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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About Vacuum Pumps
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Flow Sights with Barbed Fittings for Water, Oil, Air, and Inert Gas


Monitor liquid movement, color, and clarity in tube systems—these sights have barbed fittings that slide into soft plastic and rubber tubing. They have a clear body and an indicator that moves when flow is present, so you can visually confirm flow from a distance.
Indicator | ||||||||||
---|---|---|---|---|---|---|---|---|---|---|
For Tube ID | Temp. Range, °F | End-to-End Lg. | Ht. | Max. Pressure | Direction of Flow | Material | Color | For Use With | Each | |
Ball Indicator | ||||||||||
Polycarbonate Plastic Body | ||||||||||
1/4" to 3/8" | 32° to 180° | 3" | 2 1/4" | 10 psi @ 70° F | Bottom to Top, Left to Right, Right to Left, Top to Bottom | Nylon Plastic | White | Water, Oil, Air, Inert Gas | 0000000 | 000000 |
Rotor Indicator | ||||||||||
Polymethylpentene Plastic Body | ||||||||||
1/4" to 7/16" | 32° to 140° | 3 1/2" | 1 9/16" | 20 psi @ 70° F | Bottom to Top, Left to Right, Right to Left, Top to Bottom | Polypropylene Plastic | Blue | Water, Mineral Oil, Air, Inert Gas | 0000000 | 00000 |
Polystyrene Plastic Body | ||||||||||
3/16" to 1/4" | 0° to 190° | 2" | 1" | 10 psi @ 70° F | Bottom to Top, Left to Right, Right to Left, Top to Bottom | Polystyrene Plastic | Blue | Water, Oil, Air, Inert Gas | 0000000 | 00000 |
Panel-Mount Flow Sights for Water, Oil, and Inert Gas

The included mounting ring lets you install these sights in instrument panels. They have three ball indicators that bounce in the domed-top window to show flow in your line.
Flow Sights | |||||||||||||||
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Indicator | Repair Kits | ||||||||||||||
Pipe Size | Thread Type | Gender | Temp. Range, °F | Window Dia. | End-to-End Lg. | Ht. | Max. Pressure | Panel Cutout Dia. | Direction of Flow | No. of | Material | Each | Each | ||
Brass Body | |||||||||||||||
1/4 | NPT | Female | 35° to 120° | 1 5/8" | 3 1/8" | 2 1/8" | 150 psi @ 70° F | 2 3/8" | Bottom to Top, Left to Right, Right to Left, Top to Bottom | 3 | White Polyethylene Plastic White Polyethylene Plastic Green Acrylic Plastic | 0000000 | 0000000 | 00000000 | 000000 |
3/8 | NPT | Female | 35° to 120° | 1 5/8" | 3 1/8" | 2 1/8" | 150 psi @ 70° F | 2 3/8" | Bottom to Top, Left to Right, Right to Left, Top to Bottom | 3 | White Polyethylene Plastic White Polyethylene Plastic Green Acrylic Plastic | 0000000 | 000000 | 00000000 | 00000 |
1/2 | NPT | Female | 35° to 120° | 1 5/8" | 3 1/8" | 2 1/8" | 150 psi @ 70° F | 2 3/8" | Bottom to Top, Left to Right, Right to Left, Top to Bottom | 3 | White Polyethylene Plastic White Polyethylene Plastic Green Acrylic Plastic | 0000000 | 000000 | 00000000 | 00000 |
3/4 | NPT | Female | 35° to 120° | 1 5/8" | 3 1/8" | 2 1/8" | 150 psi @ 70° F | 2 3/8" | Bottom to Top, Left to Right, Right to Left, Top to Bottom | 3 | White Polyethylene Plastic White Polyethylene Plastic Green Acrylic Plastic | 0000000 | 000000 | 00000000 | 00000 |
1 | NPT | Female | 35° to 120° | 1 5/8" | 3 1/8" | 2 5/8" | 150 psi @ 70° F | 2 3/8" | Bottom to Top, Left to Right, Right to Left, Top to Bottom | 3 | White Polyethylene Plastic White Polyethylene Plastic Green Acrylic Plastic | 0000000 | 000000 | 00000000 | 00000 |
Sights for Quick-Clamp Sanitary Tube Fittings

Quick-Clamp Fitting, And Tube
Fitting (All Sold Separately)

