Model 121-A Flange Sight Glass
Circular sight glass fitting · ANSI 150 lb flange connection
About Model 121-A
A circular sight glass fitting, similar to DIN 28121, for observing and illuminating the inside of closed vessels such as boilers, tanks and silos.
Supplied fully assembled, ready to bolt onto an existing ANSI 150 lb flange.
- Working pressure
- 10 bar
- Working temperature
- 200°C
- ANSI sizes
- 1½, 2, 3, 4, 5, 6 and 8 inches
Construction and material options
- Base and cover flanges
- Steel or stainless steel 1.4571; other materials on request.
- Glass
- Borosilicate glass according to DIN 7080.
- Gasket
- PTFE enveloped gasket, up to 200°C.
Special designs and accessories
Designs above 200°C, higher pressures, 300 or 600 lb connections, safety double windows, sight glass light fittings and lined base flanges are available on request. Describe these under Application and special requirements.
Engineering dimensions
| ANSI size | bar | D | d₁ | d₅ | k | h | d₃ |
|---|---|---|---|---|---|---|---|
| 1½″ | 10 | 127.0 | 48 | 73.0 | 88.9 | 36 | 4 × Ø16 |
| 2″ | 10 | 152.4 | 65 | 92.1 | 120.6 | 38 | 4 × Ø19 |
| 3″ | 10 | 190.5 | 80 | 127.0 | 152.4 | 46 | 4 × Ø19 |
| 4″ | 10 | 228.6 | 100 | 157.2 | 190.5 | 46 | 8 × Ø19 |
| 5″ | 10 | 254.0 | 125 | 185.7 | 215.9 | 54 | 8 × Ø22.2 |
| 6″ | 10 | 279.4 | 125 | 215.9 | 241.3 | 54 | 8 × Ø22.2 |
| 8″ | 10 | 342.9 | 150 | 269.7 | 298.5 | 54 | 8 × Ø22.2 |
Certificates
Optional certificates according to EN 10204-2.2 or EN 10204-3.1.
Configure your Model 121-A
Select the size and material for your enquiry. Fields marked * are required.