Acid Solution
3 Dec 2014
To move acid at a nuclear plant, pumps with zero leakage were needed.
Pumping corrosive liquids presents many problems, not least in respect to the material type and sealing arrangement required.
The Pump Company, based in Crawley, was approached by one of the UK’s leading firms of consulting engineers about a nuclear project it was working on that required the pumping of hydrofluoric acid.
The Pump Company had no hesitation in selecting pumps from Affetti Pumps in Italy, which specialises in the design and manufacture thermoplastic pumps.
Hydrofluoric acid is a highly corrosive liquid and is a contact poison.
It has to be handled with extreme care and it is capable of dissolving most metals and glass, so the correct material selection is of paramount importance.
For the application the end user required two pump arrangements, one with close coupled conventional end suction pumps, and the other with close coupled self-priming capability.
The project required full Quality Assurance documentation in line with ISO 9001 including data sheets, witnessed performance testing and material certificates with full traceability.
The pumps selected for the duty were manufactured from solid PVDF and magnetic drives were specified to ensure zero product leakage.
With required flows ranging between 2-20m3/hr and heads from 10 to 40m, all the self-priming pumps were subjected to witnessed testing on a maximum suction lift of 3.5m.
The specification demanded that all flanges had to be ANSI 150lbs RF.
Due to the highly corrosive nature of hydrofluoric acid a special filling and drainage arrangement was designed along with a purposebuilt bedplate.
All the pumps were arranged in a close coupled configuration employing 1.1 - 5.5kw motors. In total, The Pump Company supplied 18 pump sets. Affetti Pumps manufactures a full range of thermoplastic and fibreglass pumps that are available in both horizontal and vertical arrangements and comply with the required ANSI or ISO standards.
The Affetti MMB centrifugal close coupled magnetic driven pump range has been designed to solve the different problems generated from the leakage through the mechanical seals, with the consequence to cause serious environmental contamination.
Suitable to transfer acid and basic solutions, the wet ends are produced in thermoplastics (PPV-PVDF) and O-ring manufactured from elastomer material (EPDM-FPM-FEP).
The MSP centrifugal close coupled self-priming pump range has been designed for installations where it is not possible to install a flooded pump. These pumps can prime from a negative suction head of 4m.
Prior to dispatch of the pumps, the end user’s maintenance team visited the Affetti factory in Italy for a full training programme on how to commission the pumps, dismantle and rebuild the units, and once again witness the pumps’ suction capabilities on the test bed.
