NPT Sight Glass Windows
  • NPT – ISO standard male tapered threaded sight glass
  • Exhibits no outgassing or contamination of most systems*
  • Long working life
  • No maintenance required
  • Tested to high safety factor to insure safety & reliability
  • Exceeds all industry and MIL standards
  • Engineered, Manufactured and tested at the Rayotek U.S. facility
  • Ultra-High Pressure (UHP) tested to 20,000PSI or higher available


NPT Sight Windows, made to ISO 7-1:1994 standards, are a low cost solution for viewing and observation ports for fluid, flame and gas viewing, indicators and sensors. Rayotek NPT Sight Windows utilize glass, sapphire and other transparent materials sealed into a corrosion resistant metal housing to create a hermetically sealed unibody Sight Glass.

Rayotek NPT Sight Windows are exceptionally robust in extreme thermal, chemical, mechanical and pressure environments. They also perform exceptionally in ultra-high vacuum, high purity, cleanroom rated systems.

Applications:

  • High pressure tanks
  • Liquid level view ports
  • Hydraulic level indicators
  • Flame & explosion observation ports for furnace, heater & hazardous systems
  • Supercritical & petroleum research systems
  • All classes of refrigerant systems, including CO2-based R744
  • Sanitary & FDA applications for pharmaceutical & food processing
  • Simple lighting windows for deep sea, ultra high pressure & vacuum systems


Rayotek Sight Windows can reliably meet and exceed the requirements of many applications from industrial to research. The selection of window, housing material and sealing method will help optimize the best sight window configuration for your application.

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Footnotes:
† Alternative materials are available upon request including, but not limited to:
        Housing: duplex, aluminum, Monel, Inconel, plastics and alumina
        Window: borosilicate (Pyrex®), diamond, Zinc Selenide, fused silica, germanium, MgF2, silicon and YAG

* For systems where purity & cleanliness are critical, Rayotek recommends testing the Sight Window for specific chemical compatibility.
    Call for information.

** Typical leak rate is 10-8 bar-CC/sec. for air at 22C. Actual leak rate TBD based on window size and maximum operating temperature.
    Call for information.



(All NPT's by Size, sorted by configuration)

1/4" NPT

Nominal Size Pressure Rating* (psi/bar) Window Material Housing Material Seal Type Clear Aperture In. (mm) Min. Operating Temperature ˚C (˚F) Max. Operating Temperature ˚C (˚F) Internal (IP), External (EP) or Vacuum (VAC) Part Number Additional Info
1/4 1000 (69) Soda Lime 316 Stainless Fused 0.39 (9.9) -60 (-51) 300 (572) EP, IP, VAC 101001 In Stock
1/4 4000 (276) Soda Lime 316 Stainless Fused 0.39 (9.9) -60 (-51) 300 (572) EP, IP, VAC 101012 In Stock
1/4 1000 (69) Sapphire 316 Stainless Bonded 0.31 (7.9) -70 (-94) 200 (392) EP, VAC 101023 Build To Order
1/4 1000 (69) Sapphire 316 Stainless Bonded 0.31 (7.9) -70 (-94) 200 (392) IP 101034 In Stock
1/4 4000 (276) Sapphire 316 Stainless Bonded 0.26 (6.6) -70 (-94) 200 (392) EP, VAC 101045 Build To Order
1/4 4000 (276) Sapphire 316 Stainless Bonded 0.26 -70 (-94) 200 (392) IP 101056 In Stock

3/8" NPT

Nominal Size Pressure Rating* (psi/bar) Window Material Housing Material Seal Type Clear Aperture In. (mm) Min. Operating Temperature ˚C (˚F) Max. Operating Temperature ˚C (˚F) Internal (IP), External (EP) or Vacuum (VAC) Part Number Additional Info
3/8 1000 (69) Soda Lime 316 Stainless Fused 0.48 (12.2) -60 (-51) 300 (572) EP, IP, VAC 101002 Build To Order
3/8 4000 (276) Soda Lime 316 Stainless Fused 0.48 (12.2) -60 (-51) 300 (572) EP, IP, VAC 101013 In Stock
3/8 1000 (69) Sapphire 316 Stainless Bonded 0.40 (10.2) -70 (-94) 200 (392) EP, VAC 101024 In Stock
3/8 1000 (69) Sapphire 316 Stainless Bonded 0.40 (10.2) -70 (-94) 200 (392) IP 101035 In Stock
3/8 4000 (276) Sapphire 316 Stainless Bonded 0.33 -70 (-94) 200 (392) EP, VAC 101046 Build To Order
3/8 4000 (276) Sapphire 316 Stainless Bonded 0.33 -70 (-94) 200 (392) IP 101057 In Stock

