How to Identify and Measure Fittings
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Quick-Clamp High-Vacuum Fittings for Stainless Steel Tubing
- For Use With:
Fittings with Gasket End: Air, Argon, Helium, Nitrogen
All Other Fittings: Air - Specifications Met: ISO 2861
Instead of a gasket, these fittings have a metal-reinforced O-ring that is designed for high-vacuum applications, such as vacuum coating and heat treating, leak testing, and analyzing gases. Also known as KF, QF, and NW fittings, they are the most common type of connection in high-vacuum systems. Connect with a clamp and another quick-clamp fitting for fast, easy access to your line. To use fittings in pressure applications, use a pressure-rated ring (sold separately). Made of 304 stainless steel, these fittings have very good corrosion resistance.
Note: To complete a connection, you’ll need two quick-clamp fittings, a ring, and a clamp (all sold separately).
- Temperature Range: 0° to 300° F
- Tubing: Use with 304/304L or 316/316L stainless steel
Fittings with claw-clamp end are often used to connect high-vacuum components with large-diameter connections, such as coating or heat-treating equipment, to components with smaller connections such as gauges, filters, or pumps. Also known as ISO-K fittings, they connect with four claw clamps and a ring (sold separately).
Quick-Clamp Tube Connection | Claw-Clamp Tube Connection | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| For Tube OD | Flange OD | High-Vacuum Flange Size | High Vacuum Connection Type | For Tube OD | Flange OD | High-Vacuum Flange Size | High Vacuum Connection Type | Max. Vacuum | Max. Pressure | Each | |
| 1" | 1.57" | 25 | ISO-KF | 2 1/2" | 3.74" | 63 | ISO-K | 10 -8 torr @ 72° F | 5 psi @ 72° F | 00000000 | 0000000 |
| 1 1/2" | 2.16" | 40 | ISO-KF | 2 1/2" | 3.74" | 63 | ISO-K | 10 -8 torr @ 72° F | 5 psi @ 72° F | 00000000 | 000000 |
| 1 1/2" | 2.16" | 40 | ISO-KF | 3" | 4.33" | 80 | ISO-K | 10 -8 torr @ 72° F | 5 psi @ 72° F | 00000000 | 000000 |
| 1 1/2" | 2.16" | 40 | ISO-KF | 4" | 5.12" | 100 | ISO-K | 10 -8 torr @ 72° F | 5 psi @ 72° F | 00000000 | 000000 |
| 2" | 2.95" | 50 | ISO-KF | 2 1/2" | 3.74" | 63 | ISO-K | 10 -8 torr @ 72° F | 5 psi @ 72° F | 00000000 | 000000 |
| 2" | 2.95" | 50 | ISO-KF | 3" | 4.33" | 80 | ISO-K | 10 -8 torr @ 72° F | 5 psi @ 72° F | 00000000 | 000000 |
| 2" | 2.95" | 50 | ISO-KF | 4" | 5.12" | 100 | ISO-K | 10 -8 torr @ 72° F | 5 psi @ 72° F | 00000000 | 000000 |
- Temperature Range: 0° to 300° F
- Tubing: Use with 304/304L stainless steel, 316/316L stainless steel, or aluminum
Clamps tighten by hand.
Lever clamps are also known as toggle clamps.
Clamps with lanyard let you secure the clamp to equipment.
