Spirax Sarco BPM21L/BPM21LCV is a carbon steel pressure-balanced thermostatic steam trap with an integral stainless steel strainer, available with threaded or 1/2 in socket-weld connections and a maximum operating pressure of 21 bar g. The BPM21LCV is available with an integral check valve and is suitable for compact OEM steam equipment, small steam tracing lines, and condensate drainage from equipment branches connected to a common condensate return header.
BPM21L product photo
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Spirax Sarco BPM21L/BPM21LCV Carbon Steel Balanced Pressure Thermostatic Steam Trap
Compact carbon steel thermostatic steam trap for equipment drainage, with an optional built-in check valve
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Models
BPM21L and BPM21LCV are carbon steel pressure-balanced thermostatic steam traps with an integral stainless steel strainer. They support 3/8 in or 1/2 in BSP/NPT threaded connections, as well as 1/2 in socket weld connections only, with a PN25 design pressure rating. BPM21L is the standard version without an integral check valve and is suitable for normal applications with no significant risk of condensate backflow. BPM21LCV adds an integral check valve and is suitable for conditions where backflow may occur, including shutdown, vacuum operation, shared condensate return mains, or vertical outlet lift piping. Both models are supplied with an STD capsule as standard, discharging at 12°C below saturated steam temperature. Selection should be based on whether backflow prevention is required by the system.
BPM21LBPM21L Standard Pressure-Balanced Thermostatic Steam Trap
BPM21L is a carbon steel pressure-balanced thermostatic steam trap with a 1.0460(C22.8) carbon steel body and an integral stainless steel strainer. It supports 3/8 in and 1/2 in BSP or NPT threaded connections, as well as 1/2 in socket weld connections only. The body has a PN25 design pressure rating, a maximum allowable pressure of 25 bar g@120°C, a maximum allowable temperature of 242°C@20 bar g, and a maximum operating pressure of 21 bar g@217°C. The standard configuration uses an STD capsule, discharging at 12°C below saturated steam temperature. This model does not include an integral check valve and is suitable for standard steam trapping applications with no significant risk of condensate backflow.
BPM21LCVBPM21LCV Pressure-Balanced Thermostatic Steam Trap with Integral Check Valve
BPM21LCV is a carbon steel pressure-balanced thermostatic steam trap based on BPM21L, with an added integral check valve. It features a 1.0460(C22.8) carbon steel body and an integral stainless steel strainer. It supports 3/8 in and 1/2 in BSP or NPT threaded connections, as well as 1/2 in socket weld connections only. The body has a PN25 design pressure rating, a maximum allowable pressure of 25 bar g@120°C, a maximum allowable temperature of 242°C@20 bar g, and a maximum operating pressure of 21 bar g@217°C. The standard configuration uses an STD capsule, discharging at 12°C below saturated steam temperature. The integral check valve is suitable for applications where condensate backflow may occur, including shutdown, vacuum operation, shared condensate return mains, or vertical outlet lift piping.
Specifications
- Steam Trap Type
- Balanced pressure thermostatic steam trap
- Body Material
- Carbon steel 1.0460 (C22.8)
- Integral Strainer
- Integral stainless steel strainer screen
- Check Valve Configuration
- Optional integral check valve
- Connection Type
- Threaded or socket weld connections
- Thread Size
- 3/8 in, 1/2 in, BSP / NPT available
- Socket Weld Size
- 1/2 in only
- Body Design Pressure Rating
- PN25
- Maximum Allowable Pressure
- 25 bar g@120°C
- Maximum Allowable Temperature
- 242°C@20 bar g
- Maximum Operating Pressure
- 21 bar g@217°C
- Minimum Operating Temperature
- 0°C
- Design Cold Hydraulic Test Pressure
- 38 bar g
- Capsule Subcooling Discharge Temperature
- STD: 12°C below saturated steam temperature; NTS: 6°C below; SUB: 24°C below
- Installation Orientation
- Horizontal installation (cover facing upward) or vertical installation
- Pressure Equipment Compliance
- 97/23/EC
Application scenarios
Condensate Drainage for Compact OEM Steam Equipment
Suitable for individual OEM steam equipment installed where space is limited, for discharging condensate and air from the condensate outlet of a steam heat exchanger or steam chamber. The compact design and integral stainless steel strainer of the BPM21L are suitable for installation inside equipment.
