NPT Sight Glasses

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Sight Glasses

NPT Sight Glasses

NPT sight glasses are typical NPT fittings having NPT male threads, where the window is encased into the metal housing forming a single-piece part. Designed up to 7000 psi pressure, these sight glasses have optical clarity suitable for imaging systems and also for looking at oil levels inside pressure vessels, or checking the color of a refrigerant. These NPT sight glasses transmit a broad spectrum of wavelengths, ranging from near-infrared, visible light, to ultraviolet. Sight glasses with quartz use material GE-124 quartz. It's a pure form of silica commonly used in semiconductor equipment. This quartz has high purity for use in a process in semiconductor reactors.

Encole LLC

NPT-Threaded High Pressure Sight Glass, Quartz Window, 17-4PH Steel Housing

Sight window with NPT threads conforming to ASME B1.20.1. For visual inspection, machine vision, laser sensors, in use with all common hydraulic oils, refrigerants, pharmaceutical processing equipment.This sight glass is an ideal choice for applications requiring no compromises in optical clarity. The window is flat on both sides, and precisely polished to surface quality of 40-20 S-D per MIL-O-13830. Because the window material is quartz, this sight glass can be used in applications requiring extended transmission ranges. Specifically, this window transmits over 50 percent of light from 217 to 3600 nm wavelengths. Quartz window is sealed into the housing with non-outgassing quartz-filled bond forming a single-piece part. This sight glass has a long working life under severe temperature swings and prolonged exposures to UV light.

Aperture Dia.	Thread	Max Operating Temp.	Housing Material	Max Operating Pressure	Window Material	Mfg P/N	Encole P/N	Price
0.35 inch	NPT 3/8	65 C	17-4PH	6170 psi	Quartz	100765	769E701	$ 408.00 each
0.40 inch	NPT 1/2	60 C	17-4PH	6170 psi	Quartz	100766	769E702	$ 426.04 each
0.55 inch	NPT 3/4	55 C	17-4PH	6170 psi	Quartz	100767	769E703	RFQ
0.75 inch	NPT 1	45 C	17-4PH	6170 psi	Quartz	100768	769E704	$ 435.90 each
1.01 inch	NPT 1-1/4	40 C	17-4PH	6170 psi	Quartz	100769	769E705	RFQ
1.22 inch	NPT 1-1/2	40 C	17-4PH	6170 psi	Quartz	100770	769E706	$ 697.58 each
1.61 inch	NPT 2	35 C	17-4PH	6170 psi	Quartz	100771	769E707	RFQ

Metaglas, Herberts Industrieglas GmbH & Co. KG

Fused NPT Sight Glass, Duplex Steel 2205, Sodalime, Full Glass Height

Soda lime glass is fused to a duplex steel 2205 housing, where the glass extends the entire height of the fitting. Glass is flush with both ends of the housing. Sides of the glass are flat and polished to approximately S-D: 80-40, which is an optical finish of a typical window in a building. This optical clarity is suitable for undistorted viewing through the sight glass. For visual inspection, machine vision, optical sensors, in use with all common hydraulic oils, refrigeration, water heaters, and compressed air applications. Connections are NPT or NPTF (Dryseal) threads conforming to ASME B1.20.1.

