Saturday, July 22, 2006

Piezo valve operator is fieldbus compatible

ASCO Joucomatic's new IS Piezo valve operator combines the benefits of low power energy saving with intrinsically safe operation and the ability to operate in fully distributed fieldbus systems.
ASCO Joucomatic's new IS Piezo valve operator combines the benefits of low power energy saving with intrinsically safe operation and the ability to operate in fully distributed fieldbus systems: Profibus PA or Fieldbus Foundation. The unique ceramic multilayer technology of the piezo operator means that just 8.4 milliwatts is required to operate 3 way and 4 way valves with port sizes up to 1in and CVs of up to 13. The IS Piezo operator is the first of its type suitable for fieldbus controlled industrial processes.

Operating on a 2-wire transmission medium, which obviates the need for local hardwiring, up to 125 IS Piezo operators can be configured, each controlling a process valve, over a Profibus PA fieldbus network which is expandable up to 10km.

In addition to their fieldbus compatibility, the IS Piezo valves are also designed for use in intrinsically safe systems, with ASCO 3 way and 4 way valves, in water treatment, petrochemical and process control applications.

The IS Piezo valves have USA FM (Factory Mutual) approval for use in IS systems, with SA, CE and Cenelec EEXia IIC, T6 pending.

The design of the IS Piezo valves incorporates a (patent pending) multi-layer ceramic arm operator that produces a change in state to open and close an orifice when supplied with minimal electric current (minimum 1.4mA).

The fact that there are no moving parts in this operation offers several benefits: firstly, response times are exceptionally fast: secondly, service life is practically unlimited: thirdly, since the valves are operated by voltage alone, power consumption is minimal at just 0.008mw.

The unique operation of the Piezo valves means that there are no inductive peaks when switching, so unlike conventional solenoid valves, no circuit protection is necessary.

No holding current is required for the valves to maintain position, so heat generation is not a problem either.

The IS Piezo valves are available in three versions; each rated by their current consumption at the common operating voltage of 6-30volts DC.

Ultra Low Current units are rated 1.4 - 2.3mA, Intermediate at 1.7 - 3.72mA and Low Current variants at 5.15 - 9.32mA.

All versions of the valves operate in the pressure and temperature range from 2 - 6bar and -10degC to 60degC, and all offer high levels of environmental protection.

The valves are enclosed in corrosion resistant thermoplastic housings, which are potted with epoxy to provide Nema Type 4 and 4X protection ratings.

In addition, the valves benefit from 50 micron filtration on their inlet ports and are equipped with sealed exhausts to prevent contamination entering the piezo operator.