Description
Spirax Sarco single-window and double-window sight glasses feature threaded connections and are available with bronze or brass bodies depending on nominal size. They are suitable for steam systems and other industrial liquid systems. Installed downstream of steam traps, they allow operators to verify whether traps are functioning correctly. When multiple steam traps discharge into a closed condensate recovery system, sight glasses make it easier to check the operation of each trap. They can also indicate other steam system conditions, such as the presence of free oxygen and carbon dioxide in steam through solid deposits on the sight glass, or organic deposits in boiler feedwater. The double-window design provides a clear-through view and is standard for larger sizes; backlighting can be used to improve observation of flow conditions.
Standards
This product complies with the European Pressure Equipment Directive 97/23/EC.
Certificates
An EN 10204 2.2 certificate is available for this product. Note: Specify the certificate requirement when ordering.
Sizes and Pipe Connections
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Single window: 3/8”, ½”, ¾” and 1” threaded BSP or NPT.
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Double window: ½”, ¾”, 1”, 1¼”, 1½” and 2” threaded BSP or NPT.
Materials
| No. | Component | Material |
|---|---|---|
| 1 | Body | ½” - 1”: brass, EN 12165 CW617N; 1¼” - 2”: bronze, BS EN CC491K |
| 2 | Window frame | Brass, EN 12165 CW617N |
| 3 | Window | Toughened soda-lime glass, BS 3463 |
| 4 | Top gasket | Reinforced exfoliated graphite |
| 5 | Bottom gasket | Reinforced exfoliated graphite |
Pressure/Temperature Limits
| Body design condition | PN5 |
|---|---|
| PMA maximum allowable pressure | 5 bar g@ 90°C |
| TMA maximum allowable temperature | 148°C@3.5 bar g |
| Minimum allowable temperature | -29°C |
| PMO maximum operating pressure for saturated steam | 3.5 bar g |
| TMO maximum operating temperature | 148°C |
| Minimum operating temperature | 0°C |
| Note: Consult Spirax Sarco below this temperature | |
| Maximum cold hydraulic test pressure | 7 bar g |
| PTMX maximum test pressure (steam) | 3.5 bar g |
Weight (Approximate)
Single window
| Size | Weight |
|---|---|
| 3/8” | 0.6 kg |
| ½” | 0.6 kg |
| ¾” | 0.7 kg |
| 1” | 0.9 kg |
Double window
| Size | Weight |
|---|---|
| ½” | 0.9 kg |
| ¾” | 0.9 kg |
| 1” | 1.2 kg |
| 1¼” | 1.9 kg |
| 1½” | 1.8 kg |
| 2” | 2.5 kg |
Safety Information, Installation and Maintenance
For detailed information, refer to the Installation and Maintenance Instructions supplied with the product (IM-S32-04).
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Warning: In some applications, condensate can have a dissolving effect on sight glass materials, particularly when the water contains corrosive alkaline or acidic substances. Regularly inspect the sight glass. If thinning is detected, replace the glass immediately. Wear safety glasses to protect your eyes when viewing the sight glass.
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Installation and maintenance: Install isolation valves upstream and downstream of the sight glass. Close the upstream isolation valve first to prevent pressure overload. When installing downstream of a discharging steam trap, such as a thermodynamic steam trap, maintain a minimum distance of 1 m. This helps protect the sight glass from thermal and pressure shock. Take appropriate measures to ensure that broken glass cannot injure personnel or damage equipment if the sight glass fails. Provide adequate access for maintenance.
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Disposal: This product is recyclable and, when disposed of properly, does not present an environmental hazard.
Ordering
Example: 1 - Spirax Sarco 1” double-window sight glass, BSP threaded connection, brass body and removable toughened soda-lime glass.