1/2" NPT

Nominal Size Pressure Rating* (psi/bar) Window Material Housing Material Seal Type Clear Aperture In. (mm) Min. Operating Temperature ˚C (˚F) Max. Operating Temperature ˚C (˚F) Internal (IP), External (EP) or Vacuum (VAC) Part Number Additional Info
1/2 1000 (69) Soda Lime 316 Stainless Fused 0.59 (15.0) -60 (-51) 300 (572) EP, IP, VAC 101003 Build To Order
1/2 4000 (276) Soda Lime 316 Stainless Fused 0.46 (15.0) -60 (-51) 300 (572) EP, IP, VAC 101014 In Stock
1/2 1000 (69) Sapphire 316 Stainless Bonded 0.51 (13.0) -70 (-94) 200 (392) EP, VAC 101025 Build To Order
1/2 1000 (69) Sapphire 316 Stainless Bonded 0.51 (13.0) -70 (-94) 200 (392) IP 101036 In Stock
1/2 4000 (276) Sapphire 316 Stainless Bonded 0.34 -70 (-94) 200 (392) EP, VAC 101047 Build To Order
1/2 4000 (276) Sapphire 316 Stainless Bonded 0.34 -70 (-94) 200 (392) IP 101058 In Stock
1/2 150 (10.3) Fused Quartz 316 Stainless Gasketed 0.34 (8.6) -200 (-328) 900 (1652) EP, IP, VAC 101080 Build To Order

3/4" NPT

Nominal Size Pressure Rating* (psi/bar) Window Material Housing Material Seal Type Clear Aperture In. (mm) Min. Operating Temperature ˚C (˚F) Max. Operating Temperature ˚C (˚F) Internal (IP), External (EP) or Vacuum (VAC) Part Number Additional Info
3/4 1000 (69) Soda Lime 316 Stainless Fused 0.81 (20.6) -60 (-51) 300 (572) EP, IP, VAC 101004 Build To Order
3/4 4000 (276) Soda Lime 316 Stainless Fused 0.55 (20.6) -60 (-51) 300 (572) EP, IP, VAC 101015 In Stock
3/4 1000 (69) Sapphire 316 Stainless Bonded 0.73 (18.5) -70 (-94) 200 (392) EP, VAC 101026 Build To Order
3/4 1000 (69) Sapphire 316 Stainless Bonded 0.73 (18.5) -70 (-94) 200 (392) IP 101037 In Stock
3/4 4000 (276) Sapphire 316 Stainless Bonded 0.42 -70 (-94) 200 (392) EP, VAC 101048 Build To Order
3/4 4000 (276) Sapphire 316 Stainless Bonded 0.42 -70 (-94) 200 (392) IP 101059 In Stock
3/4 150 (10.3) Fused Quartz 316 Stainless Gasketed 0.56 (14.2) -200 (-328) 900 (1652) EP, IP, VAC 101081 Build To Order

1" NPT

Nominal Size Pressure Rating* (psi/bar) Window Material Housing Material Seal Type Clear Aperture In. (mm) Min. Operating Temperature ˚C (˚F) Max. Operating Temperature ˚C (˚F) Internal (IP), External (EP) or Vacuum (VAC) Part Number Additional Info
1 1000 (69) Soda Lime 316 Stainless Fused 0.96 (24.4) -60 (-51) 300 (572) EP, IP, VAC 101005 Build To Order
1 4000 (276) Soda Lime 316 Stainless Fused 0.76 (24.4) -60 (-51) 300 (572) EP, IP, VAC 101016 In Stock
1 1000 (69) Sapphire 316 Stainless Bonded 0.88 (22.4) -70 (-94) 200 (392) EP, VAC 101027 Build To Order
1 1000 (69) Sapphire 316 Stainless Bonded 0.88 (22.4) -70 (-94) 200 (392) IP 101038 In Stock
1 4000 (276) Sapphire 316 Stainless Bonded 0.61 -70 (-94) 200 (392) EP, VAC 101049 Build To Order
1 4000 (276) Sapphire 316 Stainless Bonded 0.61 -70 (-94) 200 (392) IP 101060 In Stock
1 150 (10.3) Fused Quartz 316 Stainless Gasketed 0.71 (18.0) -200 (-328) 900 (1652) EP, IP, VAC 101082 Build To Order

