Spirax Sarco SP7 Smart Valve Positioner with HART 4-20mA for Energy Efficient Control Valves and NAMUR Mounting

Product Overview

The Spirax Sarco SP7 is a smart, electronically configurable electro-pneumatic valve positioner designed for mounting on pneumatic linear or rotary actuators that conform to NAMUR. It guarantees exact proportionality between the valve stroke and the electrical input signal (mA) into the positioner.

The SP7-1* has a cast aluminium housing that is treated for outdoor installation. The unit can be mounted onto pneumatic actuators with rotary travel of -57 to +57° or linear travel of -28 to +28°. The positioner can be supplied with or without a mounting kit and with or without a pressure gauge block. It operates with a control signal in mA and an air supply pressure from 1.4 to 6 bar. The positioner can also be used to reverse the action of the control signal.

The SP7-10 includes a local communication interface (LCI) as standard, with an optional HART communication module for communication via the 20mA signal. HART 5 or HART 7 are available. The SP7-11 offers a PROFIBUS PA module, and the SP7-12 offers a FOUNDATION Fieldbus module. A digital input can activate control system functions, and a digital output outputs collective messages (alarms/faults). The SP7 is one of the most energy-efficient positioners available, with a maximum steady-state air consumption of 0.015 SCFM, up to 50x more efficient than similar electro-pneumatic positioners.

Technical Specifications

Application Industry

The Spirax Sarco SP7 is used in steam control systems, process heating and cooling, food and beverage utilities, pharmaceutical clean steam, and general industrial valve control. It is suitable for applications where reliable digital positioning and energy efficiency are essential. The positioner can be used with any actuator that conforms to NAMUR, including Spirax Sarco BVA300, PN1600, PNS3000, PNS4000, PN9000, and TN2000 series actuators.

Common Problems

• Positioner does not respond to input signal: Check supply air pressure is within 1.4~6 bar. Verify pneumatic connections are secure. Check the air supply quality meets ISO 8573-1:2010 Class 3:3:3.

• Valve position does not match input signal: Check the characteristic curve setting. Verify that the operating direction is correctly set. Recalibrate the zero point.

• Slow valve response: Check supply air pressure and filter. Verify the air supply tube is not restricted.

• ERROR 10 (Power supply interrupted): The power supply was interrupted for at least 20 ms. The actuator is moved to the safe position. After approx. 5 seconds, the positioner is automatically reset.

• ERROR 11 (RAM error): The actuator is moved to the safe position. After approx. 5 seconds, the positioner is automatically reset and the RAM is reinitialized.

• SENS_ERR (Position sensor defective): The position sensor is defective. Contact service for replacement.

• ALARM 1 (Leakage between positioner and actuator): Check pneumatic tubing and fittings for leaks.

• ALARM 2 (Setpoint current out of range): Check the input signal source and wiring.

Replacement Models

The Spirax Sarco SP7 is a current-generation smart positioner platform. The SP8 Smart Positioner is the next-tier option from the same product line, offering advanced valve diagnostics with long-term data trending to benchmark current valve performance against a new control valve. For legacy installations, the SP7 serves as an upgrade from older Spirax Sarco EP5/EP6 series positioners and pneumatic-only positioners. For cross-vendor alternatives, verify actuator mounting, travel range, and communication protocol before ordering.