Tubular Level Gauges are designed to view liquid levels using clear or red line Borosilicate (Pyrex) tubing to view liquid levels. All valves use a stuffing box configuration to seal the glass tube, and have a ball check shutoff to prevent loss of vessel contents in case of glass failure. Operating pressure and temperatures are subject to the limitations of the tubular gauge glass and washer composition.
| Materials |
| Valves: |
316 SS; Ductile Iron; Bronze; etc. |
| Seals: |
Rubber; Neoprene; Viton® etc. |
| Glass: |
Clear or Red Line Borosilicate (Pyrex) Tubing |
| Guard Rods: |
Stainless Steel or Bronze |
| Connections: |
1/2" or 3/4" Male NPT |
These valve bodies are rated for 500 PSIG at 450F. The actual pressure limitations are of the gage glass. These sets are usable with oils and petrochemical liquids. Use with water or steam is not recommended due to the possibility of the steel valves developing rust or corrosion.
The following pressure values are for industry standard high pressure gage glass use. The steam services values are for reference only. For actual steam service, choose stainless steel valves.
| Gage Glass Length (Inch) | Temperature Up To 150F Without Corrosion (PSIG) | Steam Boiler Service up to 425F (PSIG) |
| 8 | 425 | 315 |
| 10 | 410 | 310 |
| 12 | 400 | 300 |
| 14 | 385 | 290 |
| 16 | 370 | 280 |
| 18 | 355 | 275 |
| 20 | 345 | 265 |
| 24 | 315 | 250 |
| 30 | 275 | Not Recommended |
| 36 | 240 | Not Recommended |
| 48 | 190 | Not Recommended |
This sight glass has been certified as maintaining a Quality Assurance System in accordance with the Pressure Equipment Directive 97/23/EC (PED) Annex I, Paragraph 4.3 by the Certification Body 0036 of the TÜV Industrie Service GmbH.
