Posts Tagged ‘Alignment tolerances’
Aligned at the Factory – Realigned in the Field￼
Recently I came across a new pump skid where an alignment check was performed after installation during new construction. Even though it did not have much run time there were already telltale signs of misalignment as indicated by the coupling insert dust on the base. The new pump skid came aligned from the factory: A…Read More
How Do You Align Machinery on a Flexible Base?
This is as much a title for a blog as it is a question. One our Technical Trainers once stated that to align rotating machinery, they must first be alignable. What is meant in part by this is that when we have a collinear tolerance of 0.5mil /1” angularity and 2.0 mils offset, the machines…Read More
Know Your Alignment Tolerance
VibrAlign and Fixturlaser have done what we can to make the precision shaft alignment process quicker and easier for the end user of our tools. To assist maintenance personnel during an alignment a tolerance table “pops up” on the display unit screen (of our tools) when entering dimensions for the machines being aligned. The tolerances…Read More
Setting Tolerances in Fixturlaser Shaft Alignment Tools
Fixturlaser Shaft Alignment Tools come pre-programmed with generally accepted industry tolerances for electric motor driven machinery. These tolerances are based on the motor RPM and will give you an “endpoint” in the alignment process (based on the measured offset and angular misalignment at the center point of the coupling in both the vertical and horizontal…Read More
Just Get It Running, We’ll Fix It Later!
Sound familiar? I can’t tell you how many times I personally have heard this over the years. I am sure many of you have as well. The issue is, scheduled downtime seems to be put on the back burner so to speak, to meet production goals. And as it has become all too familiar,…Read More
Are Shims Causing a Soft Foot Issue?
One of the many things I love about my job is the numerous challenges we face during the field alignment portion of our Precision Shaft Alignment Training. Prior to the training, there were some repeatability issues when attempting to perform a precision alignment on this piece of equipment. One of the main causes of non-repeatability…Read More
You Can’t Perform Precision Alignment on Un-precise “Stuff”!
Alan Garbers with Johnson Controls International contacted me regarding an alignment problem, and asked for my advice. Here is a condensed version of his email. A client rents portable chillers, and related equipment. They built a 125HP portable pump skid with a Bell & Gossett pump on a VFD. I was there to commission the…Read More
Understanding Spacer Shaft Alignment
The majority of precision shaft alignments are relatively close coupled where there are only a couple of inches between the shaft ends of the driver and driven elements. Close coupled alignment quality is traditionally displayed as angle (driver to driven) and offset (at the center of the coupling). The question is what do you do…Read More
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,…Read More
Whether instructing a training class for precision shaft alignment or geometric measurements, the topic of machine specifications frequently comes up. Specifications such as shaft alignment tolerances, bolt torque values, frame or base flatness requirements and the frequency of verification of these specifications are typical of what is asked. There are general industry specifications such as…Read More
Fire Pump Maintenance
Fire Pumps are a critical safety item in facilities across the world. Their purpose is to make sure a building has enough water pressure in case of a fire emergency. Of course, the hope is that they are never needed but if they are they need to perform reliably. Fire Pumps are typically tested on…Read More
Pipe Strain Was the Issue
Have you ever struggled with a precision shaft alignment, even though you did everything right? (Preformed the pre-alignment steps, controlled backlash, etc., etc.) So, what was different? Maybe it was pipe strain. An alignment check of a new installation of a 40 HP, 3600 RPM motor/pump revealed the vertical angular misalignment was 3.2 times the…Read More
Is there such a thing as “Too Good” of a Precision Shaft Alignment?
This question comes up frequently in our Shaft Alignment Best Practices training classes. The result screens below both show two different aligned machines meeting 3600 tolerances. The question is; is one better than the other? There has been a lot of discussion about this very topic. The theories are abundant and points of view…Read More
Coupling Tolerances vs. Shaft Alignment Tolerances, What’s The Difference?
Plenty! This question still comes up fairly often in our training classes. If you look any of the coupling manufactures installation instructions there is a chart for the maximum allowable misalignment based on the coupling size. These tolerances are for the coupling, what about the machines the coupling connects? Shaft alignment tolerances are more about…Read More
Repeatability vs. Desired Outcome in Shaft Alignment, Part 2
In my last post, we looked some reasons for non repeatable, or when “two plus two doesn’t equal four”. This time, let’s think about when we don’t get an expected or desired outcome when we shim and move. Think of it as when “two minus two doesn’t equal zero.” You may perform an alignment measurement,…Read More