Background
A Hangzhou-based enterprise uses imported Spirax Sarco steam control valves for its coating machine temperature control system. Due to long-term operation, severe stem leakage has occurred, and the overseas supplier is unable to provide after-sales support, making the hidden safety hazard unsolvable and restricting production. To ensure stable operation and reduce costs, the enterprise selected the GRAT pneumatic single-seat control valve as a replacement, addressing the lack of after-sales service and valve stem leakage issues while meeting the precise temperature control requirements of the coating machine.
Key challenge
- Difficult Installation Adaptation: Limited on-site space and the positioner close to the wall made conventional installation inconvenient.
- Positioner Malfunction: The customer reversed the cylinder and accessories on their own without recalibrating the positioner, resulting in air leakage.
- Poor Temperature Control Accuracy: Inconsistent brands of old and new positioners and mismatched system parameters caused large temperature fluctuations, preventing normal equipment operation.

Operation Condition
Product Name: Pneumatic Single-Seat Control Valve
Application: Temperature regulation for coating machines
Medium: Steam
Nominal Diameter: DN25
Pressure Rating: 1.6 MPa
Actuation Mode: Single-acting
Medium Temperature: 250 ℃
Sealing Type: Hard seal
Connection Type: Flanged
Power Supply: AC220V
Commissioning Date: December 2025
Location: Hangzhou
Performance Result
- Fault Resolution: Remote guidance for resetting, calibrating the positioner and reconfiguring parameters eliminated air leakage and temperature fluctuations.
- Stable Operation: Hard seal design is suitable for high-temperature steam, completely eliminating valve stem leakage and enabling precise temperature control to guarantee production.
- Cost Optimization: Domestic valve matched with imported positioner resolved the after-sales shortcomings of imported products and significantly reduced procurement and maintenance costs.
- Standard Improvement: Clarified the requirement for positioner recalibration after installation, providing experience for subsequent operation, maintenance and replacement projects.