Condensate Drainage for Independent Small Steam Tracing Lines
Suitable for independent small steam tracing lines, for discharging condensate and air generated during operation at the end of the line or at the condensate drainage point. The standard BPM21L is suitable for independent tracing lines without an elevation lift on the condensate recovery side.
Backflow Prevention and Condensate Drainage for Equipment Branches Connected to a Shared Condensate Recovery Header
Suitable for branches serving multiple small steam units connected to a shared condensate recovery header. The BPM21LCV with an integral check valve can discharge condensate from the equipment while inhibiting backflow when the equipment is shut down or the recovery-side pressure changes.
Selection points
Three capsule subcooling discharge temperatures available
STD, NTS, and SUB capsules are available, discharging condensate at 12°C, 6°C, and 24°C below saturated steam temperature, respectively.
BPM21LCV with integral check valve for backflow prevention
The BPM21L fitted with an integral check valve is designated BPM21LCV. It prevents condensate backflow during shutdown or under vacuum conditions, making it suitable for shared condensate return mains or installations with a vertical lift pipe at the outlet.
Integral stainless steel strainer
Both BPM21L and BPM21LCV are fitted with an integral stainless steel strainer.
Supports horizontal or vertical installation
The product can be installed horizontally with the cover facing upward, or vertically.
Carbon steel body material
The valve body is made of 1.0460(C22.8) carbon steel.
Installation & maintenance notes
Installation Orientation and Cover Direction
This steam trap may be installed horizontally or vertically. For horizontal installation, the cover must face upward.
Operating Limit Verification
Before installation, verify that site operating conditions meet the specified product limits: maximum operating pressure 21 bar g@217°C, maximum allowable pressure 25 bar g@120°C, and minimum operating temperature 0°C.
Model Selection for Backflow Prevention
Where condensate backflow must be prevented, select the BPM21LCV model with an integrated check valve. This model is suitable for applications with multiple units sharing a common recovery header or with a vertical lift pipe installed downstream of the steam trap.
Socket Weld Connection Specification Verification
Socket weld connections are available only for the 1/2 in size. Before installation, confirm that the selected connection type and size are compatible.
FAQ
What steam system applications is BPM21L suitable for?
BPM21L is a compact carbon steel balanced pressure thermostatic steam trap with an integral strainer. It is suitable for applications with limited installation space, such as individual OEM machinery, hospital sterilization equipment, and independently drained steam tracing lines without lift requirements.
What is the difference between BPM21L and BPM21LCV?
BPM21L features an integral stainless steel strainer screen without a check valve. BPM21LCV additionally incorporates an integral check valve, reducing the risk of condensate backflow during equipment shutdown or vacuum conditions. It is suitable for applications where multiple units share a common recovery header or where a vertical riser is installed downstream of the valve.
Which capsules are available for BPM21L, and how do their discharge temperatures differ?
The STD standard capsule discharges condensate at 12°C below saturated steam temperature; the NTS capsule at 6°C below; and the SUB capsule at 24°C below. The specific configuration should be confirmed according to the actual model and application conditions.
What connection types and sizes are available for BPM21L?
Threaded connections are available in 3/8 in and 1/2 in sizes, with BSP or NPT options. Socket weld connections are available only in 1/2 in size.
What should be considered when installing BPM21L?
The steam trap should preferably be installed horizontally with the cover facing upward, but vertical installation is also possible. A drip leg upstream of the valve is recommended, together with suitable isolation valves before and after the steam trap to facilitate maintenance and replacement. The capsule does not need to be removed when welding the connection to the pipe.
Documents
BPM21L Carbon Steel Balanced Pressure Thermostatic Steam TrapDatasheet · ChineseBPM21L Carbon Steel Balanced Pressure Thermostatic Steam TrapDatasheet · EnglishBPM21L Carbon Steel Balanced Pressure Thermostatic Steam Trap Installation and Maintenance InstructionsManual · EnglishBPM21L Carbon Steel Balanced Pressure Thermostatic Steam Trap Installation and Maintenance InstructionsManual · English