Compare the positioner range
Return to positioners, controllers and sensors when you need to compare SP400 with SP500, SP7, EP500, EP6 and other feedback products.
Where SP400 sits in the control range
SP400 belongs in the Spirax Sarco positioners, controllers and sensors range. It is intended for pneumatic control valve duties that need position feedback, straightforward setup and low steady-state air consumption without a more complex communication package.
Compared with SP500, SP400 is the simpler option for standard positioning duties where 4-20 mA input, digital setup and reliable feedback are the main requirements.
Product characteristics
SP400 uses the input current signal to set the valve position, then compares that demand with valve position feedback and adjusts the actuator air output. This closed-loop correction helps overcome stem friction and process forces so the valve can hold the requested opening more consistently.
The non-contact feedback arrangement reduces mechanical linkage between valve and positioner, while piezo valve technology helps reduce steady-state instrument air use. Setup is supported by push buttons, an LCD menu and automatic commissioning routines.
Typical selection checks include actuator style, mounting standard, valve action, requirement for a pressure gauge block, air preparation quality and whether the positioner is being ordered alone or as part of a complete control valve package.
Related routes
- Return to positioners, controllers and sensors to compare SP400 with adjacent feedback and control products.
- Review pneumatic actuators when the immediate decision is the actuator platform.
- Review control valves when the valve body, actuator and positioner need to be selected together.