1-1/4" NPT

Nominal Size Pressure Rating* (psi/bar) Window Material Housing Material Seal Type Clear Aperture In. (mm) Min. Operating Temperature ˚C (˚F) Max. Operating Temperature ˚C (˚F) Internal (IP), External (EP) or Vacuum (VAC) Part Number Additional Info
1-1/4 1000 (69) Soda Lime 316 Stainless Fused 1.32 (33.5) -60 (-51) 300 (572) EP, IP, VAC 101006 In Stock
1-1/4 4000 (276) Soda Lime 316 Stainless Fused 0.94 (33.5) -60 (-51) 300 (572) EP, IP, VAC 101017 In Stock
1-1/4 1000 (69) Sapphire 316 Stainless Bonded 1.24 (31.5) -70 (-94) 200 (392) EP, VAC 101028 Build To Order
1-1/4 1000 (69) Sapphire 316 Stainless Bonded 1.24 (31.5) -70 (-94) 200 (392) IP 101039 In Stock
1-1/4 4000 (276) Sapphire 316 Stainless Bonded 0.78 -70 (-94) 200 (392) EP, VAC 101050 Build To Order
1-1/4 4000 (276) Sapphire 316 Stainless Bonded 0.78 -70 (-94) 200 (392) IP 101061 In Stock
1-1/4 150 (10.3) Fused Quartz 316 Stainless Gasketed 1.07 (27.2) -200 (-328) 900 (1652) EP, IP, VAC 101083 Build To Order

1-1/2" NPT

Nominal Size Pressure Rating* (psi/bar) Window Material Housing Material Seal Type Clear Aperture In. (mm) Min. Operating Temperature ˚C (˚F) Max. Operating Temperature ˚C (˚F) Internal (IP), External (EP) or Vacuum (VAC) Part Number Additional Info
1-1/2 1000 (69) Soda Lime 316 Stainless Fused 1.47 (37.3) -60 (-51) 300 (572) EP, IP, VAC 101007 Build To Order
1-1/2 4000 (276) Soda Lime 316 Stainless Fused 1.10 (37.3) -60 (-51) 300 (572) EP, IP, VAC 101018 In Stock
1-1/2 1000 (69) Sapphire 316 Stainless Bonded 1.38 (35.1) -70 (-94) 200 (392) EP, VAC 101029 Build To Order
1-1/2 1000 (69) Sapphire 316 Stainless Bonded 1.38 (35.1) -70 (-94) 200 (392) IP 101040 In Stock
1-1/2 4000 (276) Sapphire 316 Stainless Bonded 0.93 -70 (-94) 200 (392) EP, VAC 101051 Build To Order
1-1/2 4000 (276) Sapphire 316 Stainless Bonded 0.93 -70 (-94) 200 (392) IP 101062 In Stock
1-1/2 150 (10.3) Fused Quartz 316 Stainless Gasketed 1.22 (31.0) -200 (-328) 900 (1652) EP, IP, VAC 101084 Build To Order

2" NPT

Nominal Size Pressure Rating* (psi/bar) Window Material Housing Material Seal Type Clear Aperture In. (mm) Min. Operating Temperature ˚C (˚F) Max. Operating Temperature ˚C (˚F) Internal (IP), External (EP) or Vacuum (VAC) Part Number Additional Info
2 1000 (69) Soda Lime 316 Stainless Fused 1.76 (44.7) -60 (-51) 300 (572) EP, IP, VAC 101008 In Stock
2 4000 (276) Soda Lime 316 Stainless Fused 1.42 (44.7) -60 (-51) 300 (572) EP, IP, VAC 101019 In Stock
2 1000 (69) Sapphire 316 Stainless Bonded 1.66 (42.2) -70 (-94) 200 (392) EP, VAC 101030 Build To Order
2 1000 (69) Sapphire 316 Stainless Bonded 1.66 (42.2) -70 (-94) 200 (392) IP 101041 In Stock
2 4000 (276) Sapphire 316 Stainless Bonded 1.22 -70 (-94) 200 (392) EP, VAC 101052 Build To Order
2 4000 (276) Sapphire 316 Stainless Bonded 1.22 -70 (-94) 200 (392) IP 101063 In Stock
2 150 (10.3) Fused Quartz 316 Stainless Gasketed 1.51 (38.4) -200 (-328) 900 (1652) EP, IP, VAC 101085 Build To Order