Aperture Dia.	Thread	Max Operating Temp.	Max Operating Pressure	Housing Material	Window Material	Mfg P/N	Encole P/N	Price
5 mm	NPT 1/4	150 C	100 bar	Duplex 2205	Soda lime	Met-62-025S	774E1601	$ 214.08 each
5 mm	NPTF 1/4	150 C	100 bar	Duplex 2205	Soda lime	Met-62F-025S	774E1602	$ 219.80 each
7 mm	NPT 3/8	150 C	100 bar	Duplex 2205	Soda lime	Met-62-038S	774E1603	$ 231.05 each
7 mm	NPTF 3/8	150 C	100 bar	Duplex 2205	Soda lime	Met-62F-038S	774E1604	$ 254.60 each
11 mm	NPT 1/2	150 C	100 bar	Duplex 2205	Soda lime	Met-62-050S	774E1605	$ 248.12 each
11 mm	NPTF 1/2	150 C	100 bar	Duplex 2205	Soda lime	Met-62F-050S	774E1606	$ 268.90 each
19 mm	NPT 3/4	150 C	100 bar	Duplex 2205	Soda lime	Met-62-075S	774E1607	$ 262.12 each
19 mm	NPTF 3/4	150 C	100 bar	Duplex 2205	Soda lime	Met-62F-075S	774E1608	$ 290.52 each
17 mm	NPT 1	150 C	100 bar	Duplex 2205	Soda lime	Met-62-100S	774E1609	$ 283.15 each
17 mm	NPTF 1	150 C	100 bar	Duplex 2205	Soda lime	Met-62F-100S	774E16010	$ 302.90 each
22 mm	NPT 1-1/4	150 C	100 bar	Duplex 2205	Soda lime	Met-62-125S	774E16011	$ 288.05 each
22 mm	NPTF 1-1/4	150 C	100 bar	Duplex 2205	Soda lime	Met-62F-125S	774E16012	$ 315.64 each
25 mm	NPT 1-1/2	150 C	100 bar	Duplex 2205	Soda lime	Met-62-150S	774E16013	$ 299.25 each
25 mm	NPTF 1-1/2	150 C	100 bar	Duplex 2205	Soda lime	Met-62F-150S	774E16014	$ 342.50 each
35 mm	NPT 2	150 C	100 bar	Duplex 2205	Soda lime	Met-62-200S	774E16015	$ 381.23 each
35 mm	NPTF 2	150 C	100 bar	Duplex 2205	Soda lime	Met-62F-200S	774E16016	$ 429.80 each

Oil-Rite Corporation

Stainless Steel Gasketed Glass Sight with NPT Threads

303 Stainless Steel Gasketed Glass Sight for visual observation of liquid levels and their condition. This sight glass is typically used in any application where oil or fluid inspection is essential. The housing is a 303 Stainless Steel fitting with U.S. standard NPT threads conforming to ASME B1.20.1. Use traditional installation tools and Teflon tape or pipe sealant. This sight has Buna-N internal seal with good chemical compatibility with Petroleum oils and fluids; Cold Water; Silicone greases and oils; Dibasic Acid Ester (Diester) based lubricants (MIL-L-7808); Ethylene glycol base fluids (Hydrolubes). Not Recommended for: Halogenated hydrocarbons (carbon tetrachloride, trichloroethylene); Nitro hydrocarbons (nitrobenzene, aniline); Phosphate ester hydraulic fluids (Skydrol, Fyrquel, Pydraul); Ketones (MEK, acetone); Strong Acids Ozone; Automotive brake fluid.

Aperture Dia.	Thread	Max Operating Pressure	Max Operating Temp.	Housing Material	Window Material	Mfg P/N	Encole P/N	Price
0.312 inch	NPT 1/4	125 psi	225 F	AISI 303	Soda lime	B4763-01B	776E801	$ 59.26 per package of 2
0.470 inch	NPT 3/8	125 psi	225 F	AISI 303	Soda lime	B4763-02B	776E802	$ 65.32 per package of 2
0.594 inch	NPT 1/2	125 psi	225 F	AISI 303	Soda lime	B4763-03B	776E803	$ 77.32 per package of 2
0.781 inch	NPT 3/4	125 psi	225 F	AISI 303	Soda lime	B4763-04B	776E804	$ 85.32 per package of 2
1.000 inch	NPT 1	100 psi	225 F	AISI 303	Soda lime	B4763-05B	776E805	$ 93.78 each
1.531 inch	NPT 1-1/4	75 psi	225 F	AISI 303	Soda lime	B4763-06B	776E806	$ 61.90 each
1.593 inch	NPT 1-1/2	50 psi	225 F	AISI 303	Soda lime	B4763-07B	776E807	$ 72.67 each
1.970 inch	NPT 2	50 psi	225 F	AISI 303	Soda lime	B4763-08B	776E808	$ 86.75 each

