Rock Products

SEP 2018

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42 • ROCK products • September 2018 EQUIPMENT & TECHNOLOGY PUMPS & MOTORS probe located in the pumps mechanical seal chamber. A seal failure circuit (or moisture detec- tion circuit) is designed to monitor the amount of moisture within the mechan- ical chamber. Once a critical level of moisture has entered the mechanical seal chamber, an alarm is initiated. This early warning can allow the operator to schedule repair and inspection of the pump, preventing costly catastrophic failure and unscheduled downtime. If a seal minder alarm is initiated, a sample of the seal chamber oil should be taken to verify the amount of water/ contaminates present in the mechani- cal seal chamber. The seal should be replaced if the fluid removed is milky or shows a high level of water/ contaminants. Various types of preventive alarms can be installed on a submersible pump and the associated control system. These include motor temperature sensor alarms, high fluid level alarms, over and under current alarms, just to name a few. The requirements of each application will determine the proper system alarming that is beneficial for a given application. 3. Pressure and Flow Checks Consistent hydraulic performance of a pump is critical to an operation. A submersible pump should perform at the same flow and pressure output that was measured and noted in the start-up report. A pressure gauge should be located as close to the piping discharge as possi- ble. The pressure gauge reading will indicate the psi (pounds per square inch) performance level of the pump in the piping system and should stay the same as long as no changes have occurred in the pumping system. If there is a discrepancy between cur- rent operation and the start-up report, check for possible hydraulic issues. Clogging can occur within the pipes, check valves can stick, control valve set- tings can be changed, or critical piping system changes may have been made. Changes in the fluid entering the sump basin can also change the performance of a submersible pump. Excessive solids, fluid specific gravity, and chem- ical changes are just a few parameters that can affect a submersible pump's performance. 4. Visual Inspection During preventative maintenance, the submersible pump should be pulled for a visual inspection. • Are there debris jammed in the suc- tion inlet, pump housing or stuck around the impeller? •  Is the pump showing any signs of physical damage? •  Are solids like milk fats, animal fats or sticky materials adhered to the pumping elements? • Have critical pumping elements seen physical damage, chemical attack or erosion? Exterior surfaces should be checked for dents, corrosion or abrasion. The electrical power and sensor cables should be free of cuts or frays and be properly supported by the strain relief mechanism. The sump basin should be checked for excessive solids build up. Call Your Local Distributor Most routine maintenance and repairs can be performed in-house by a quali- fied maintenance technician. However, when there has been a change in pump performance, and preventative mainte- nance checks do not define a clear path to a root cause solution, assistance may be required from your local distributor. These may include: •  Megger testing to check for insulation faults to ground. •  Winding resistance check to con- firm resistance balance and confirm no motor winding degradation has occurred. •  Damage to critical pump components. – Impeller vanes and shredding components. – Suction cover and pump housing. – Power/sensor cable and the associated sealing systems. – Motor housing, pump cover, lifting devices. •  Any unexplained change in pump performance (flow, pressure, amp draw, etc.) With proper periodic maintenance, including checking the amp draw, pump function and routine visual inspection, a quality submersible pump will last for years without degradation. For more than 35 years, BJM Pumps and its highly qualified expert distributors have provided reliable, long-lasting pumps for industries ranging from food and beverage to power generation and utilities. Customers receive unparal- leled service from specification through installation and continued support throughout the life of the pump. BJM Pumps,

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