Corrosion protection enhancement for electric actuators

Paul Boughton
Michael Herbstritt outlines a new coating process to protect actuators against chemicals, weather and mechanical impact.

Over the past decade, the quality demands for corrosion protection from offshore applications have considerably increased and this has required corresponding enhancements to products supplied to the industry.

Exploration engineering is a developing sector and soaring energy costs have led to a growth in oil and gas extraction. And, regardless of location - whether in the tropics or polar latitudes - this work is conducted in increasingly extreme, open sea environmental conditions. As a result, Auma has developed a new two-layer powder coating process at its Muellheim manufacturing campus in Germany, which has advanced device capability.

Recognising that corrosion protection is a basic requirement for electric actuators, AUMA has made major investment in upgrading its procedures for coating components. The new procedure has required design modification of the company's components and this has had a major impact on AUMA's manufacturing process.[Page Break]

Single housing parts are now coated prior to assembly: as a result, whenever housing is opened for installation, commissioning or other procedures, there is no increased risk of corrosion.

The new process incorporates a first layer for optimum adhesion of the finish coating and a second layer which ensures resistance to chemicals/the weather and mechanical impact.

The initiative from AUMA protects individual elements of the housing and represents a paradigm shift for the global actuator supplier. Previously, a finish coating was applied after final device assembly.

Commenting on the advancement in actuation, AUMA joint Managing Director Henrik Newerla said: "This is a significant breakthrough that marks a revolutionary production change for AUMA and offers major advantages to users in challenging oil and gas installations which often face the rigours of environmental factors such as the sea and extreme weather conditions.

"Corrosion protection is an integral part of the adaption of housing design and device enhancement. Keeping risk of corrosion damage to a minimum is therefore a central focus for our designers.[Page Break]

"Heavy financial commitment to research ensures that new materials and procedures are continuously tested to verify their corrosion protection characteristics, and to assess their appropriateness for use with our devices. Significant outlay is made at AUMA to continuously review materials and methodologies to provide the optimum solution."

Rigorous assessment has played a key role in the advancement to electric actuation and new processes and test equipment include salt spray chambers which subject the elements of the company's actuators to extreme corrosive conditions for extensive periods. AUMA reports that the duration of the test exceeded all specifications and after 2,500 hours the assessment was interrupted as no significant corrosion damage could be detected.

Having differentiated its range with a modular design principle, AUMA reports that enhanced corrosion protection has raised the bar for the actuation industry and is an additional USP for its products.

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Michael Herbstritt is an electronic engineer and technical author with AUMA, Muellheim, Germany. www.auma.com

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