Atex Triple Screw Pump for Lube Oil Recirculation
Power stations require all equipment to be robust and reliable as their operations are critical to the functions of businesses and households nationwide. Failure of apparatus for even short amounts of time can cause losses in revenue to cascade into hundreds of thousands of pounds. It is also very common that any machinery installed must comply to Atex standards as plant rooms are often non-safe areas, ensuring equipment is explosion proof safeguards the lives of the engineers working on site.
The Power Station's Process
A UK power station was modernising various processes across site, this involved the upgrade of one of the lube oil pumps. The existing gear pump was extremely old and required maintenance frequently and was causing significant amounts of down time and ultimately costs. It was a small pump handling low viscosity lubricating oil; however, it was critical to operations and replacing it had become a priority.
We worked closely with the project manager to obtain as much information about the existing equipment and the process as possible to ensure we fully understood their requirements and could select the most efficient design for them. The original low flow gear pump was fitted with an Atex motor as the plant room is a non-safe area, frequent maintenance of the internal gears and gearbox was causing a headache for the engineers and they wanted to avoid these issues with the replacement unit if possible.
Our Triple screw Oil Safe Pump Selection
After understanding the fluid details, flow rate and pressure requirements, we selected an Imo ACE 038K3 NVBP triple screw oil safe pump with a Siemens motor rated to EEx de IICT4 for safety.
Screw pumps are excellent at handling fuels, oils, and other clean lubricating liquids, they also have numerous benefits over other types of positive displacement pump such as gear pumps. For example, screw pumps produce low noise levels due to their modern design, they also produce low pulsations for a smooth and more constant flow.
One of the main benefits over other positive displacement pumps is that they are more compact as a gearbox is not required, meaning the motor is directly coupled operating at full speed, this leads to a higher pump efficiency as mechanical efficiencies are not lost through the gearbox. The absence of a gear box also makes maintenance a far simpler and cheaper process, a problem that was plaguing this customer, making it the ideal choice an electric oil transfer pump.
Screw pumps are self-priming and can therefore perform a suction lift and handle fluids containing trapped air, perfect for when the pump suction is installed above the fluid line. We installed the supplied unit with an integral relief valve to protect the pump and system from overpressure.
This is typically set to around 10% above the operating pressure, the valve is triggered if the pressure reaches the pre-set and the fluid is recirculated through the pump head to stop the pressure building in the line and damaging the pipework or any components such as valves and flowmeters.
Below is the specification of the pump that was installed:
Cast Iron casing, treated steel drive screw and treated cast iron idler screws
DN 40, PN16
1.1Kw, 1450RPM, 400V/690V/3Ph/50Hz, EEx de IICT4
Read our Screw Pumps vs Gear Pumps Guide Here: https://www.northridgepumps.com/article-73_screw-pumps-vs-gear-pumps-guide?catid=195