| For Tube OD | For Flange OD | For High-Vacuum Flange Size | High Vacuum Connection Type | Material | Max. Vacuum | Lanyard Lg. | Each | |
Wing Nut | ||||||||
|---|---|---|---|---|---|---|---|---|
| 1" | 1.57" | 25 | ISO-KF | Aluminum | 10 -8 torr @ 72° F | __ | 0000000 | 000000 |
| 1 1/2" | 2.16" | 40 | ISO-KF | Aluminum | 10 -8 torr @ 72° F | __ | 0000000 | 00000 |
| 2" | 2.95" | 50 | ISO-KF | Aluminum | 10 -8 torr @ 72° F | __ | 0000000 | 00000 |
Lever | ||||||||
| 1" | 1.57" | 25 | ISO-KF | Aluminum | 10 -8 torr @ 72° F | __ | 0000000 | 00000 |
| 1 1/2" | 2.16" | 40 | ISO-KF | Aluminum | 10 -8 torr @ 72° F | __ | 0000000 | 00000 |
| 2" | 2.95" | 50 | ISO-KF | Aluminum | 10 -8 torr @ 72° F | __ | 0000000 | 00000 |
Lever with Lanyard | ||||||||
| 1" | 1.57" | 25 | ISO-KF | Aluminum | 10 -8 torr @ 72° F | 5 3/4" | 00000000 | 00000 |
| 1 1/2" | 2.16" | 40 | ISO-KF | Aluminum | 10 -8 torr @ 72° F | 5 3/4" | 00000000 | 00000 |
| 2" | 2.95" | 50 | ISO-KF | Aluminum | 10 -8 torr @ 72° F | 5 3/4" | 00000000 | 00000 |
- Temperature Range:
Fittings with Viton® Fluoroelastomer Rubber O-Ring: 0° to 300° F
Fittings with Silicone Rubber O-Ring: -50° to 390°F - Tubing: Use with 304/304L stainless steel, 316/316L stainless steel, or aluminum
Use these rings with quick-clamp high-vacuum fittings. They consist of a stainless steel inner ring covered by an O-ring.
Silicone rings withstand higher temperatures than fluoroelastomer ones.
| For Tube OD | For Flange OD | For High-Vacuum Flange Size | High Vacuum Connection Type | Inner Ring Material | Max. Vacuum | Max. Pressure | Each | |
Viton® Fluoroelastomer Rubber O-Ring | ||||||||
|---|---|---|---|---|---|---|---|---|
Rings | ||||||||
| 1" | 1.57" | 25 | ISO-KF | 304 Stainless Steel | 10 -8 torr @ 72° F | Not Rated | 0000000 | 000000 |
| 1 1/2" | 2.16" | 40 | ISO-KF | 304 Stainless Steel | 10 -8 torr @ 72° F | Not Rated | 0000000 | 00000 |
| 2" | 2.95" | 50 | ISO-KF | 304 Stainless Steel | 10 -8 torr @ 72° F | Not Rated | 0000000 | 00000 |
Rings with Stainless Steel Screen | ||||||||
| 1" | 1.57" | 25 | ISO-KF | 304 Stainless Steel | 10 -8 torr @ 72° F | Not Rated | 00000000 | 00000 |
| 1 1/2" | 2.16" | 40 | ISO-KF | 304 Stainless Steel | 10 -8 torr @ 72° F | Not Rated | 00000000 | 00000 |
| 2" | 2.95" | 50 | ISO-KF | 304 Stainless Steel | 10 -8 torr @ 72° F | Not Rated | 00000000 | 00000 |
Rings with Aluminum Outer Ring | ||||||||
| 1" | 1.57" | 25 | ISO-KF | 304 Stainless Steel | 10 -8 torr @ 72° F | 100 psi @ 72° F | 0000000 | 00000 |
| 1 1/2" | 2.16" | 40 | ISO-KF | 304 Stainless Steel | 10 -8 torr @ 72° F | 75 psi @ 72° F | 0000000 | 00000 |
| 2" | 2.95" | 50 | ISO-KF | 304 Stainless Steel | 10 -8 torr @ 72° F | 50 psi @ 72° F | 0000000 | 00000 |
Silicone Rubber O-Ring | ||||||||
Rings | ||||||||
| 1" | 1.57" | 25 | ISO-KF | 304 Stainless Steel | 10 -8 torr @ 72° F | Not Rated | 00000000 | 00000 |
| 1 1/2" | 2.16" | 40 | ISO-KF | 304 Stainless Steel | 10 -8 torr @ 72° F | Not Rated | 00000000 | 00000 |
| 2" | 2.95" | 50 | ISO-KF | 304 Stainless Steel | 10 -8 torr @ 72° F | Not Rated | 00000000 | 00000 |