Metaglas, Herberts Industrieglas GmbH & Co. KG

NPT-Threaded Fused Sight Glass, Borosilicate Windows

Metaglas fused sight glass for use with all common hydraulic oils, refrigeration, water heaters, and compressed air applications. Fusing glass to metal creates a strong, hermetically sealed single-piece part. The advantage of this construction is high strength of the glass, which ensures safety of operation, even during cycling operating temperatures common with equipment starts and stops. The part is easy to install and has a long working life without maintenance. This sight window has NPT threads conforming to ASME B1.20.1. Note: The image of the objects behind the glass may be distorted closer to the edges of the aperture diameter as the glass is slightly concave. This is due to the fusing process.

Aperture Dia.	Thread	Housing Material	Max Operating Temp.	Max Operating Pressure	Window Material	Mfg P/N	Encole P/N	Price
9 mm	NPT 1/4	Hastelloy C-22	300 C	100 bar	Borosilicate	Met-61-025H	770E3601	$ 287.54 each
9 mm	NPTF 1/4	Hastelloy C-22	300 C	100 bar	Borosilicate	Met-61-F-025H	770E3602	$ 352.60 each
10 mm	NPT 3/8	Hastelloy C-22	300 C	100 bar	Borosilicate	Met-61-038H	770E3603	$ 333.95 each
10 mm	NPTF 3/8	Hastelloy C-22	300 C	100 bar	Borosilicate	Met-61-F-038H	770E3604	$ 375.60 each
14 mm	NPT 1/2	Hastelloy C-22	300 C	100 bar	Borosilicate	Met-61-050H	770E3605	$ 378.50 each
14 mm	NPTF 1/2	Hastelloy C-22	300 C	100 bar	Borosilicate	Met-61-F-050H	770E3606	$ 415.25 each
18 mm	NPT 3/4	Hastelloy C-22	300 C	100 bar	Borosilicate	Met-61-075H	770E3607	$ 435.90 each
18 mm	NPTF 3/4	Hastelloy C-22	300 C	100 bar	Borosilicate	Met-61-F-075H	770E3608	$ 465.30 each
22 mm	NPT 1	Hastelloy C-22	300 C	100 bar	Borosilicate	Met-61-100H	770E3609	$ 540.00 each
22 mm	NPTF 1	Hastelloy C-22	300 C	100 bar	Borosilicate	Met-61-F-100H	770E36010	$ 587.20 each
25 mm	NPT 1-1/4	Hastelloy C-22	300 C	100 bar	Borosilicate	Met-61-125H	770E36011	$ 622.00 each
25 mm	NPTF 1-1/4	Hastelloy C-22	300 C	100 bar	Borosilicate	Met-61-F-125H	770E36012	$ 675.20 each
30 mm	NPT 1-1/2	Hastelloy C-22	300 C	100 bar	Borosilicate	Met-61-150H	770E36013	$ 712.00 each
30 mm	NPTF 1-1/2	Hastelloy C-22	300 C	100 bar	Borosilicate	Met-61-F-150H	770E36014	$ 768.90 each
37 mm	NPT 2	Hastelloy C-22	300 C	100 bar	Borosilicate	Met-61-200H	770E36015	$ 1370.00 each
37 mm	NPTF 2	Hastelloy C-22	300 C	100 bar	Borosilicate	Met-61-F-200H	770E36016	$ 1410.80 each
55 mm	NPT 3	Hastelloy C-22	300 C	100 bar	Borosilicate	Met-61-300H	770E36017	$ 2321.00 each
55 mm	NPTF 3	Hastelloy C-22	300 C	100 bar	Borosilicate	Met-61-F-300H	770E36018	$ 2482.50 each
9 mm	NPT 1/4	Duplex 2205	280 C	100 bar	Borosilicate	Met-61-025S	770E36019	$ 181.27 each
9 mm	NPTF 1/4	Duplex 2205	280 C	100 bar	Borosilicate	Met-61-F-025S	770E36020	$ 187.90 each
10 mm	NPT 3/8	Duplex 2205	280 C	100 bar	Borosilicate	Met-61-038S	770E36021	$ 189.55 each
10 mm	NPTF 3/8	Duplex 2205	280 C	100 bar	Borosilicate	Met-61-F-038S	770E36022	$ 195.60 each
14 mm	NPT 1/2	Duplex 2205	280 C	100 bar	Borosilicate	Met-61-050S	770E36023	$ 198.32 each
14 mm	NPTF 1/2	Duplex 2205	280 C	100 bar	Borosilicate	Met-61-F-050S	770E36024	$ 216.27 each
18 mm	NPT 3/4	Duplex 2205	280 C	100 bar	Borosilicate	Met-61-075S	770E36025	$ 209.24 each
18 mm	NPTF 3/4	Duplex 2205	280 C	100 bar	Borosilicate	Met-61-F-075S	770E36026	$ 231.50 each
22 mm	NPT 1	Duplex 2205	280 C	100 bar	Borosilicate	Met-61-100S	770E36027	$ 218.53 each
22 mm	NPTF 1	Duplex 2205	280 C	100 bar	Borosilicate	Met-61-F-100S	770E36028	$ 242.80 each
25 mm	NPT 1-1/4	Duplex 2205	280 C	100 bar	Borosilicate	Met-61-125S	770E36029	$ 288.89 each
25 mm	NPTF 1-1/4	Duplex 2205	280 C	100 bar	Borosilicate	Met-61-F-125S	770E36030	$ 297.60 each
30 mm	NPT 1-1/2	Duplex 2205	280 C	100 bar	Borosilicate	Met-61-150S	770E36031	$ 291.08 each
30 mm	NPTF 1-1/2	Duplex 2205	280 C	100 bar	Borosilicate	Met-61-F-150S	770E36032	$ 309.70 each
37 mm	NPT 2	Duplex 2205	280 C	100 bar	Borosilicate	Met-61-200S	770E36033	$ 386.59 each
37 mm	NPTF 2	Duplex 2205	280 C	100 bar	Borosilicate	Met-61-F-200S	770E36034	$ 398.65 each
55 mm	NPT 3	Duplex 2205	280 C	100 bar	Borosilicate	Met-61-300S	770E36035	$ 496.94 each
55 mm	NPTF 3	Duplex 2205	280 C	100 bar	Borosilicate	Met-61-F-300S	770E36036	$ 532.80 each

