Last month we reviewed the pump selection criteria for a closed loop circulation system (Vp-Vf). This month we will take a look at a similar application that adds some elevation to the equation.
When measuring vibration, one of the most important factors in obtaining accurate information involves selecting the proper vibration transducer. Selecting the wrong vibration transducer can yield results that are misleading or, worse, mask a problem.
PWM inverters introduce motor shaft voltages and bearing currents. The bearing damage in inverter-driven motors is mainly caused by the shaft voltage and bearing currents created by the common-mode voltage and its sharp edges . All inverters generate common-mode voltages relative to the power source ground that cause coupling currents through the parasitic capacitances inside the motor. The main source of bearing currents is the capacitance-coupling currents that return via the motor bearings back to the ground.
When the City of Delaware, Ohio, expanded its wastewater treatment plant, it looked to increase more than just capacity. It also wanted to increase its efficiency and automation capabilities to benefit the plant's operators and taxpayers.
Mechanical pressure gauges, which require no external power, provide an affordable and reliable source of accurate pressure measurement. Using the criteria below can help maximize gauge life.
Sensors and automation passively participate in our everyday lives to improve comfort, add safety and reliability, and increase the efficiency of needed products and services.
Changing traditional industry ways of thinking can help usher in the plant of the future.
In only a couple of years, the focus on energy efficiency has gone from blurred to steely-eyed. Green business practice is now a necessity, and organizations must find the best way to transition to this new reality. There are many opinions and approaches on "how we get there," and each one will have its own merits. A journey of a thousand miles starts with a single step, and making the right steps in the beginning will hasten the achievement of energy efficient goals.
The installation of an AC drive with an advanced software tool has dramatically cut call-outs for blockages at an Irish county council pumping station.
Of the technologies available for condition monitoring of rotating equipment, the quickest return on investment is from vibration analysis. For the novice, vibration data seems complex and is generally difficult to assess compared to other techniques. Once trained, however, the novice can recognize the patterns and diagnose a machine problem.
Electric drives are used in various applications in the oil and gas industry for varying motor speeds driving critical components, including pumps, fans and compressors.
Although the use of transmitters in pressure measurement is growing, mechanical pressure gauges are still used on most systems as local pressure display to back up electrical readings. The selection and installation of these gauges can be difficult in certain locations. Harsh conditions that can require special consideration include vibration, pressure pulsation, overpressure, corrosive media and extreme process and ambient temperatures. This article is designed to address harsh conditions with best practice recommendations to extend gauge life and provide for the safest installation possible.
How a monitoring alarm system with control and shutdown capabilities prevented costly pump damage and environmental hazards and made the job of the pump operator safer and easier.
One of the major contributors to unbalance in rotating machinery is eccentricity. When we disassemble parts, we must also reassemble them. Even if the reassembly requires heating to shrink-fit the elements back together, we probably balanced them in a balancing machine where tolerances due to fit-up on mandrels or roundness of journals may possibly far exceed the heavy spot tolerances that the target standard of balance allows.
Pumps are sent to rebuilding and remanufacturing companies because buying new can be expensive and require long lead times. For instance, a 39 in diameter, 1,000 lb bronze impeller may cost $28,000 and take many weeks to deliver. In these cases, the impellers involved in an overhaul are often built back up to the required specifications and rebalanced.
Even when a redundant pumping system is in place, it can be advisable to monitor the condition of the operating units in critical applications where maintaining production depends on motor-pump reliability.
A dangerous misconception exists regarding the "Arc Rating" of infrared (IR) windows or viewing panes. Many reliability and maintenance professionals are under the impression that an IR window will protect them in the event of an arc blast. Others believe that installing IR windows will turn non-arc-rated switchgear or electrical equipment into "arc-rated" cabinets. Neither is true. Both misconceptions need to be corrected because they present safety concerns.
Interpretation of equipment clues can help diagnose problems before failure occurs
Many items must be considered when designing pump station control systems with power requirements, level control method and control panel location often among the most important.
Joseph Gallo Farms in Atwater, Calif., uses captured methane gas from its 5,000 dairy cows to run up to 50 percent of the electricity for its cheese factory.
A variable frequency drive (VFD) can be a valuable asset in reducing the life cycle costs in certain types of pumping applications. The traditional method of motor control in pumping applications is a low cost mechanical starter, which is essentially a large switch with a built-in motor protection device known as a thermal overload relay. A conscious decision to reduce upfront costs by using a mechanical starter may result in higher energy consumption, excessive component wear and poor power quality.