- Temperature Range: 0° to 300° F
- Tubing: Use with 304/304L stainless steel, 316/316L stainless steel, or aluminum
Hose absorbs moderate vibration
| For Tube OD | Flange OD | High-Vacuum Flange Size | High Vacuum Connection Type | Material | Max. Vacuum | Bend Radius | Flexibility | Each | |
4 3/16" Lg. | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| 1" | 1.57" | 25 | ISO-KF | 304 Stainless Steel | 10 -8 torr @ 72° F | __ | Flexible | 0000000 | 000000 |
| 1 1/2" | 2.16" | 40 | ISO-KF | 304 Stainless Steel | 10 -8 torr @ 72° F | __ | Flexible | 0000000 | 000000 |
| 2" | 2.95" | 50 | ISO-KF | 304 Stainless Steel | 10 -8 torr @ 72° F | __ | Flexible | 0000000 | 000000 |
12" Lg. | |||||||||
| 1" | 1.57" | 25 | ISO-KF | 304 Stainless Steel | 10 -8 torr @ 72° F | 1 3/8" | Flexible | 00000000 | 000000 |
| 1 1/2" | 2.16" | 40 | ISO-KF | 304 Stainless Steel | 10 -8 torr @ 72° F | 2 1/2" | Flexible | 00000000 | 000000 |
| 2" | 2.95" | 50 | ISO-KF | 304 Stainless Steel | 10 -8 torr @ 72° F | 3 1/4" | Flexible | 00000000 | 000000 |
24" Lg. | |||||||||
| 1" | 1.57" | 25 | ISO-KF | 304 Stainless Steel | 10 -8 torr @ 72° F | 1 3/8" | Flexible | 00000000 | 000000 |
| 1 1/2" | 2.16" | 40 | ISO-KF | 304 Stainless Steel | 10 -8 torr @ 72° F | 2 1/2" | Flexible | 00000000 | 000000 |
| 2" | 2.95" | 50 | ISO-KF | 304 Stainless Steel | 10 -8 torr @ 72° F | 3 1/4" | Flexible | 00000000 | 000000 |
39" Lg. | |||||||||
| 1" | 1.57" | 25 | ISO-KF | 304 Stainless Steel | 10 -8 torr @ 72° F | 1 3/8" | Flexible | 00000000 | 000000 |
| 1 1/2" | 2.16" | 40 | ISO-KF | 304 Stainless Steel | 10 -8 torr @ 72° F | 2 1/2" | Flexible | 00000000 | 000000 |
| 2" | 2.95" | 50 | ISO-KF | 304 Stainless Steel | 10 -8 torr @ 72° F | 3 1/4" | Flexible | 00000000 | 000000 |
- Temperature Range: 0° to 190° F
- Tubing: Use with 304/304L or 316/316L stainless steel
Valves are also known as vacuum isolation valves. They connect to a vacuum system so you can install gauges, release gases, and remove air. They operate manually and have a compact body that fits easily into tight spaces.
| Actuation | For Tube OD | Flange OD | High-Vacuum Flange Size | High Vacuum Connection Type | Max. Vacuum | Body Material | Overall Ht. | Overall Lg. | Each | |
| Manual | 1" | 1 9/16" | 25 | ISO-KF | 10 -8 torr @ 72° F | 304 Stainless Steel | 5 5/8" | 3" | 00000000 | 0000000 |
| Manual | 1 1/2" | 2 1/8" | 40 | ISO-KF | 10 -8 torr @ 72° F | 304 Stainless Steel | 6 3/8" | 3 7/8" | 00000000 | 000000 |
| Manual | 2" | 2 15/16" | 50 | ISO-KF | 10 -8 torr @ 72° F | 304 Stainless Steel | 8" | 4 1/2" | 00000000 | 000000 |
Claw-Clamp High-Vacuum Fittings for Stainless Steel Tubing
An alternative to bolt-together fittings, these fittings handle larger tube OD sizes than quick-clamp fittings. Also known as ISO-K high-vacuum fittings, the clamps have claws that grab hold of fittings with flanged ends. To complete a connection, use a ring and four clamps (sold separately). Not for use in pressure applications.
Double-claw clamps attach to the grooves on the fittings.
