Air Sight Glass | McMaster-Carr

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	Material Material

304 Stainless Steel

2205 Stainless Steel

	For Use With For Use With	Show

Air

	For Use With For Use With	Hide

Warning: Products have one, but not necessarily all, of the selected characteristics.

Acetic Acid

Air

Alcohol-Based Solvents

	Connection Style Connection Style

Quick Clamp

Flanged

Barbed

	Window Material Window Material

Glass

Plastic

	Maximum Temperature Maximum Temperature

Less than 250° F

250° to 499° F

500° to 999° F

	Minimum Temperature Minimum Temperature

	System of Measurement System of Measurement

Inch

	For Tube OD For Tube OD

3/4"

1 1/2"

2 1/2"

	Window Diameter Window Diameter

	Mount Type Mount Type

Clamp On

Bolt On

	Maximum Pressure Maximum Pressure

	Flange OD Flange OD

	Shape Shape

Cap/Plug

	Connection Type Connection Type

	Tube

	High Vacuum Connection Type High Vacuum Connection Type

ISO-KF

	Trade Number Trade Number

100

	Maximum Vacuum Maximum Vacuum

1 × 10^-11 torr
@ 72° F

1 × 10^-10 torr
@ 72° F

1 × 10^-9 torr
@ 72° F

1 × 10^-8 torr
@ 72° F

	Bolt Circle Diameter Bolt Circle Diameter

	For Flange OD For Flange OD

	Bolt Hole Diameter Bolt Hole Diameter

11/64"

17/64"

21/64"

	Number of Bolt Holes Number of Bolt Holes

	Environment Environment

Food and Beverage

Sanitary

	Specifications Met Specifications Met

ASME

ASTM

DIN

TUV Certified

USP

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59 Products

Sights for Quick-Clamp Sanitary Tube Fittings

Sight Shown Assembled With Gasket,
Quick-Clamp Fitting, And Tube
Fitting (All Sold Separately)

Plastic Window with 304 Stainless Steel Ring

Glass Window with 2205 Stainless Steel Ring

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 quick-clamp fitting, gasket, and tube fitting are required (sold separately).

304 stainless steel sights have a ring that's embedded around their shatter-resistant plastic window. This design protects the sights from chipping or cracking while under the stress of the quick-clamp fitting. All withstand harsh cleaners and sanitizers for clean-in-place (CIP) and steam-in-place (SIP) applications. They do not contain Bisphenol A (BPA), Bisphenol B (BPB), or BPA derivatives (BPX), which are chemicals that can contaminate your process lines. All meet ASME BPE design standards for bioprocessing equipment that ensure purity and safety.

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 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
For Tube OD	For Flange OD	Window Dia.	Max. Pressure	Min.	Max.	For Use With	Features	Specifications Met		Each
304 Stainless Steel Ring with Plastic Window
1"	1.98"	1 1/4"	150 psi @ 70° F	Not Rated	200°	Water, Acetic Acid, Air, Alcohol-Based Solvents, Compressed Air, Salt Water, Steam	One-Piece Construction	ASME BPE	0000000	000000
2"	2.52"	1 3/4"	150 psi @ 70° F	Not Rated	200°	Water, Acetic Acid, Air, Alcohol-Based Solvents, Compressed Air, Salt Water, Steam	One-Piece Construction	ASME BPE	0000000	00000
3"	3.58"	2 3/8"	60 psi @ 70° F	Not Rated	200°	Water, Acetic Acid, Air, Alcohol-Based Solvents, Compressed Air, Salt Water, Steam	One-Piece Construction	ASME BPE	0000000	000000
4"	4.68"	3 1/4"	30 psi @ 70° F	Not Rated	200°	Water, Acetic Acid, Air, Alcohol-Based Solvents, Compressed Air, Salt Water, Steam	One-Piece Construction	ASME BPE	0000000	000000
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 Certified, USP Class VI	0000000	000000
2"	2.52"	1 9/16"	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 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 Certified, USP Class VI	0000000	000000
4"	4.68"	1 1/8"	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 Certified, USP Class VI	0000000	000000

High-Vacuum Flanged Sights

Add a window to your high-vacuum system. With a pane of borosilicate glass sealed inside a high-vacuum CF flange, these sights bolt onto vacuum chambers, tee fittings, and manifolds. Use a copper gasket (sold separately) to create a seal. Not for use with pressure. To illuminate dark interiors, attach an optional light to the flange with set screws.