Monitor food, brewery, chemical, pharmaceutical, and biotech processing lines with these sights that attach to quick-clamp fittings for fast installation and easy removal for cleaning. All have a one-piece design, so there are no crevices where bacteria can grow. A
For superior strength and reliability, choose 2205 stainless steel sights. All have a glass window that’s melted around a high-strength ring, so they won’t shatter, leak, or lose their shape under high pressure, heat, chemicals, or impact. They withstand harsh cleaners and sanitizers for clean-in-place (CIP) and steam-in-place (SIP) applications. USP Class VI and TUV Rheinland Certified, these sights meet safety standards in the U.S. and Europe. They also meet DIN standards for glass materials used in sights, ASTM standards for materials used in boilers and pressure vessels, and ASME BPE design standards for bioprocessing equipment that ensure purity and safety.
Temp. Range, °F | ||||||||||
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For Tube OD | For Flange OD | Window Dia. | Max. Pressure | Min. | Max. | For Use With | Features | Specifications Met | Each | |
2205 Stainless Steel Ring with Glass Window | ||||||||||
1", 1 1/2" | 1.98" | 1" | 230 psi @ 70° F | -40° | 500° | Water, Hydraulic Fluid, Diesel Fuel, Acetic Acid, Air, Alcohol-Based Solvents, Beverage, Chemicals, Compressed Air, Food, Fuel Oil, Gasoline, Inert Gas, Ketone, Oil, Salt Water, Steam | One-Piece Construction | ASME BPE, ASTM A479, DIN 7079, DIN 7080, TUV Rheinland Certified, USP Class VI | 0000000 | 0000000 |
2" | 2.52" | 1 3/16" | 230 psi @ 70° F | -40° | 500° | Water, Hydraulic Fluid, Diesel Fuel, Acetic Acid, Air, Alcohol-Based Solvents, Beverage, Chemicals, Compressed Air, Food, Fuel Oil, Gasoline, Inert Gas, Ketone, Oil, Salt Water, Steam | One-Piece Construction | ASME BPE, ASTM A479, DIN 7079, DIN 7080, TUV Rheinland Certified, USP Class VI | 0000000 | 000000 |
3" | 3.58" | 1 1/2" | 150 psi @ 70° F | -40° | 500° | Water, Hydraulic Fluid, Diesel Fuel, Acetic Acid, Air, Alcohol-Based Solvents, Beverage, Chemicals, Compressed Air, Food, Fuel Oil, Gasoline, Inert Gas, Ketone, Oil, Salt Water, Steam | One-Piece Construction | ASME BPE, ASTM A479, DIN 7079, DIN 7080, TUV Rheinland Certified, USP Class VI | 0000000 | 000000 |
4" | 4.68" | 2 3/16" | 150 psi @ 70° F | -40° | 500° | Water, Hydraulic Fluid, Diesel Fuel, Acetic Acid, Air, Alcohol-Based Solvents, Beverage, Chemicals, Compressed Air, Food, Fuel Oil, Gasoline, Inert Gas, Ketone, Oil, Salt Water, Steam | One-Piece Construction | ASME BPE, ASTM A479, DIN 7079, DIN 7080, TUV Rheinland Certified, USP Class VI | 0000000 | 000000 |
Oil-Free Electric High-Vacuum Pumps
Connect these pumps to a vacuum chamber to create high levels of vacuum—just plug them in and they’re ready to go. Since they don’t use oil, they won’t introduce contaminants into your system. They barely vibrate, which prevents interference with sensitive instruments and measurement devices. These pumps are small enough to fit on a workbench or table. They include both a diaphragm pump and a turbomolecular pump. The turbomolecular pump meets IP54 for protection in damp and dusty environments.
Pumps with claw-clamp intake connections (ISO-K) are rated for high-vacuum chambers. You’ll need a ring and four double-claw clamps (all sold separately) to connect them to other components. They include a gauge with quick-clamp (KF) connections, so you’ll also need a quick clamp and a ring (both sold separately) to connect it to your chamber.
Pumps with flanged intake connections (CF) are rated for ultra-high-vacuum chambers. You’ll need two gaskets (sold separately) to connect to your chamber: one for the intake and one for the included gauge.

Intake Connection | Gauge Port Connection | Discharge Connection (BSPP Threads) | O'all | ||||||||||||||
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Max. Vacuum | Max. Flow Rate, cfm | Volume, dBA | Current, A | 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 | Pipe Size | Gender | Ht. | Wd. | Each | |
Claw-Clamp Intake Connection—High Vacuum Rating | |||||||||||||||||
120V AC/240V AC, Single Phase | |||||||||||||||||
10 -8 torr @ 72° F | 142 | 50 | 4.6 | 2 1/2" | 3 3/4" | 63 | ISO-K | 1" | 1.57" | 25 | ISO-KF | 1/8 | Male | 13 5/8" | 11 7/8" | 000000 | 000000000 |
Flanged Intake Connection—Ultra-High Vacuum Rating | |||||||||||||||||
120V AC/240V AC, Single Phase | |||||||||||||||||
10 -12 torr @ 72° F | 142 | 50 | 4.6 | 2 1/2" | 4 1/2" | 63 | CF | 1 1/2" | 2 3/4" | 40 | CF | 1/8 | Male | 13 7/8" | 11 7/8" | 000000 | 00000000 |


For Tube OD | For Flange OD | For High-Vacuum Flange Size | High Vacuum Connection Type | Material | Max. Vacuum | Each | |
For Claw-Clamp Intake Connection—Double-Claw with Bolt | |||||||
---|---|---|---|---|---|---|---|
2 1/2", 3", 4" | 3.74", 4.33", 5.12" | 63, 80, 100 | ISO-K | Aluminum | 10 -8 torr @ 72° F | 0000000 | 00000 |
For Quick-Clamp Gauge Connection—Clamp with Wing Nut | |||||||
1" | 1.57" | 25 | ISO-KF | Aluminum | 10 -8 torr @ 72° F | 0000000 | 00000 |

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 | |
For Claw-Clamp Intake Connection | |||||||||
2 1/2" | 3.74" | 63 | ISO-K | Viton® Fluoroelastomer Rubber | 304 Stainless Steel | 10 -8 torr @ 72° F | 400° | 0000000 | 000000 |
For Quick-Clamp Gauge Connection | |||||||||
1" | 1.57" | 25 | ISO-KF | Viton® Fluoroelastomer Rubber | 304 Stainless Steel | 10 -8 torr @ 72° F | 300° | 0000000 | 00000 |