Single-claw clamps have a clamp on one end and an exposed bolt on the other. Thread the bolt-end directly into the body of pumps, valves, or other high-vacuum components.
| For Tube OD | Flange OD | High-Vacuum Flange Size | Socket Depth | High Vacuum Connection Type | No. of Claw Clamps Required | Material | Max. Vacuum | Each | |
| 2 1/2" | 3.74" | 63 | 7/32" | ISO-K | 4 | 304 Stainless Steel | 10 -8 torr @ 72° F | 0000000 | 000000 |
| 3" | 4.33" | 80 | 7/32" | ISO-K | 4 | 304 Stainless Steel | 10 -8 torr @ 72° F | 0000000 | 00000 |
| 4" | 5.12" | 100 | 7/32" | ISO-K | 4 | 304 Stainless Steel | 10 -8 torr @ 72° F | 0000000 | 00000 |
| 6" | 7.09" | 160 | 7/32" | ISO-K | 4 | 304 Stainless Steel | 10 -8 torr @ 72° F | 0000000 | 000000 |
| For Tube OD | Flange OD | High-Vacuum Flange Size | Wall Thick. | High Vacuum Connection Type | No. of Claw Clamps Required | Material | Max. Vacuum | Each | |
| 2 1/2" | 3.74" | 63 | 0.065" | ISO-K | 4 | 304 Stainless Steel | 10 -8 torr @ 72° F | 0000000 | 000000 |
| 3" | 4.33" | 80 | 0.065" | ISO-K | 4 | 304 Stainless Steel | 10 -8 torr @ 72° F | 0000000 | 000000 |
| 4" | 5.12" | 100 | 0.083" | ISO-K | 4 | 304 Stainless Steel | 10 -8 torr @ 72° F | 0000000 | 000000 |
| 6" | 7.09" | 160 | 0.083" | ISO-K | 4 | 304 Stainless Steel | 10 -8 torr @ 72° F | 0000000 | 000000 |
Material | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| For Tube OD | For Flange OD | For High-Vacuum Flange Size | High Vacuum Connection Type | O-Ring | Inner Ring | Max. Vacuum | Max. Temp., °F | Each | |
| 2 1/2" | 3.74" | 63 | ISO-K | Viton® Fluoroelastomer Rubber | 304 Stainless Steel | 10 -8 torr @ 72° F | 400° | 0000000 | 000000 |
| 3" | 4.33" | 80 | ISO-K | Viton® Fluoroelastomer Rubber | 304 Stainless Steel | 10 -8 torr @ 72° F | 400° | 000000 | 00000 |
| 4" | 5.12" | 100 | ISO-K | Viton® Fluoroelastomer Rubber | 304 Stainless Steel | 10 -8 torr @ 72° F | 400° | 0000000 | 00000 |
| 6" | 7.09" | 160 | ISO-K | Viton® Fluoroelastomer Rubber | 304 Stainless Steel | 10 -8 torr @ 72° F | 400° | 0000000 | 00000 |
| For Tube OD | For Flange OD | For High-Vacuum Flange Size | High Vacuum Connection Type | Bolt Material | Max. Vacuum | Each | |
Double Claw | |||||||
|---|---|---|---|---|---|---|---|
Aluminum | |||||||
| 2 1/2", 3", 4" | 3.74", 4.33", 5.12" | 63, 80, 100 | ISO-K | 18-8 Stainless Steel | 10 -8 torr @ 72° F | 0000000 | 00000 |
| 6" | 7.09" | 160 | ISO-K | 18-8 Stainless Steel | 10 -8 torr @ 72° F | 0000000 | 0000 |
Single Claw | |||||||
Aluminum | |||||||
| 2 1/2", 3", 4" | 3.74", 4.33", 5.12" | 63, 80, 100 | ISO-K | 18-8 Stainless Steel | 10 -8 torr @ 72° F | 0000000 | 0000 |
| 6" | 7.09" | 160 | ISO-K | 18-8 Stainless Steel | 10 -8 torr @ 72° F | 0000000 | 0000 |
Clamps for Claw-Clamp High-Vacuum Fittings for Stainless Steel Tubing
Connect claw-clamp high-vacuum fittings for an airtight seal. For a complete connection, you'll need four clamps and a ring (sold separately).
Double-claw clamps attach to the grooves on the fittings.
Single-claw clamps have a clamp on one end and an exposed bolt on the other. Thread the bolt-end directly into the body of pumps, valves, or other high-vacuum components.
