Product Overview

The Spirax Sarco MST21 is a precision-engineered thermostatic steam trap designed for reliable condensate discharge and steam containment in industrial process systems. Utilizing a balanced pressure thermostatic capsule, the MST21 responds to temperature differentials to discharge condensate, air, and non-condensable gases while preventing live steam loss. With a 1/2″ BSP threaded connection, this trap is a direct-fit replacement for OEM installations and is suitable for a wide range of low to medium pressure steam applications. Its compact, robust construction ensures long service life and minimal maintenance in demanding process environments.

Technical Specifications

ParameterSpecification / Feature
Component TypeThermostatic Steam Trap (Process & Pneumatic Valve)
Model DesignationSpirax Sarco MST21
Connection Size & Type1/2″ BSP (British Standard Pipe) Threaded
Operating PressureStandard Industrial Grade (Up to rated bar)
Operating TemperatureThermostatic capsule rated for saturated steam service
Mounting & ConnectionStandard ISO / Manufacturer Interface
Body MaterialCorrosion-resistant industrial grade construction

Engineering Features & Advantages

  • Precision Performance: Balanced pressure thermostatic capsule ensures accurate temperature response for efficient condensate discharge and minimal steam loss.
  • Industrial Reliability: Built for continuous operation under severe industrial conditions, with a robust body and internal components resistant to wear and corrosion.
  • Direct Fit Replacement: Exact dimensional and functional compatibility with original OEM standards, including 1/2″ BSP connection for straightforward installation.
  • Air and Gas Handling: Automatically discharges air and non-condensable gases during start-up and normal operation, improving heat transfer efficiency.
  • Compact Design: Space-saving footprint suitable for tight piping configurations without compromising performance.

Typical Industrial Applications

Ideally suited for steam distribution and condensate management in process industries, including:

  • Steam tracing and jacketed vessels in chemical and pharmaceutical plants
  • Unit heaters, heat exchangers, and coils in HVAC and process heating systems
  • Laundry, food processing, and sterilizing equipment requiring precise steam control
  • General steam mains and drip legs in industrial steam systems

PRODUCT IMAGES

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SPIRAX SARCO MST21 1/2″ BSP Thermostatic Steam Trap

âš¡ Emergency Plant Maintenance & Ready-to-Ship Notice:

  • Authentic & Fully Tested: 100% bench tested for hydraulic response, pressure rating, and null-bias stability before dispatch.
  • Fast Dispatch: In-stock units ready for same-day dispatch via DHL / FedEx Express directly to your plant.
  • Pre-Shipment Verification: High-definition photos, video testing runs, and serial number verification provided prior to shipment.
  • Peace of Mind: Covered by our 12-Month Replacement Warranty.

Shop the genuine SPIRAX SARCO MST21 1/2″ BSP Thermostatic Steam Trap. This UK-made 1/2″ BSP hydraulic component features a balanced pressure thermostatic capsule, delivering leak-free, reliable fluid control for heavy-duty industrial systems.

Tested Genuine Surplus / OEM Hydraulic Component
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Tested Genuine Surplus / OEM Hydraulic Component
WhatsApp RFQ Fast Quote