Spirax Marshall BPT21Y Balanced Pressure Thermostatic Steam Trap

The Spirax Marshall BPT21Y is a carbon steel balanced pressure thermostatic steam trap equipped with an integral Y-type strainer screen. Designed for efficient condensate drainage and air venting on steam mains, tracing lines, and process equipment, it automatically discharges cold condensate and non-condensable gases while preventing live steam loss.

Forged from ASTM A105 carbon steel, the BPT21Y is rated for pressures up to 21–32 bar and temperatures reaching 285°C–300°C.

Core Performance & Features

• Integral Y-Strainer Protection: Built-in Y-type strainer screen traps scale, rust, and pipe debris to protect internal seat surfaces.
• Rapid Start-up Air Venting: Automatically opens on start-up to purge cold air and non-condensable gases quickly.
• Tight Sealing: Closes tightly near saturated steam temperatures to eliminate live steam loss.
• Inline Capsule Serviceability: Internal thermostatic capsule can be replaced quickly in the field without removing the valve body from the pipeline.
• Forged Steel Durability: ASTM A105 body provides high thermal shock resistance and mechanical strength.

Technical Specifications

Primary Applications

• Steam Tracing Lines: Ideal for critical and non-critical steam tracing headers and jacketed pipe systems.
• Air Venting Services: Works exceptionally well as a standalone thermostatic air vent on steam mains and equipment headers.
• Steam Main Drips: Reliable condensate removal for low-to-medium capacity steam distribution lines.