2-1/2" NPT

Nominal Size Pressure Rating* (psi/bar) Window Material Housing Material Seal Type Clear Aperture In. (mm) Min. Operating Temperature ˚C (˚F) Max. Operating Temperature ˚C (˚F) Internal (IP), External (EP) or Vacuum (VAC) Part Number Additional Info
2-1/2 1000 (69) Soda Lime 316 Stainless Fused 2.21 (56.1) -60 (-51) 300 (572) EP, IP, VAC 101009 Build To Order
2-1/2 4000 (276) Soda Lime 316 Stainless Fused 1.88 (56.1) -60 (-51) 300 (572) EP, IP, VAC 101020 Build To Order
2-1/2 1000 (69) Sapphire 316 Stainless Bonded 2.10 (53.3) -70 (-94) 200 (392) EP, VAC 101031 Build To Order
2-1/2 1000 (69) Sapphire 316 Stainless Bonded 2.10 (53.3) -70 (-94) 200 (392) IP 101042 Build To Order
2-1/2 4000 (276) Sapphire 316 Stainless Bonded 1.66 -70 (-94) 200 (392) EP, VAC 101053 Build To Order
2-1/2 4000 (276) Sapphire 316 Stainless Bonded 1.66 -70 (-94) 200 (392) IP 101064 Build To Order
2-1/2 150 (10.3) Fused Quartz 316 Stainless Gasketed 1.96 (49.8) -200 (-328) 900 (1652) EP, IP, VAC 101086 Build To Order

3" NPT

Nominal Size Pressure Rating* (psi/bar) Window Material Housing Material Seal Type Clear Aperture In. (mm) Min. Operating Temperature ˚C (˚F) Max. Operating Temperature ˚C (˚F) Internal (IP), External (EP) or Vacuum (VAC) Part Number Additional Info
3 1000 (69) Soda Lime 316 Stainless Fused 2.50 (63.5) -60 (-51) 300 (572) EP, IP, VAC 101010 Build To Order
3 4000 (276) Soda Lime 316 Stainless Fused 2.13 (63.5) -60 (-51) 300 (572) EP, IP, VAC 101021 Build To Order
3 1000 (69) Sapphire 316 Stainless Bonded 2.38 (60.5) -70 (-94) 200 (392) EP, VAC 101032 Build To Order
3 1000 (69) Sapphire 316 Stainless Bonded 2.38 (60.5) -70 (-94) 200 (392) IP 101043 Build To Order
3 4000 (276) Sapphire 316 Stainless Bonded 1.89 -70 (-94) 200 (392) EP, VAC 101054 Build To Order
3 4000 (276) Sapphire 316 Stainless Bonded 1.89 -70 (-94) 200 (392) IP 101065 Build To Order
3 150 (10.3) Fused Quartz 316 Stainless Gasketed 2.00 (50.8) -200 (-328) 900 (1652) EP, IP, VAC 101087 Build To Order

4" NPT

Nominal Size Pressure Rating* (psi/bar) Window Material Housing Material Seal Type Clear Aperture In. (mm) Min. Operating Temperature ˚C (˚F) Max. Operating Temperature ˚C (˚F) Internal (IP), External (EP) or Vacuum (VAC) Part Number Additional Info
4 1000 (69) Soda Lime 316 Stainless Fused 3.09 (78.5) -60 (-51) 300 (572) EP, IP, VAC 101011 Build To Order
4 4000 (276) Soda Lime 316 Stainless Fused 2.890 (78.5) -60 (-51) 300 (572) EP, IP, VAC 101022 Build To Order
4 1000 (69) Sapphire 316 Stainless Bonded 2.94 (74.7) -70 (-94) 200 (392) EP, VAC 101033 Build To Order
4 1000 (69) Sapphire 316 Stainless Bonded 2.94 (74.7) -70 (-94) 200 (392) IP 101044 Build To Order
4 4000 (276) Sapphire 316 Stainless Bonded 2.60 -70 (-94) 200 (392) EP, VAC 101055 Build To Order
4 4000 (276) Sapphire 316 Stainless Bonded 2.60 -70 (-94) 200 (392) IP 101066 Build To Order
4 150 (10.3) Fused Quartz 316 Stainless Gasketed 2.59 (65.8) -200 (-328) 900 (1652) EP, IP, VAC 101088 Build To Order