Generic selectors
Exact matches only
Search in title
Search in content
Post Type Selectors

It’s All About That Base!

Maintenance & Reliability
Base millwright

It’s All About That Base!

BaseOne of the “foundations” (pun intended) of good millwright work is the machine is only as good as the base it sits on. When I started out as a millwright, the accepted practice was:

  • The base should have sufficient mass to dampen vibration, absorb shock, and stabilize any forces from piping, duct, conveyors, or any other accessory components.
  • The mass of the base should be at least 3 times the mass of the machine that it supports. In other words, if the machine weighs 1000 pounds, there should be 3000 pounds of base, to include base, frame, soleplate, grout/concrete.
  • Unless the base sits upon isolators per design criteria, the base should be anchored with steel J-hook bolting, or some other attaching mechanism, to the floor.

If you see a machine with this kind of base today, odds are good that it was installed 30+ years ago. There are many various specifications for bases from organizations like API. Many companies use specifications given by their engineering design groups. But the actual installers may not know what the specifications are, and the commissioning engineer may not check it. Shortcuts are sometimes taken.

So that’s that got to do with alignment? A lot! Because you can’t align a moving target!

If the frame is not sufficiently rigid to prevent movement of the machine components during operation, the relative positions of the driving and driven machines can change. If the base has insufficient mass, the machines can move. If the base isn’t lagged into the floor, it can move. If piping and duct isn’t supported with suitable hangers, the machines must support their loads.

Simply stated, may not be able to perform a precision alignment on machines that sit on bad bases. And even if you get a great alignment, it could change.

Related Articles

Related Whitepapers

Bearing Protection Best Practices

Electro Static Technology (EST, AEGIS®) guarantees that AC induction motor bearings will not fail from electrical fluting damage when AEGIS Shaft Grounding Rings have been…

Positive Displacement Pumps Best Suited For Liquid-Transfer Applications

Pumping applications can range from being simple – fluid transferring operations that move product from one tank, container or truck to another – to complex…

Accurately Predict Transient Fluid Forces in Piping Systems, Part 2: Applications

Part 1 of this series discussed in detail how to accurately calculate the reactions induced by pressure transients that travel at acoustic velocity in either…

Accurately Predict Transient Fluid Forces in Piping Systems, Part 1: Fundamentals

Changes in the operation of piping systems – like valve closures or pump starts – propagate pressure waves that travel at acoustic velocity throughout the…


Leave a Reply

Your email address will not be published. Required fields are marked *

Join the #PumpTalk Community

By submitting this form, you are consenting to receive marketing emails from: Empowering Pumps & Equipment, 2205-C 7th Street, Tuscaloosa, AL, 35401, You can revoke your consent to receive emails at any time by using the SafeUnsubscribe® link, found at the bottom of every email. Emails are serviced by Constant Contact