Sights

					Window			Bolt Holes
Trade Number	Flange OD	For Tube OD	High Vacuum Connection Type	Max. Vacuum	Dia.	Material	Bolt Circle Dia.	No. of	Dia.	Max. Temp., °F		Each
304 Stainless Steel
16	1 21/64"	3/4"	CF	1 × 10 ^-11 torr @ 72° F	5/8"	Glass	1 1/16"	6	11/64"	750°	0000000	0000000
40	2 3/4"	1 1/2"	CF	1 × 10 ^-11 torr @ 72° F	1 3/8"	Glass	2 5/16"	6	17/64"	750°	0000000	000000
63	4 1/2"	2 1/2"	CF	1 × 10 ^-11 torr @ 72° F	2 5/8"	Glass	3 5/8"	8	21/64"	750°	0000000	000000
100	6"	4"	CF	1 × 10 ^-11 torr @ 72° F	3 7/8"	Glass	5 1/8"	16	21/64"	750°	0000000	000000

Gaskets

Gasket

For Flange OD	For Tube OD	Gasket Material	Specifications Met		Each
1 21/64"	3/4"	Copper	ASTM F68	0000000	00000
2 3/4"	1 1/2"	Copper	ASTM F68	0000000	0000
4 1/2"	2 1/2"	Copper	ASTM F68	0000000	0000
6"	4"	Copper	ASTM F68	0000000	0000

Optional Lights

Built-In LED Bulbs
For Flange Trade Number	For Flange OD	ID	Housing Material	Mount Type	Mounting Hardware Included		Each
40	2 3/4"	1 1/8"	Anodized Aluminum	Set Screw	Yes	0000000	0000000
63	4 1/2"	2 13/32"	Anodized Aluminum	Set Screw	Yes	0000000	000000
100	6"	3 9/16"	Anodized Aluminum	Set Screw	Yes	0000000	000000

High-Vacuum Sights for Quick-Clamp Fittings

Sight Shown Assembled with Tube Fitting, Ring, and Clamp (All Sold Separately)

Designed with quick-clamp (KF) connections, these sights connect to a port on a high-vacuum chamber, so you can monitor what's happening inside. A sleeve seals the glass window to the body of the sight to prevent leaks. To connect to your chamber, you'll need a clamp and a ring (sold separately). Not for use in pressure applications.

Sights

Sight

					Window
Trade Number	For Flange OD	For Tube OD	High Vacuum Connection Type	Max. Vacuum	Dia.	Material	Max. Temp., °F		Each
304 Stainless Steel
16	1.18"	3/4"	ISO-KF	1 × 10 ^-9 torr @ 72° F	5/8"	Glass	390°	0000000	0000000
25	1.57"	1"	ISO-KF	1 × 10 ^-9 torr @ 72° F	7/8"	Glass	390°	0000000	000000
40	2.16"	1 1/2"	ISO-KF	1 × 10 ^-9 torr @ 72° F	7/8"	Glass	390°	0000000	000000
50	2.95"	2"	ISO-KF	1 × 10 ^-9 torr @ 72° F	1 3/8"	Glass	390°	0000000	000000

