machinery diagnostics Archives - Acoem USA

Static, Couple, and Dynamic Unbalance

According to the International Organization for Standardization (ISO), unbalance is “that condition which exists in a rotor when the vibratory force or motion is imparted to bearings as a result of centrifugal forces”. In other words, unbalance is an unequal weight distribution of a rotor around its rotating centerline. The rotating centerline or rotational axis…

Using a Strobe Light to Verify RPM

Knowing the correct rotational speed is critical when performing machinery diagnostics. A strobe light can be an excellent tool for determining speed. Look for a unique mark such as a keyway, piece of tape, etc. to use as a reference. You will adjust the flash rate of the strobe light until you only see one…

How Vibration is Measured (Cont.): Vibration Level Charts, ISO Values, and More

In Part 1 of How Vibration is Measured, we discussed how equipment vibration is measured. An accelerometer mounted to a machine bearing vibrates. This vibration in the accelerometer produces a voltage. The amount of movement of the accelerometer determines the amount of voltage, and the severity. The frequency of the voltage (how many times per…

Using the Acoem Bearing Defender as a Lubrication Tool

Co-author, Stan Riddle. Lubricating bearings on a regular PM schedule has some inherent problems-mainly, how do you know if a bearing needs lubricating or not? If the bearing seal is not compromised, grease should stay in the bearing, and provide lubrication for a long time. But if the seal is blown, the bearing will require…

Root Causes of Machinery Failure

As maintenance and reliability professionals we have a tremendous responsibility to keep the machines in our facilities up and running. As the entire world navigates through this pandemic, water, power, food, medicine and many other essentials have continued to be provided. Having the necessary skills and knowledge is critical to ensuring that we are able…

Double or Tandem Mechanical Seal?

Although it is not the millwright or mechanics responsibility to specify mechanical seal applications, it is a good idea to have a basic understanding of their purpose. This blog will give the basics of double and tandem mechanical seals. The double mechanical seal uses two mechanical seals (an inboard and outboard seal). They can…

Pre-Alignment with the RT-300

ACOEM-VibrAlign has shared over 100 separate blog posts and over 1 million YouTube views on Pre-Alignment. Thus, we can all agree it is an important topic and the key to a successful precision shaft alignment job. No matter if you are using a Straight Edge, Dial Indicators, or the latest and greatest Laser Shaft Alignment…

Generating Global and Special Reports in the NEST

Once you have moved your data back into the Nest, after a Route has been collected, you may want to provide a report or reports to different parts of an organization. The Nest has several ways of generating a couple different types of custom reports. For your discussion we will focus on a global report…

Identify Gaps in Knowledge with the Smart Machine Checker!

At a recent Fixturlaser Smart Machine Checker (SMC) training class, one particular pump came up during the discussions. This pump has been “a problem child” for years. It had been rebuilt recently by one of the class attendees. The mechanic had rebuilt the pump “just as it had come apart” and was certain the impeller…

RESOURCES

I read that Albert Einstein once said, “I don’t need to know everything, I just need to know where to find it when I need it.” If one did some research, that may not necessarily be true. However, if a question comes up, it’s always helpful to have resources to refer to. When it comes…

Mechanical Looseness Identification

A common vibration signature on equipment is looseness. There are two types of looseness: structural/fastener, fit between rotating components. For this discussion, we will focus on structural and fastener looseness. Typically, it is highly directional, occurs at 1xRPM, and will look similar to this spectrum. In this case, the vibration was confined to the vertical…

Permanent Mounted Sensors

At the wrap up of a recent Hawk/SMC class the discussion was around what rotating assets to collect vibration data on going forward. The conversation quickly turned to a few keys assets that had the ability to impact large percentages of the downstream processes. The area technicians said that even though the machine was very…

Calculating VFD Motor Speed

When using the Fixturlaser Smart Machine Checker (SMC) or any of VibrAlign’s Condition Monitoring Tools, there are typically only two variables you need to know for an accurate diagnosis of your machine. You need the horsepower of the motor and the correct rotating speed. This information will usually be stamped on the motor data plate. …

The Soft Foot Primer (Part 2) Vibration and Alignment Problems Related to Soft Foot

Most industrial maintenance mechanics who are involved with precision shaft alignment are familiar with the phenomenon of soft foot. From an alignment standpoint, soft foot causes: Changes in alignment values, between when the hold down bolts are loose, and when they are tight. Non-repeatability in alignment measurements, especially if the bolts are not tightened in…

Stupid Questions

While on the road conducting precision shaft alignment training I run across a wide range of skill level. It is not uncommon to have a lot of questions. I like it when there are questions, that is usually an indication that the trainees are engaged. It is also not uncommon that a question starts with,…