | Max. Pressure | Max. Steam Pressure | Material | Each | |
Pressure Class 300 | ||||||||||||
| 3 | 48 | 0.3" | 8 1/4" | 3/4" | 7/8" | 8 | 6 5/8" | 600 psi @ 72° F | 300 psi @ 300° F | Steel | 00000000 | 000000 |
Pressure Class 600 | ||||||||||||
| 3 | 48 | 0.3" | 8 1/4" | 0.88" | 0.88" | 8 | 6.62" | 1,400 psi @ 72° F | 1,300 psi @ 300° F | Steel | 00000000 | 00000 |
- For Use With: Air, Hydraulic Fluid, Natural Gas, Oil, Steam, Water
- Pressure Class: See table
- Specifications Met: ASTM A105, ASME B16.5
- Certification: Material Certificate with Traceable Lot Number and Test Report
- Pipe Nipples and Pipe: Use Schedule 80 steel
- Fittings: Use Class 3000 and Schedule 80 steel
Bolt Hole | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Pipe Size | Dash Size | Flange OD | For Bolt Dia. | Dia. | No. of | Bolt Circle Dia. | Max. Pressure | Max. Steam Pressure | Material | Each | |
Pressure Class 300 | |||||||||||
| 3 | 48 | 8 1/4" | 3/4" | 7/8" | 8 | 6 5/8" | 600 psi @ 72° F | 300 psi @ 300° F | Steel | 00000000 | 000000 |
Pressure Class 600 | |||||||||||
| 3 | 48 | 8 1/4" | 0.88" | 0.88" | 8 | 6.62" | 1,400 psi @ 72° F | 1,300 psi @ 300° F | Steel | 00000000 | 00000 |
- For Use With: Air, Hydraulic Fluid, Natural Gas, Oil, Steam, Water
- Pressure Class: See table
- Specifications Met: See table
- Certification: Material Certificate with Traceable Lot Number and Test Report
- Pipe Nipples and Pipe: Use Schedule 80 steel
- Fittings: Use Class 3000 and Schedule 80 steel
Bolt Hole | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Pipe Size | Dash Size | Flange OD | For Bolt Dia. | Dia. | No. of | Bolt Circle Dia. | Max. Pressure | Max. Steam Pressure | Material | Specifications Met | Each | |
Pressure Class 300 | ||||||||||||
| 3 | 48 | 8 1/4" | 3/4" | 7/8" | 8 | 6 5/8" | 600 psi @ 72° F | 300 psi @ 300° F | Steel | ASME B16.5, ASTM A105 | 00000000 | 000000 |
Pressure Class 600 | ||||||||||||
| 3 | 48 | 8 1/4" | 0.88" | 0.88" | 8 | 6.62" | 1,400 psi @ 72° F | 1,300 psi @ 300° F | Steel | ASME B16.5, ASTM A105 | 00000000 | 00000 |
- For Use With: Air, Hydraulic Fluid, Natural Gas, Oil, Steam, Water
- Pressure Class: See table
- Specifications Met: ASTM A105, ASME B16.5
- Certification: Material Certificate with Traceable Lot Number and Test Report
- Pipe Nipples and Pipe: Use Schedule 80 steel
- Fittings: Use Class 3000 and Schedule 80 steel
- For Use With: Air, Hydraulic Fluid, Natural Gas, Oil, Steam, Water
- Pressure Class: See table
- Specifications Met: ASTM A105, ASME B16.5
- Certification: Material Certificate with Traceable Lot Number and Test Report
- Pipe Nipples and Pipe: Use Schedule 80 steel
- Fittings: Use Class 3000 and Schedule 80 steel
Bolt Hole | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Pipe Size | Dash Size | Flange OD | For Bolt Dia. | Dia. | No. of | Bolt Circle Dia. | Max. Pressure | Max. Steam Pressure | Material | Each | |
Pressure Class 300 | |||||||||||
| 3 | 48 | 8 1/4" | 3/4" | 7/8" | 8 | 6 5/8" | 600 psi @ 72° F | 300 psi @ 300° F | Steel | 00000000 | 000000 |
Pressure Class 600 | |||||||||||
| 3 | 48 | 8 1/4" | 0.88" | 0.88" | 8 | 6.62" | 1,400 psi @ 72° F | 1,300 psi @ 300° F | Steel | 00000000 | 00000 |
Medium-Pressure Steel Threaded Pipe Flanges
- For Use With: Air, Natural Gas, Oil, Steam, Water
- Pressure Class: See table
- Specifications Met: ASTM A105, ASME B16.5
- Pipe Nipples and Pipe: Use Schedule 80 steel
- Fittings: Use Class 300 or Schedule 80 iron and steel
With better strength than our low-pressure steel flanges, these are for use in medium-pressure applications. Bolt two same-size flanges together with a gasket (sold separately) to create an access point within a line. Flanges are also known as Pressure Class 300 or Pressure Class 600 flanges. Use in noncorrosive environments.
