What are the key steps and checks for performing a soft foot correction?

Understanding the environment that this machine lives in will help you determine the best base material to use. “Rust Jacking” is a common problem in wet environments, thermal expansion is also a common problem in high heat environments. You could start off with a good alignment that could deteriorate over a surprisingly short period of time. This is a cause for premature failures in coupled machines and thus a cause for re-work or failure maintenance.

Keep in mind that in the early stages of this task it is best to start with tools that are less accurate. Using highly accurate tools for a rough levelling can leave you chasing your tail. Get it close first, it takes less time and helps find big mistakes that can be confusing with highly accurate equipment.

It's important to perform rough alignment before measuring the soft foot. Machines with sever angular misalignment can give indications of a bent soft foot. or Coupling strain may induce a soft foot.

The soft-foot check must be carried out without piping connected to the equipment. However, after piping connections, check for Induced Soft-foot. Ensure it is performed during the final alignment on each foot of the equipment. All hold-down bolts must be tightened for the specified torque by the equipment vendor. Measurement must be taken as close as possible to the foot’s hold-down bolt location. Often equipment trains have hold-down feet that are not accessible with a dial indicator and still have room to apply a wrench to a hold-down bolt. In such a scenario, the soft-foot checks should be carried out by checking shaft end movement in both the vertical and horizontal direction.

Maximum movement must not exceed 0.05 mm at each foot. In certain applications with high thermal growth anticipated, higher soft-foot values may be acceptable. Under the running conditions, this soft-foot condition will be compensated under thermal growth. The maximum allowed soft-foot value in high-temperature applications, taking into consideration thermal growth, can vary depending on the specific equipment, its design, and the industry standards or guidelines being followed. There is no universally fixed value for maximum soft-foot allowances in high-temperature situations because it depends on factors such as the material, design, and operating conditions of the equipment.

Record all your findings as you progress. This is important as it may help you find errors or defend your work after completion. It’s also necessary for many sites to have proof of good installation and how that was achieved.

Neglecting soft-foot issues or carelessness can lead to various consequences. While some are mentioned here, it's essential to understand that the impacts go beyond: Shortened Equipment Life: Persistent soft-foot issues wear critical components, reducing equipment lifespan. Higher Maintenance Costs: Misalignment causes frequent breakdowns, increasing operational expenses. Energy Inefficiency: Misaligned equipment consumes more energy, raising costs and reducing efficiency. Safety Hazards: Vibrations and misalignment endanger personnel, potentially causing accidents. Production Disruptions: Unplanned downtime disrupts productivity and profitability.

Many environments may be loud, hot and have varying levels of vibration. Regardless, the job needs to be done with as much accuracy as possible. Note the undesirable issues as you progress, and ensure these note are communicated to your supervisor or the site coordinator. If you can, give solutions to reduce or eliminate these problems, a client or supervisor would be happy for the added insight.