Oil-Rite Corporation

Low Cost Fused NPT-Threaded Sight Glass, Zinc-Plated Carbon Steel

Sodalime glass is fused to a plain carbon steel body which is Zinc-plated for added corrosion resistance. This sight glass can be threaded directly into a pipe, or a threaded boss welded to a pipe. This sight glass is an ideal budget choice for visual observation of liquid levels and their colors, present or absence of refrigerant, oil levels in a compressor. Applications include hydraulic systems with mineral oils, diesel, and other common liquids where low cost is required. Not suitable for cycling high temperature, high pressure or aggressively corrosive applications.

Aperture Dia.	Thread	Max Operating Temp.	Max Operating Pressure	Housing Material	Window Material	Mfg P/N	Encole P/N	Price
0.340 inch	NPT 1/4	130 F	125 psi	Carbon Steel Zinc-Plated	Soda lime	A2890-1	775E801	$ 53.25 per package of 3
0.560 inch	NPT 1/2	130 F	125 psi	Carbon Steel Zinc-Plated	Soda lime	A2890-3	775E802	$ 68.90 per package of 3
0.940 inch	NPT 1	130 F	125 psi	Carbon Steel Zinc-Plated	Soda lime	A2890-5	775E803	$ 58.79 per package of 2
1.190 inch	NPT 1-1/4	130 F	125 psi	Carbon Steel Zinc-Plated	Soda lime	A2890-6	775E804	$ 75.45 per package of 2
1.440 inch	NPT 1-1/2	130 F	125 psi	Carbon Steel Zinc-Plated	Soda lime	A2890-7	775E805	$ 31.90 each
1.880 inch	NPT 2	130 F	125 psi	Carbon Steel Zinc-Plated	Soda lime	A2890-8	775E806	$ 38.75 each
0.440 inch	NPTF 3/8	130 F	125 psi	Carbon Steel Zinc-Plated	Soda lime	A2890-2	775E807	$ 68.80 per package of 2
0.750 inch	NPTF 3/4	130 F	125 psi	Carbon Steel Zinc-Plated	Soda lime	A2890-4	775E808	$ 74.24 per package of 2