Clamps

Trade Number	For Flange OD	For Tube OD	Material	Max. Vacuum	High Vacuum Connection Type		Each
10, 16	1.18"	1/2", 3/4"	Aluminum	1 × 10^-7 torr @ 72° F	ISO-KF	00000000	00000
25	1.57"	1"	Aluminum	1 × 10^-7 torr @ 72° F	ISO-KF	0000000	00000
40	2.16"	1 1/2"	Aluminum	1 × 10^-7 torr @ 72° F	ISO-KF	0000000	00000
50	2.95"	2"	Aluminum	1 × 10^-7 torr @ 72° F	ISO-KF	0000000	00000

Rings

Trade Number	For Flange OD	For Tube OD	Inner Ring Material	Max. Vacuum	High Vacuum Connection Type		Each
16	1.18"	3/4"	304 Stainless Steel	1 × 10^-7 torr @ 72° F	ISO-KF	00000000	00000
25	1.57"	1"	304 Stainless Steel	1 × 10^-7 torr @ 72° F	ISO-KF	0000000	0000
40	2.16"	1 1/2"	304 Stainless Steel	1 × 10^-7 torr @ 72° F	ISO-KF	0000000	00000
50	2.95"	2"	304 Stainless Steel	1 × 10^-7 torr @ 72° F	ISO-KF	0000000	00000

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

Monitor liquid movement, color, and clarity in tube systems—this sight has barbed fittings that slide into soft plastic and rubber tubing. It has a clear body and a ball 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		Each
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	0000000	000000

Flow Sights for High Vacuum

Peer through the glass on these flow sights to see what’s happening in your high-vacuum line. These flow sights are often used to check the progress of fluids, gases, or probes entering the vacuum system, or to confirm that contaminants have been pumped out. They can also be used as an insulator or low-voltage electrical break on high-vacuum tube lines. The body is 304 stainless steel, which emits less gas into a vacuum than other types of metal and does not corrode in water. The glass tube and stainless steel body are fused together to eliminate leaks. These flow sights are also known as glass tube adapters. Not for use in pressure applications.

Bolt flow sights with a flanged connection to another flange with a copper gasket (sold separately) in between. These flanges are also known as CF, Conflat, and UHV connections.

Join flow sights with quick-clamp connections to your line with a clamp and a ring (sold separately). They are also known as KF, QF, and NW fittings.

Flow sights with a tube connection can be capped, plugged, or twisted onto a line with quick-clamp adapters (sold separately).

Flanged

					Window
For Tube OD	Flange OD	Trade Number	High Vacuum Connection Type	Temp. Range, °F	Dia.	Lg.	End-to-End Lg.	Ht.	Max. Vacuum		Each
304 Stainless Steel Body
3/4"	1 21/64"	16	CF	-320° to 750°	3/4"	1"	4 3/8"	1 21/64"	1 × 10 ^-10 torr @ 72° F	0000000	0000000
3/4"	1 21/64"	16	CF	-320° to 750°	3/4"	6"	9 3/8"	1 21/64"	1 × 10 ^-10 torr @ 72° F	0000000	000000
1 1/2"	2 3/4"	40	CF	-320° to 750°	1 1/2"	1"	4 3/8"	2 3/4"	1 × 10 ^-10 torr @ 72° F	0000000	000000
1 1/2"	2 3/4"	40	CF	-320° to 750°	1 1/2"	6"	9 3/8"	2 3/4"	1 × 10 ^-10 torr @ 72° F	0000000	000000
2 1/2"	4 1/2"	63	CF	-320° to 750°	2 1/2"	1"	5 1/8"	4 1/2"	1 × 10 ^-10 torr @ 72° F	0000000	000000
2 1/2"	4 1/2"	63	CF	-320° to 750°	2 1/2"	6"	10 1/8"	4 1/2"	1 × 10 ^-10 torr @ 72° F	0000000	00000000
4"	6"	100	CF	-320° to 750°	4"	1"	5 1/8"	6"	1 × 10 ^-10 torr @ 72° F	0000000	00000000
4"	6"	100	CF	-320° to 750°	4"	6"	10 1/8"	6"	1 × 10 ^-10 torr @ 72° F	0000000	00000000

