When it comes to testing, usually only the final testing of the pumps comes to mind. Acknowledging that the final testing is an important part of the manufacturing process, we must also recognise that testing is a continuous process from the start to the end of the project and final delivery. Testing is a major part of the pump manufacturing chain. Successfully tested pumps will run reliably for a long time but non-tested pumps may only impose cost and delay to the customer and the manufacturer.
At Sterling Pumps, every product leaving the factory is tested before shipping and depending on the type of project, different tests are conducted.
At Sterling Pumps, every product leaving the factory is tested before shipping and depending on the type of project, different tests are conducted.
- Positive Material Identification (PMI): Where special materials are specified Sterling Pumps will supply the manufacturers Material Certificate. Each material arriving at Sterling Pumps will also be verified using an X-ray PMI machine and the result will be recorded and kept. We will address the importance of material verification by PMI testing in a separate article.
- Castings:Where required, cast components are subjected to chemical analysis at the foundry and a valid material certificate will be issued for that component. Types of tests vary based on the applying standards and project requirements. This may include chemical analysis, mechanical property testing, hardness testing, corrosion testing and metallographic examination. In cases where these tests are required, they will be performed by NATA approved laboratories.
- Dimensional Checks:Each pump component is subjected to a full dimensional check after machining or fabrication. A dimensional check is also performed on the finished product where the critical dimensions and interfaces between the work scopes of different parties needs to be checked. A full record of dimensions checks will be kept as an As-built drawing.
- Assembly and clearance check:Parts and components will be checked again at the time of assembly. Check points during assembly are correct and easy fitting, free rotation, correct clearances and final assembled dimensions.
- Hydrostatic tests for pressure containing components: Where required, pressure containing components are subjected to hydrostatic test. This test can be performed either on an assembled pump or on individual components. As a minimum, test pressure is 1.5 times of Maximum Allowable Working Pressure.
- Final Testing:Sterling Pumps has one of the biggest pump testing capacities in Australia. Our test facility includes a 2m diameter x 15m deep pit plus 3 additional above ground tanks which give us the total capacity of 100,000 litres. It also includes a diesel power generator to test the motors up to 280 kW and bigger generators will be hired where required. All instruments are regularly calibrated by NATA approved laboratories.
Different tests may be applicable to the pumps based on the project requirements. Normally the following tests are performed on the pumps where applicable:
- Pump performance testing: every pump is subject to performance test. During this test, 5-6 points will be captured and the performance curve will be plotted. Then the actual performance curve will be compared against the design curve. Acceptance criteria are different per the different testing standards and rely on the project specification and customer requirement.Usually pumps are compared to one of the following standards where applicable: ISO 9906 Gr. 2, AS 2417 and API610. Standards for testing of fire pumps usually are AS2941, NFPA20 and FM.
- Mechanical running test: Where applicable pumps will run with the actual drive for a certain period to make sure all mechanical and electrical characteristics are as per pump design. Testing period varies from 15 minutes to 4 hours project to project. Vibration, temperature and noise values are recorded during this test.
- Logic and functional tests:Logic and functional tests are mostly applicable to fire water pumps. Control panel logic and functions will be checked during this test.
Successful testing is not just a relief for the pump manufacturer but also an assurance key to the end user for a reliable pump performance throughout the life time, subject to properly scheduled maintenance.
Hamid Shilani