Oil-Rite Corporation

Reflector Sight Glass in Stainless Steel, Gasketed, NPT Threads

Reflector behind the glass helps see oil levels, presence of liquids, color, quality of a fluid. 303 Stainless Steel Gasketed Glass Sight for visual observation of liquid levels and their condition. These sight glasses are typically used in any application where oil or fluid inspection is essential. The housing is a 303 Stainless Steel fitting with U.S. standard NPT threads conforming to ASME B1.20.1. Use traditional installation tools and Teflon tape or pipe sealant. These sight glasses have a Buna-N internal seal for good chemical compatibility with Petroleum oils and fluids; Cold Water; Silicone greases and oils; Dibasic Acid Ester (Diester) based lubricants (MIL-L-7808); Ethylene glycol base fluids (Hydrolubes). Not Recommended for: Halogenated hydrocarbons (carbon tetrachloride, trichloroethylene); Nitro hydrocarbons (nitrobenzene, aniline); Phosphate ester hydraulic fluids (Skydrol, Fyrquel, Pydraul); Ketones (MEK, acetone); Strong Acids Ozone; Automotive brake fluid.

Aperture Dia.	Thread	Max Operating Pressure	Max Operating Temp.	Housing Material	Window Material	Mfg P/N	Encole P/N	Price
0.470 inch	NPT 3/8	125 psi	225 F	AISI 303	Soda lime	B4763-12B	777E701	$ 84.75 per package of 2
0.594 inch	NPT 1/2	125 psi	225 F	AISI 303	Soda lime	B4763-13B	777E702	$ 91.40 per package of 2
0.781 inch	NPT 3/4	125 psi	225 F	AISI 303	Soda lime	B4763-14B	777E703	$ 98.75 per package of 2
1.000 inch	NPT 1	100 psi	225 F	AISI 303	Soda lime	B4763-15B	777E704	$ 113.25 per package of 2
1.531 inch	NPT 1-1/4	75 psi	225 F	AISI 303	Soda lime	B4763-16B	777E705	$ 68.75 each
1.593 inch	NPT 1-1/2	50 psi	225 F	AISI 303	Soda lime	B4763-17B	777E706	$ 79.80 each
1.970 inch	NPT 2	50 psi	225 F	AISI 303	Soda lime	B4763-18B	777E707	$ 91.25 each

Encole LLC

Sight Glass Quartz, Stainless, NPT Size 1/2 inch

Optically clear sight glass for visual observation of oil levels, imaging systems or laser sensors. The quartz window has optical finish of 60-40 S-D, suitable for distortion-free and clear light transmission. This is a single piece sight glass where the window is bonded to the housing, forming an inseparable assembly. The advantage of this construction is vibration resistant sight glass, and long life without having to replace elastomer O-rings. Use traditional installation methods with a Teflon tape of a thread sealant.

Aperture Dia.	Thread	Max Operating Temp.	Housing Material	Max Operating Pressure	Window Material	Mfg P/N	Encole P/N	Price
0.46 inch	NPT 1/2	50 C	316 SS	1870 psi	Quartz	265A1001	1101E101	$ 74.20 each

Encole LLC

High Pressure SIght Glass, NPT 1 inch Threaded, 316 Stainless, Quartz WIndow

Aperture Dia.	Thread	Max Operating Temp.	Housing Material	Max Operating Pressure	Window Material	Mfg P/N	Encole P/N	Price
0.75 inch	NPT 1	48 C	316 SS	3400 psi	Quartz	324A1003	1102E101	$ 98.25 each