Quick Clamp

					Window
For Tube OD	Flange OD	Trade Number	High Vacuum Connection Type	Temp. Range, °F	Dia.	Lg.	End-to-End Lg.	Ht.	Window Material	Max. Vacuum		Each
304 Stainless Steel Body
3/4"	1.18"	16	ISO-KF	0° to 390°	3/4"	1"	4 3/8"	1 3/16"	Glass	1 × 10 ^-8 torr @ 72° F	0000000	0000000
3/4"	1.18"	16	ISO-KF	0° to 390°	3/4"	6"	9 3/8"	1 3/16"	Glass	1 × 10 ^-8 torr @ 72° F	0000000	000000
1"	1.57"	25	ISO-KF	0° to 390°	1"	1"	4 3/8"	1 9/16"	Glass	1 × 10 ^-8 torr @ 72° F	0000000	000000
1"	1.57"	25	ISO-KF	0° to 390°	1"	6"	9 3/8"	1 9/16"	Glass	1 × 10 ^-8 torr @ 72° F	0000000	000000
1 1/2"	2.16"	40	ISO-KF	0° to 390°	1 1/2"	1"	4 3/8"	2 3/16"	Glass	1 × 10 ^-8 torr @ 72° F	0000000	000000
1 1/2"	2.16"	40	ISO-KF	0° to 390°	1 1/2"	6"	9 3/8"	2 3/16"	Glass	1 × 10 ^-8 torr @ 72° F	0000000	000000
2"	2.95"	50	ISO-KF	0° to 390°	2"	1"	5 1/8"	3"	Glass	1 × 10 ^-8 torr @ 72° F	0000000	000000
2"	2.95"	50	ISO-KF	0° to 390°	2"	6"	10 1/8"	3"	Glass	1 × 10 ^-8 torr @ 72° F	0000000	000000

Quick Clamp × Tube

						Window
For Tube OD	Tube OD	Trade Number	Flange OD	High Vacuum Connection Type	Max. Temp., °F	Dia.	Lg.	End-to-End Lg.	Ht.	Max. Vacuum		Each
304 Stainless Steel Body
3/4"	3/4"	16	1.18"	ISO-KF	300°	1/2"	3"	4 7/8"	1 3/16"	1 × 10 ^-8 torr @ 72° F	000000	000000
3/4"	3/4"	16	1.18"	ISO-KF	300°	3/4"	3"	4 7/8"	1 3/16"	1 × 10 ^-8 torr @ 72° F	0000000	00000
1"	1"	25	1.57"	ISO-KF	300°	1"	3"	4 7/8"	1 9/16"	1 × 10 ^-8 torr @ 72° F	0000000	00000
1 1/2"	1 1/2"	40	2.16"	ISO-KF	300°	1 1/2"	3"	4 7/8"	2 3/16"	1 × 10 ^-8 torr @ 72° F	0000000	000000

Gaskets

Gasket

For Tube OD	For Flange OD	Gasket Material	Specifications Met		Each
3/4"	1 21/64"	Copper	ASTM F68	0000000	00000
1 1/2"	2 3/4"	Copper	ASTM F68	0000000	0000
2 1/2"	4 1/2"	Copper	ASTM F68	0000000	0000
4"	6"	Copper	ASTM F68	0000000	0000

Clamps

Clamp with Wing Nut

with Wing Nut
For Tube OD	For Flange OD	Trade Number	High Vacuum Connection Type	Material	Nut Material	Temp. Range, °F	Max. Vacuum	Specifications Met		Each
1/2"	1.18"	10	ISO-KF	Aluminum	Zinc Alloy	0° to 300°	1 × 10 ^-7 torr @ 72° F	ISO 2861	00000000	00000
1/2", 3/4"	1.18"	10, 16	ISO-KF	Aluminum	Zinc Alloy	0° to 300°	1 × 10 ^-7 torr @ 72° F	ISO 2861	00000000	0000
3/4"	1.18"	16	ISO-KF	Aluminum	Zinc Alloy	0° to 300°	1 × 10 ^-7 torr @ 72° F	ISO 2861	00000000	0000
1"	1.57"	25	ISO-KF	Aluminum	Zinc Alloy	0° to 300°	1 × 10 ^-7 torr @ 72° F	ISO 2861	0000000	00000
1 1/2"	2.16"	40	ISO-KF	Aluminum	Zinc Alloy	0° to 300°	1 × 10 ^-7 torr @ 72° F	ISO 2861	0000000	00000
2"	2.95"	50	ISO-KF	Aluminum	Zinc Alloy	0° to 300°	1 × 10 ^-7 torr @ 72° F	ISO 2861	0000000	00000

