Valve Magazine - Summer 2008

ties are included. Valving controls pressure to the actuator with no continuous air bleed (Figures 9 and 10).

Accessory-External-Modulating-Remote (AEMR): While mounted to the actuator in a manner similar to AEDRs, AEMRs employ digital “smart” positioner technology to sense actuator motion and to provide the appropriate supply pressure to cause the desired PST actuator travel. AEMRs provide continual feedback regarding valve and actuator motion along with diagnostic data, and they accept either remote or local PST activation. Suppliers point out that AEMRs (as with some MEMLs, MIARs and AEDRs) are able to perform the PST automatically with no operator intervention. Signature testing is a normal feature allowing the identification of failing valves before they become unavailable as well as automatic documentation of emergency events. AEMRs remain able to

User’s Choice In selecting the Figure 11 – A position- ^proper ^PSTD ^tobased AEMR mounted employ, users directly to the ESD valve must determine ^actuatorthe answer to a number of questions: Is the relative simplicity of a manually engaged PSTD desired, or is an accessory-based PSTD more applicable with its expanded diagnostics capabilities? Is a hard stop preferred, or will sensor-controlled travel limits do the job—or should there be a combination of both sensor and hard stop? Is emergency response during PST important and is redundancy of components or a relative minimal number of components a better choice? How frequently will the PST be activated? Which supplier can provide

respond to an emergency event during the PST (Figure 11).

ACKNOWLEGEMENT:

The author appreciates the assistance of the following companies, which provided information for this article:

ASCO ( www.ascovalve.com)

Dyna Torque ( www.dynatorque.com)

Emerson Process Management-Fisher Controls (www.emersonprocess. com/fisher)

Morin ( www.morinact.com)

QTRCO ( www.qtrco.com)

Topworx ( www.topworx.com)

superior support in your quest to satisfactorily achieve a mandated safety integrity level?

The user is left to determine what is important for each application, knowing that each type of PSTD will add significantly to plant safety while helping to keep process and revenue flowing. VM

ED HOLTGRAVER is CEO of QTRCO, Inc., located in Tomball, TX. He is a member of the Valve Manufacturers Association Education & Training Committee and the Valve Magazine Editorial Board. Reach him at edholtgraver@qtrco.com.

Jet-speed setup

The EIM TEC2000 valve actuators at the Atlanta international airport’s jet-fueling facility were commissioned in an average of just 3 minutes each.

The secret to this speed is the actuator’s large IconoText LCD screen. It enables users to quickly perform non-intrusive setup through a menu of simple, plain-language prompts—with no tools.

Specify TEC2000 for your next facility. Because simple setup means faster setup.

The biggest, brightest display screen in the industry, plus simple, plain-language setup menus allow operators to read the actuator… instead of a manual.

EIM CONTROLS
13840 Pike Road, Missouri City, TX 77489
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The EIM TEC2000 valve actuators in this jet-fueling facility at Atlanta’s international airport were commissioned in an average of just three minutes each.