ERIKS pump repairs make £4k annual saving at UK auto plant

The story began when ERIKS evaluated the efficiency of one of the automotive company's pumps. The pump in question was a 22kW ELPO, which handles process water for a metalwork pre-treatment process prior to body coating. The result of the test was that the pump was found to be under-performing by at least 30 per cent against the manufacturer's original test data.

This unit was then dismantled and all components examined for wear. The examination revealed that the pump was heavily corroded and the impeller worn, burred and imbalanced. In addition, the mechanical seal had seized and the pump was out of alignment with the motor. And there were further problems: the volute was cut-water worn, the bearings showed evidence of fretting and corrosion and the motor was not inverter rated. To improve pump efficiency, a repair programme was conducted by ERIKS and Henkel, who have formed a partnership to assure best practice in pump repair. The partnership combines ERIKS proven engineering expertise with Henkel's experience and know-how in ceramic and energy-saving coatings. Using this shared experience, ERIKS and Henkel provide repairs that are undertaken to the highest standards of workmanship using the best products for the job.

The repair work was conducted at ERIKS' EMS Workshop in Southampton. Some of the components required coating with Henkel's Loctite polymer composites, so the first step was to steam-clean these parts to remove any residue and salts. Castings, impellers and volutes are all subject to wear due to corrosion, erosion, cavitation and mechanical damage and all can be effectively and economically repaired with Henkel's Loctite surface engineering products. Parts were then blasted to achieve a surface roughness of 75 microns.

With this preparation work completed, the treatment of surfaces began. The substrates were pre-treated with Loctite 7515 to prevent corrosion and improve adhesion between the metal parts and the polymer composites. Loctite 7117 was applied as a "hold coat' to smooth surface imperfections and provide a better key for the thicker layers required to return the pump to its original dimensions. Loctite 7226 was used as the "build coat' to replace many years of wear and provide a tough surface, resistant to future wear. A further layer of Loctite 7117 was applied over Loctite 7226 to create a smooth finish, which will reduce friction within the pump and improve its energy efficiency.

New bearings and seals

To complete the repair work, the pump was fitted with new bearings and both oil and mechanical seals. The impeller was dynamically balanced, the pump re-assembled and a new 22kW high efficiency motor fitted. Motor and pump were then fitted to the bedplate and laser aligned.

With the repair work completed, a second performance test was carried out to measure the improvements that had been achieved. The results were outstanding; the remedial work had restored the pump to original specification, increasing its efficiency by 30 per cent.

An estimated energy reduction of 3936 was calculated for the first year alone (calculated at 0.08/kWh at 12 hours per day with an 80 per cent load). It was therefore clear that the cost of the repair, which amounted to 5542, would soon be recovered and that substantial savings were to follow. Over a five-year period, this accrues to a five-year energy saving amounting to 19,680. On carbon emission, the annual saving is 28 tonnes.

The repair work carried out by ERIKS and Henkel provided a tough protective coating to protect parts against attack. By applying Loctite polymer composites coatings and compounds, the treated surfaces benefit from excellent wear resistance against abrasion, erosion, corrosion and chemical attack, plus superior adhesion. By restoring the worn surfaces, the repair work conducted by ERIKS and Henkel has extended part life, increased component efficiency, cut replacement costs and reduced spare part inventory.

On one pump alone, the manufacturer has made significant savings in costs and emissions and is now evaluating the potential energy savings that could result from further repair programmes conducted by Henkel and ERIKS.

For further information about pump repairs, please email [email protected], or go to www.eriks.co.uk.