Rings

Ring

				Material
For Tube OD	For Flange OD	Trade Number	High Vacuum Connection Type	O-Ring	Inner Ring	Temp. Range, °F	Max. Vacuum	Specifications Met		Each
3/4"	1.18"	16	ISO-KF	Fluoroelastomer Rubber	304 Stainless Steel	0° to 300°	1 × 10 ^-7 torr @ 72° F	ISO 2861	00000000	00000
1"	1.57"	25	ISO-KF	Fluoroelastomer Rubber	304 Stainless Steel	0° to 300°	1 × 10 ^-7 torr @ 72° F	ISO 2861	0000000	0000
1 1/2"	2.16"	40	ISO-KF	Fluoroelastomer Rubber	304 Stainless Steel	0° to 300°	1 × 10 ^-7 torr @ 72° F	ISO 2861	0000000	00000
2"	2.95"	50	ISO-KF	Fluoroelastomer Rubber	304 Stainless Steel	0° to 300°	1 × 10 ^-7 torr @ 72° F	ISO 2861	0000000	00000

Straight Adapters, Quick Connect × Quick Clamp

Straight Adapter, Quick Connect × Quick Clamp

	Quick Clamp Tube Connection
For Tube OD (Quick Connect)	For Tube OD	Flange OD	Trade Number	High Vacuum Connection Type	Wall Thick.	Material	O-Ring Material	Temp. Range, °F	Max. Vacuum		Each
3/4"	1"	1.57"	25	ISO-KF	0.055"	304 Stainless Steel	Buna-N Rubber	0° to 175°	1 × 10 ^-8 torr @ 72° F	0000000	000000
1"	1"	1.57"	25	ISO-KF	0.055"	304 Stainless Steel	Buna-N Rubber	0° to 175°	1 × 10 ^-8 torr @ 72° F	0000000	000000
1 1/2"	1 1/2"	2.16"	40	ISO-KF	0.055"	304 Stainless Steel	Buna-N Rubber	0° to 175°	1 × 10 ^-8 torr @ 72° F	0000000	000000

Straight Connectors, Quick Connect

Straight Connector, Quick Connect

For Tube OD	Wall Thick.	Material	O-Ring Material	Temp. Range, °F	Max. Vacuum		Each
1/2"	0.078"	304 Stainless Steel	Viton® Fluoroelastomer Rubber	0° to 175°	1 × 10 ^-8 torr @ 72° F	0000000	0000000
3/4"	0.212"	304 Stainless Steel	Viton® Fluoroelastomer Rubber	0° to 175°	1 × 10 ^-8 torr @ 72° F	0000000	000000
1"	0.18"	304 Stainless Steel	Viton® Fluoroelastomer Rubber	0° to 175°	1 × 10 ^-8 torr @ 72° F	0000000	000000
1 1/2"	0.242"	304 Stainless Steel	Viton® Fluoroelastomer Rubber	0° to 175°	1 × 10 ^-8 torr @ 72° F	0000000	000000

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Sights for Quick-Clamp Sanitary Tube Fittings

High-Vacuum Flanged Sights

High-Vacuum Sights for Quick-Clamp Fittings

Flow Sights with Barbed Fittingsfor Water, Oil, Air, and Inert Gas

Flow Sights for High Vacuum

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