316 stainless steel clamps have excellent corrosion resistance.
| For Tube OD | For Flange OD | For High-Vacuum Flange Size | High Vacuum Connection Type | Bolt Material | Max. Vacuum | Each | |
Double Claw | |||||||
|---|---|---|---|---|---|---|---|
Aluminum | |||||||
| 2 1/2", 3", 4" | 3.74", 4.33", 5.12" | 63, 80, 100 | ISO-K | 18-8 Stainless Steel | 10 -8 torr @ 72° F | 0000000 | 00000 |
| 6" | 7.09" | 160 | ISO-K | 18-8 Stainless Steel | 10 -8 torr @ 72° F | 0000000 | 0000 |
316 Stainless Steel | |||||||
| 2 1/2", 3", 4", 6", 8", 10" | 3.74", 4.33", 5.12", 7.09", 9.45", 11.42" | 63, 80, 100, 160, 200, 250 | ISO-K | 316 Stainless Steel | 10 -8 torr @ 72° F | 00000000 | 00000 |
| 12 3/4", 16", 20" | 14.57", 17.72", 21.65" | 320, 400, 500 | ISO-K | 316 Stainless Steel | 10 -8 torr @ 72° F | 00000000 | 00000 |
Single Claw | |||||||
Aluminum | |||||||
| 2 1/2", 3", 4" | 3.74", 4.33", 5.12" | 63, 80, 100 | ISO-K | 18-8 Stainless Steel | 10 -8 torr @ 72° F | 0000000 | 0000 |
| 6" | 7.09" | 160 | ISO-K | 18-8 Stainless Steel | 10 -8 torr @ 72° F | 0000000 | 0000 |
Material | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| For Tube OD | For Flange OD | For High-Vacuum Flange Size | High Vacuum Connection Type | O-Ring | Inner Ring | Max. Vacuum | Max. Temp., °F | Each | |
| 2 1/2" | 3.74" | 63 | ISO-K | Viton® Fluoroelastomer Rubber | 304 Stainless Steel | 10 -8 torr @ 72° F | 400° | 0000000 | 000000 |
| 3" | 4.33" | 80 | ISO-K | Viton® Fluoroelastomer Rubber | 304 Stainless Steel | 10 -8 torr @ 72° F | 400° | 000000 | 00000 |
| 4" | 5.12" | 100 | ISO-K | Viton® Fluoroelastomer Rubber | 304 Stainless Steel | 10 -8 torr @ 72° F | 400° | 0000000 | 00000 |
| 6" | 7.09" | 160 | ISO-K | Viton® Fluoroelastomer Rubber | 304 Stainless Steel | 10 -8 torr @ 72° F | 400° | 0000000 | 00000 |
Rings for Claw-Clamp and Bolt-Together
High-Vacuum Fittings for Stainless Steel Tubing
- For Use With: Air
- Max. Temperature: 400° F
- Tubing: Use with 304/304L Stainless Steel or 316/316L Stainless Steel
Create airtight seals in high-vacuum systems by placing these rings between two claw-clamp (ISO-K) or bolt-together (ISO-F) fittings. They contain a Viton® fluoroelastomer O-ring—when you clamp or bolt your fittings together, the O-ring compresses to establish the seal.
Claw-Clamp Connection | Flanged Connection | Material | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| For Tube OD | For Flange OD | For High-Vacuum Flange Size | High Vacuum Connection Type | For Tube OD | For Flange OD | For High-Vacuum Flange Size | High Vacuum Connection Type | O-Ring | Inner Ring | Max. Vacuum | Each | |
| 2 1/2" | 3.74" | 63 | ISO-K | 2 1/2" | 5.12" | 63 | ISO-F | Viton® Fluoroelastomer Rubber | 304 Stainless Steel | 10 -8 torr @ 72° F | 0000000 | 000000 |
| 3" | 4.33" | 80 | ISO-K | 3" | 5.71" | 80 | ISO-F | Viton® Fluoroelastomer Rubber | 304 Stainless Steel | 10 -8 torr @ 72° F | 000000 | 00000 |
| 4" | 5.12" | 100 | ISO-K | 4" | 6.5" | 100 | ISO-F | Viton® Fluoroelastomer Rubber | 304 Stainless Steel | 10 -8 torr @ 72° F | 0000000 | 00000 |
| 6" | 7.09" | 160 | ISO-K | 6" | 8.86" | 160 | ISO-F | Viton® Fluoroelastomer Rubber | 304 Stainless Steel | 10 -8 torr @ 72° F | 0000000 | 00000 |