The start-up phase of a major industrial construction project is a critical moment that determines whether the invested time, effort, and resources will result in an optimally functioning system. One crucial aspect often overlooked is the pre-operational cleaning of rotating equipment piping and systems. This process is essential for ensuring smooth operations and preventing costly delays or failures during or after start-up.
Understanding Rotating Equipment
Rotating equipment plays a vital role in industrial systems, moving liquids, solids, or gases through a complex network of components. These systems typically include:
- Drivers (turbines, motors, internal combustion engines)
- Driven components (compressors, power generators, pumps)
- Transmission devices (gears, clutches, couplings)
- Auxiliary equipment (lubrication systems and associated tanks, cooling systems, buffer gas systems)
The Importance of Pre-Operational Cleaning
After mechanical installation of piping and inline equipment, various contaminants and construction debris can remain in the system. These can range from large objects like tools and personal protective equipment to metal shavings, and microscopic particles. The presence of these contaminants can lead to several issues:
- Visible debris – Large objects left in the system can cause immediate damage or blockages.
- Small particles – Even particles measuring millimeters or fractions of an inch can cause significant damage when propelled by high-speed streams.
- Microscopic contaminants – Particles in the sub-micron to 20 µm range can lead to premature wear of bearings, mechanical seals, valves, and gear pumps.
While many systems include in-line strainers or filters, these alone are often insufficient to provide adequate protection. They may quickly clog during initial start-up due to the large number of particles or unexpected objects in the system.
Benefits of Pre-Operational Cleaning
Implementing a proper pre-operational cleaning process during pre-commissioning or commissioning can yield numerous benefits:
- Unexpected equipment outage and loss of revenue
- Increased lifespan of filters, strainers, and lubrication oil
- Reduced friction losses in pipes
- Reduced and/or inhibited corrosion
- Improved heat transfer in exchangers
- Enhanced product quality in some cases (e.g., reduced moisture in fuels or bio-fouling in potable water lines)
Cleaning Methods
Several methods can be employed for pre-operational cleaning, depending on the specific requirements of the system:
- Pigging – Used to remove large objects, water, product residues, rust, and mill scale.
- Air Blowing – Commonly used for cleaning pipes that feed turbines, often following manufacturer-specific requirements.
- Water Flush Cleaning – A simple method for removing large objects, though it may be limited by water availability or disposal difficulties.
- Chemical Cleaning – Includes processes like degreasing, oxygen service cleaning, descaling, pickling and passivation.
- High Velocity Oil Flushing –Removes microscopic particles in lubricating or hydraulic seal oil systems and can help eliminate moisture mixed with the oil.
- Mechanical Polishing & Electropolishing – Surface reconditioning techniques that provide a smooth, featureless surface on stainless alloys.
Pre-operational cleaning of rotating equipment and systems is a crucial step in ensuring a successful start-up and optimal long-term performance. By removing contaminants and debris, this process can prevent costly failures, reduce maintenance needs, and extend the lifespan of critical components. Investing in proper cleaning procedures before commissioning can save significant time and resources in the long run, making it an essential consideration for any major industrial project.
