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Showing posts from November, 2021

What is ISFD Bearings, how it works?

What is the ISFD Bearings? Integral squeeze film damper  ( ISFD) technology, a Flexure Pivot tilt pad journal bearing, provides precise stiffness and damping to increase the dynamic stability of the rotor/bearing system. Reduce Dynamic Bearing Forces ISFD technology reduces the dynamic load that is transmitted to the bearings, which reduces pedestal vibration and increases bearing life, particularly for rolling element bearings. For fluid film bearings, the technology can mitigate pivot wear and reduce babbitt fatigue. Decrease Unbalance Sensitivity ISFD technology helps reduce the sensitivity to unbalance, protecting impellers and seals from rubbing and increasing maintenance intervals. Versatile Design The ISFD design, manufactured through electrical discharge machining (EDM), can integrate the bearing and damper into one unit for a space-saving solution suitable for new and retrofit installations. ISFD technology can be used with tilt pad, Flexure Pivot tilt pad, fixed profile or ro

Waukesha bearings: Fluid Film Bearings, Active Magnetic Bearings Systems, and Damper and Seal Technologies

Waukesha Bearings provides custom-engineered hydrodynamic fluid film bearings, active magnetic bearings systems, and damper and seal technologies for turbomachinery across the oil & gas, power generation, marine, and industrial markets. Engineers apply design codes and predictive tools to tailor thrust, journal, or combination bearings to achieve optimum performance across the machine operating range. The Waukesha Bearings Maxalign tilting pad journal bearing, for example, features a specialized ball and socket pivot, along with Directed Lubrication and trailing edge cooling to increase reliability and reduce power loss for rotating equipment with shaft diameters greater than 300 mm. Engineers optimize the bearing size and pad materials and tailor insulation, hydrostatic jacking, and instrumentation according to requirements. “Each application is unique so we design each bearing to meet performance requirements, whether they are tilt pad or fixed profile, babbitt, bronze, polym


In-line inspection (ILI) of pipelines has established itself as the most efficient tool for evaluating the condition of a pipeline and an indispensable part of pipeline integrity management. Historically, there have been two major technologies used in in-line inspection for corrosion, the magnetic flux leakage (MFL) and ultrasonics (UT), each having their distinct properties and fields of application.  Ultrasonic (UT) ILI has always provided unique quality of information about the pipelines, rendering highest accuracy and tightest measurement tolerances. In the 1990s ultrasonic tools for detection of cracks have become available. Ultrasonic measurement principle: ultrasonic transducer slides along the internal surface of the  pipe wall measuring distance to the wall and the wall thickness (top), yielding the stand-off and the wall  thickness (bottom two B-scans) Ultrasonic (UT) based In Line Inspection tools for all types of liquid filled pipelines. This includes Ultrasonic MultiChan

Troubleshooting Pipeline Steam Condensate

One day an engineering lecturer at school discussed an accident at a nuclear power station. Seawater had entered the cooling pipes of the reactor. He asked the students what would happen in such a situation. A Dean’s Honor-List student answered that neutron flux from the reactor would irradiate the sodium ions in the seawater salt molecules to create a short-lived isotope of sodium. This isotope would emit low-intensity alpha radiation which lodges in the interstices of the ferrous lattices of the steel alloys of the pipes, creating hot spots or fractures, leading to escape of radioactive seawater to the river. No, the lecturer replied, the pipes will rust. In troubleshooting, then, it is best to frst suspect the obvious. Why make things more complicated than they really are? Recognizing that there is an overflowing sink and turning off the water, for example, can save a lot of time that might otherwise be spent trying to mop up the floor. To troubleshoot problems, it is necessary to be

17 Maintenance KPIs

Maintenance KPIs are performance metrics that help you measure how effective your overall maintenance process works. You can use them to track the progress of your individual maintenance crews, as well as the overall performance of your entire organization.   These KPIs will be utilized across the site’s Maintenance Departments: LTIFR,  Lost Time Injury Frequency Rate  (both production and maintenance) Maintenance Cost per Hour vs. Budget Cost of Quality Maintenance Effectiveness Maintenance Efficiency Mean Time Between Failure (MTBF) Mean Time to Repair (MTTR) Preventive Inspection Effectiveness Ratio of Preventive to Breakdown Maintenance Backlog % Scheduled Man Hours Planned % Schedule Compliance % Planning Effectiveness % Man Hours Available % Rework % Failures Investigated MIP Process Effectiveness  (MIP = Management Improvement Program). How to calculate these KPIs, please read this document:

Boiler Systems: Troubles in Operation and Their Causes

Definition of boiler systems Boiler system is a system that is used to heat water and to generate required steam or hot water. The boiler system is generally composed of the following units: (a) Feedwater treatment unit: demineralizer, etc. In case that the raw water is supplied from a river, a lake and so on, the raw water treatment units (clarifier, filter,etc.) are required.  (b) Feedwater line, (c) Deaerator, (d) Boiler including preheater, superheater and desuperheater, (e) Steam and condensate line, (f) Condensate treatment unit, (g) Wastewater treatment unit, (g) Chemical injection unit. Classification of boilers by their structures (1) Cylindrical boilers (pressure : below 20 kgf/cm 2 ) : (a) Vertical boilers, (b) Flue-tube boilers, (c) Fire-tube boilers, (d) Fire and flue-tube boilers. (2) Water-tube boilers : (a) Natural circulation boilers (pressure : low to high), (b) Forced circulation boilers (pressure : low to high), (c) Once-through boilers (pressure : above 75 kgf/cm 2

How to Solving Fatigue Failures: Reduce or Eliminate the Cyclic Stress and Design to Improve Endurance Limit

Fatigue is a failure mode that every manufacturing plant will experience at some point and can become chronic if not solved. While understanding fatigue has advanced since its inception in the early 1800s, there are still some misunderstandings in manufacturing in solving these failures. A characteristic of fatigue failures is stress, which is typically below the yield strength of the material. This is what makes fatigue a silent killer. Fatigue occurs on a part that is subjected to alternating or cyclic stress. Cyclic stress can cause failure after a certain number of cycles. Fatigue becomes a failure mode when cracks initiate where stresses have concentrated on the part. When solving fatigue failures, there are two key areas on which to focus the analysis: External forces that cause the cyclic stress and component design that reduces the endurance limit of the material. It is in one or both of these areas where the solution to fatigue failures can be found. So, let’s take a closer lo

How to clean superalloy parts? brazing technique removes oxides in deep, narrow cracks

Investment cast parts used in modern gas turbines are made of expensive superalloys that can withstand extreme thermal, mechanical and chemical loads experienced by hot gas path components. Parts with hundreds of thousands of service hours, however, become severely oxidized. To improve efficiency and reduce the risk of unscheduled outages, these parts must either be periodically refurbished using a brazing repair process or replaced. To facilitate brazing repair, all oxidation, sulfidation and hot corrosion must be removed from surfaces, cooling passages and deep, narrow cracks. Oxide scale typically forms on the mating faces of cracks that occur in hot gas path areas. These cracks become packed full of scale. It is the goal of the service shop to repair these components by filling the cracks with a braze alloy. Unfortunately, braze alloy cannot flow into cracks filled with oxide scale. Figure 1: By varying the pressure between positive, negative, and atmospheric levels, the Dynamic FI