For technical drawings and 3-D models, click on a part number.
Medium-Pressure Galvanized Steel Threaded Pipe Flanges
- For Use With: Air, Natural Gas, Steam, Water
- Pressure Class : 300
- Specifications Met: ASTM A123, ASTM A105, ASME B16.5
- Pipe Nipples and Pipe: Use Schedule 80 steel
- Fittings: Use Class 300 iron or steel
A galvanized finish gives these flanges fair corrosion resistance. Also known as Pressure Class 300 flanges, they can withstand medium-pressure applications. Bolt two same-size flanges together with a gasket (sold separately) to create an access point within a line.
For technical drawings and 3-D models, click on a part number.
Bolt Hole | ||||||||
|---|---|---|---|---|---|---|---|---|
| Pipe Size | Flange OD | For Bolt Dia. | Dia. | No. of | Bolt Circle Dia. | Max. Pressure | Each | |
NPT | ||||||||
| 3 | 8 1/4" | 7/8" | 0.88" | 8 | 6 5/8" | 600 psi @ 72° F | 0000000 | 0000000 |
Flow-Control Flange Unions
Measure, throttle, and regulate the flow of liquids and gases in your line by adding an orifice plate to these unions. They consist of two flange halves, plus all of the components needed to connect them together. Tighten the jack bolts to separate the flange halves to inspect or replace the orifice plate.
To throttle flow, mount an orifice plate between the two flanges. The orifice plate restricts the flow in order to regulate it.
To measure flow, build the same assembly, except you’ll also connect a differential pressure gauge or transmitter to both flange halves using the threaded ports. Your gauge or transmitter will measure the difference between the pressure before and after the orifice plate. The pressure difference is proportional to flow rate, so you can use that measurement to calculate your line’s flow rate.
Butt-weld flanges are also known as weld-neck flanges; the flange neck has a beveled end that, when flush to pipe, creates a trough for a strong weld. Slip-on weld flanges have no internal stop; slide a pipe through the flange and weld on both sides.
316/316L stainless steel flanges have excellent corrosion resistance.
Flanges that meet ASME B16.36 adhere to specifications and testing requirements for temperature and pressure ratings, dimensions, materials, and tolerances.
For technical drawings and 3-D models, click on a part number.
- For Use With: Air, Natural Gas, Oil, Water
- Temperature Range: Not Rated
- Specifications Met: See table
- Pressure Class: 300
- Fittings:
Carbon Steel: Use Schedule 40 steel
316/316L Stainless Steel: Use Schedule 40 stainless steel - Pipe Nipples and Pipe:
Carbon Steel: Use Schedule 40 steel
316/316L Stainless Steel: Use Schedule 40 stainless steel
Bolt Hole | Port | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Pipe Size | Construction | Flange OD | For Bolt Dia. | Dia. | No. of | Bolt Circle Dia. | Pipe Size | No. of | Includes | Specifications Met | Each | |
Carbon Steel | ||||||||||||
| 3 | Seamless | 8 1/4" | 3/4" | 13/16" | 8 | 6 9/16" | 1/2 NPT | 2 | Gaskets, Jack Bolts, Nuts, Port Plugs, Threaded Rods | ASME B16.36 | 0000000 | 0000000 |
316/316L Stainless Steel | ||||||||||||
| 3 | Seamless | 8 1/4" | 3/4" | 13/16" | 8 | 6 9/16" | 1/2 NPT | 2 | Gaskets, Jack Bolts, Nuts, Port Plugs, Threaded Rods | ASME B16.36 | 0000000 | 000000 |
- For Use With: Air, Natural Gas, Oil, Water
- Temperature Range: Not Rated
- Specifications Met: See table
- Pressure Class: 300
- Fittings:
Carbon Steel: Use Schedule 40 steel
316/316L Stainless Steel: Use Schedule 40 stainless steel - Pipe Nipples and Pipe:
Carbon Steel: Use Schedule 40 steel
316/316L Stainless Steel: Use Schedule 40 stainless steel
Bolt Hole | Port | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Pipe Size | Flange OD | For Bolt Dia. | Dia. | No. of | Bolt Circle Dia. | Pipe Size | No. of | Includes | Specifications Met | Each | |
Carbon Steel | |||||||||||
| 3 | 8 1/4" | 3/4" | 13/16" | 8 | 6 9/16" | 1/2 NPT | 2 | Gaskets, Jack Bolts, Nuts, Port Plugs, Threaded Rods | ASME B16.36 | 0000000 | 0000000 |
316/316L Stainless Steel | |||||||||||
| 3 | 8 1/4" | 3/4" | 13/16" | 8 | 6 9/16" | 1/2 NPT | 2 | Gaskets, Jack Bolts, Nuts, Port Plugs, Threaded Rods | ASME B16.36 | 0000000 | 00000000 |