Spirax Sarco SP400 and SP500 valve positioners

The Spirax Sarco SP400 and SP500 valve positioners are claimed to be the most energy-efficient digital electro-pneumatic valve positioners available, based on steady state air consumption.

All pneumatic positioners leak some air holding an actuator in steady and transient state, and these leak rates are stated in positioner technical documentation. The SP400 and SP500 have recently been certified by Lloyds Registry EMEA to have a minimum leak rate of 0.48 dm³/hour, which greatly reduces the cost of wasted compressed air.

The SP400 and SP500 are quick and easy to install and commission, with the latter being complete in three button pushes or less. This simplicity of use minimises plant downtime, while non-contact position feedback technology reduces installation time and provides increased accuracy and reliability over mechanical linkages. The SP500 also supports the HART protocol.