Introduction
The BPM21L is a compact carbon steel balanced pressure thermostatic steam trap with an integral strainer. It is ideal for equipment with limited installation space, including OEM machinery.
Model Configuration and Options
| Model | Connection | Integral Strainer Type | Integral Check Valve | Standard Capsule | Typical Application and Selection Guidance |
|---|---|---|---|---|---|
| BPM21L | Threaded (3/8 in. and 1/2 in.) or socket weld (1/2 in. only) | Integral stainless steel strainer | No | STD standard capsule | Compact standard model: Suitable for standalone OEM equipment, hospital sterilizers, and independently drained steam-tracing lines with no lift requirement. |
| BPM21LCV | Threaded (3/8 in. and 1/2 in.) or socket weld (1/2 in. only) | Integral stainless steel strainer | Integral check valve | STD standard capsule | Compact anti-backflow model: The integral check valve prevents condensate from flowing back during equipment shutdown or vacuum conditions. Suitable for compact systems with a shared condensate return main or a vertical lift downstream of the trap. |
Capsule Options and Operation
Standard capsule (STD): discharges condensate at 12°C below saturated steam temperature.
NTS capsule: discharges condensate at 6°C below saturated steam temperature.
SUB capsule: discharges condensate at 24°C below saturated steam temperature.
Check valve: an integral check valve is available for all BPM21L sizes. With the check valve fitted, the model designation becomes BPM21LCV.
Standards
This product fully complies with the European Pressure Equipment Directive 97/23/EC.
Certification
A manufacturer’s test report is available for this product.
Note: Specify the requirement when ordering if certification is required.
Sizes and Pipe Connections
- Threaded connections: 3/8 in. and 1/2 in. BSP or NPT.
- Socket-weld connection: 1/2 in. only.
Operating Range (ISO 6552)
Do not use the product in this area. Do not use the product in this area, as internal components may be damaged.
Limiting Conditions
| Body design conditions | PN25 | |
| PMA | Maximum allowable pressure | 25 bar g @ 120°C |
| TMA | Maximum allowable temperature | 242°C @ 20 bar g |
| Minimum allowable temperature | -10°C | |
| PMO | Maximum operating pressure | 21 bar g @ 217°C |
| TMO | Maximum operating temperature | 242°C @ 20 bar g |
| Minimum operating temperature | 0°C | |
| Design maximum cold hydraulic test pressure | 38 bar g | |
Materials
| Item | Part | Material | Specification |
|---|---|---|---|
| 1 | Cover | Carbon steel | 1.0460 (C22.8) |
| 2 | Capsule | Stainless steel | |
| 3 | Seat | Stainless steel | |
| 4 | Strainer screen | Stainless steel | |
| 5 | Cover gasket | Nickel-reinforced graphite | |
| 6 | Body | Carbon steel | 1.0460 (C22.8) |
| 7 | Cover bolts | Carbon steel, M8 × 25 mm | BS 1506-621 A B7M |
| 8 | Seat gasket | Stainless steel | |
| 9 | Partition plate | Stainless steel | |
| 10 | Spring | Stainless steel |
Discharge Capacity
Dimensions and Weight (approximate), mm and kg
| Size | A | B | C | D | E | Weight |
|---|---|---|---|---|---|---|
| 3/8 in. | 70 | 62 | 35 | 15 | 20 | 0.9 |
| 1/2 in. | 70 | 62 | 35 | 15 | 20 | 0.9 |
Safety Information, Installation and Maintenance
For full details, see the BPM21L Carbon Steel Balanced Pressure Thermostatic Steam Trap Installation and Maintenance Instructions.
Installation Guidance
The trap is designed for horizontal installation with the cover uppermost, but it may also be installed vertically. A drop leg upstream of the trap is recommended. The capsule does not need to be removed when welding the trap into the pipeline. Fit suitable isolation valves upstream and downstream of the trap to simplify maintenance and replacement.
Ordering Information
Example: Spirax Sarco BPM21L balanced pressure thermostatic steam trap, 1/2 in. BSP threaded connection, carbon steel body with integral strainer, STD capsule, discharging condensate at 12°C below saturated steam temperature.
Spares
Available spares are shown in solid outline. Items shown in broken outline are not supplied as spares.
| Description | Item numbers |
|---|---|
| Capsule and seat assembly | 2, 3, 5, 8, 9, 10 |
| Gasket set | 5, 8 |
| Strainer screen (pack of 3) | 4 |
Ordering Spares
Order spares using the descriptions in the table above and specify the trap assembly: Spirax Sarco 1/2 in. balanced pressure thermostatic steam trap BPM21L, discharging condensate at 13°C below saturated steam temperature.
