Winston Engineering Case Study

Case Study 7 WILDEN PUMP MUFFLER ICING Why does icing occurs on muffler during pump operation? Mufflers are included and recommended to be installed on AODD pumps because they can generate high decibel levels at full speed.  AODDP are driven by Compressed air.  When the compressed air enters the centre block, it  is channelled through the pump air valve and exhaust through the muffler. During this process, rapid temperature change occurs. Air temperature is well below freezing at the muffler exhaust and this causes icing-related issues.  This is more common in high humidity environments. How to prevent? Symptoms that shows pump is having icing related issues are as follows Pump is operating erratically Visible sign of ice formation on the muffler Possible cause for icing is - the inlet air has high levels of moisture  Remedy Try the below solutions to eliminate icing related issues and restore your pumps efficiency. ...

Case Study 6 What is a VFD? A Variable Frequency Drive (VFD) is a type of motor controller that drives an electric motor by varying the frequency and voltage supplied to the electric motor. Other names for a VFD are variable speed drive, adjustable speed drive, adjustable frequency drive, AC drive, microdrive, and inverter. How does a Variable Frequency Drive work? The first stage of a Variable Frequency AC Drive, or VFD, is the Converter.  The converter is comprised of six diodes, which are similar to check valves used in plumbing systems.  They allow current to flow in only one direction; the direction shown by the arrow in the diode symbol. For example, whenever A-phase voltage (voltage is similar to pressure in plumbing systems) is more positive than B or C phase voltages, then that diode will open and allow current to flow. When B-phase becomes more positive than A-phase, then the B-phase diode will open and the A-phase diode will close. The s...

Case Study 5 What is the difference between: SPL – Sound Pressure Level (in dBA ) SWL – Sound Power Level (in watt) SPL – Sound Pressure Level (in dBA ) A sound level meter is used for acoustic (sound that travels through air) measurements. It is commonly a hand-held instrument with a microphone . The diaphragm of the microphone responds to changes in air pressure caused by sound waves. That is why the instrument is sometimes referred to as a Sound Pressure Level (SPL) Meter. This movement of the diaphragm, i.e. the sound pressure deviation (pascal Pa), is converted into an electrical signal ( volts V ). SPL – Sound Pressure Level (in dBA ) below is instrument that we are using at test bay SWL – Sound Power Level (in watt) Sound power or acoustic power is the rate at which sound energy is emitted, reflected, transmitted or received, per unit time. The SI unit of sound power is the watt (W). It is the power of the sound force on a surface of the me...

Case Study 4 Title: Positive Displacement Pump Faulty Findings & Observation: 1. All parts were in good condition upon dismantling pump from the skid. 2. Technician discovered that the plug near air inlet was not unplugged and it needed to be replaced with 1/4" muffler for this model ( XPS1530/SSAAA/TWS/TF/STF ) 3. Pump only achieved 50% when it was assembled to the skid. Possible causes on the findings and observations: 1. Spill stop having 3/4" pneumatic actuator valve gas restricted air flow significantly. 2. Pump eventually achieved 100% performance by changing 1" filter regulator. Solution and Conclusion: 1. Diaphragm pump air inlet and outlet can't be downsized, it has to be one size up for all kind of fittings. centre block was not unplugged  centre block has been unplugged. rigid pipe was installed, inflexibility can cause fitting or muffler plate to crack. 3/4" fittings was installed on air discharge ...

Case Study 3 Title:  Pump leaking from stuffing box  Findings & Observation: 1. Water  leaking from stuffing box when outlet valve partially closed. 2. Pump back plate was assembled at wrong position (flush plan 01) Possible causes on the findings and observations: 1.  upon the reassembly of pump , pump run with fully open outlet valve – no leaking found. When  outlet valve was  partially closed at 4.5 barg, the stuffing box started to leaking very badly. 2.  During priming stage, we suspect the pump inlet pipe could be too long and it's without a foot valve. (water is muddy and can’t see much) 3. Technician  found shaft protection sleeve loose – easy to withdraw from pump shaft. The shaft protection sleeve O ring likely to be worn or broken. Solution and Conclusion: Recommendations: 1. Replace shaft sleeve O ring as factory has wrongly installed a slightly smaller size of O ring that results in p...

Case Study 2 Title: Pump performing below expectation Findings & Observation: 1.  Pump  cannot achieve it duty point. Possible causes on the findings and observations: 1. Filter regulator under size 2. Air hose under size 3. Needle valve under size Solution and Conclusion: 1. Connect to 3/4" filter regulator achieve 80% of actual flow rate and pressure. 2. Connect to 3/4" filter and needle valve can only meet 30% of actual flow rate and pressure. 3. Connect  test bay  1" air hose direct to diaphragm Pump can meet the flow rate and pressure. Recommendations: 1. Up size the filter regulator from 3/4" to 1" 2. Remove the needle valve. The needle valve only have 6mm orifice size on air outlet. It restricted the air output. 3. Up size the air hose from 3/4" to 1" Pump install with 3/4' air hose Pump with 3/4" Filter regulator & needle valve Pump with 3/4" Filter r...

Case Study 1 Title: Pump leaking through mechanical seal Medium: Water with unknown chemical treatment Findings & Observation: Feedback on pump leaking due to the faulty of mechanical seal. Possible causes on the findings and observations: 1. Pump could be out of alignment, cavitation, and chemical corrosion to mechanical seal or incompatible elastomer, or foreign object entering seal stuffing box chamber. 2. Technician discovered that the impeller and back casing (with pin holes and sign of corrosion) damaged by chemical corrosion. Also found the impeller and back casing were having cavitation of damaged. 3. Pump bearing was malfunctioning due to mechanical seal leaking and water got into bearing causing bearing to fail. Meanwhile the pump shaft also damaged due to bearing malfunctioning and  unbalanced  impeller  (due to chemical corrosion or cavitation). Solution and Conclusion: 1. Replace mechanical seal, shaft, bearing, im...