A High Pressure Sight Glass is an optical device engineered to withstand extreme conditions while allowing direct visual inspection of fluid flow inside closed systems. These include pressurized tanks, steam boilers, chemical reactors, and process lines. The sight glass typically features tempered borosilicate glass enclosed in a high-strength metal housing—usually stainless steel or an alloy resistant to corrosion.
In high-demand industrial environments where pressure and temperature exceed standard operating ranges, the High Pressure Sight Glass plays a vital role in ensuring process control, operational safety, and real-time monitoring. These specialized sight glasses provide a clear view into tanks, pipelines, and pressure vessels, supporting effective industrial flow monitoring and enabling operators to make informed decisions without interrupting production.
When choosing a sight glass for your system, several performance factors must be carefully evaluated:
Weld to tank
The Douglass ZW30 Weld-to-Tank Sight Glass is a high-performance solution designed for demanding industrial applications requiring enhanced durability and higher pressure ratings.
Suitable for tanks operating up to 300 PSI, the ZW30 is engineered to provide clear, reliable visibility into tank processes while withstanding the rigors of more intensive environments. Its robust construction allows for greater torque application, making it ideal for use with metal-inserted gaskets.
| Item | Part name | Material options |
|---|---|---|
| 1 | Cover Flange |
|
| 2 | Weld Pad |
|
| 3 | Sight Glass (max temp) |
|
| 4 | Gaskets *(max temp) |
|
| 5 | Bolts |
|
| ZW30-2 | ZW30-3 | ZW30-4 | ZW30-5 | ZW30-6 | ZW30-7 | ZW30-8 | |
|---|---|---|---|---|---|---|---|
| Visible Diameter (A) | 2" | 3" | 4" | 5" | 6" | 7" | 8" |
| Total Diameter (B) | 5" | 6" | 7" | 8-1/2" | 10" | 11" | 13" |
| ZW30-2 | ZW30-3 | ZW30-4 | ZW30-5 | ZW30-6 | ZW30-7 | ZW30-8 | |
|---|---|---|---|---|---|---|---|
| Cover (H1) | 3/4" | 3/4" | 3/4" | 1" | 1-1/4" | 1-1/4" | 1-1/2" |
| Weld Pad (H2) | 1" | 1" | 1" | 1-1/4" | 1-1/2" | 1-1/4" | 1-1/2" |
| ZW30-2 | ZW30-3 | ZW30-4 | ZW30-5 | ZW30-6 | ZW30-7 | ZW30-8 | |
|---|---|---|---|---|---|---|---|
| Ø | 3-3/4" | 4-3/4" | 5-3/4" | 7" | 8" | 9" | 11" |
| Thickness | 3/4" | 3/4" | 1" | 3/4" | 1-1/4" | 1-1/4" | 1-1/4" |
| ZW30-2 | ZW30-3 | ZW30-4 | ZW30-5 | ZW30-6 | ZW30-7 | ZW30-8 | |
|---|---|---|---|---|---|---|---|
| Bolt Circle Diameter (C) | 3-3/8" | 4-3/8" | 6-3/8" | 7-3/4" | 9" | 10" | 12" |
| Tightening Torque (ft/lbs) | 17 | 17 | 19 | 22 | 25 | 28 | 32 |
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