Corrosion Under Pipe Supports
Updated: May 19, 2021
Corrosion Under Pipe Supports (CUPS), also known as pipe Touchpoint Corrosion (TPC) is a phenomena that all petrochemical facilities must address in order to maintain their piping infrastructure.
CUPS is caused by water entrapment which over time results in corrosion that reduces the wall thickness at the touchpoint and eventually compromises the integrity of the piping system.
Accessing the touchpoints is critical for performing inspection and remediation work and often requires lifting the pipes in order to expose the damaged area and provide access.
Lifting pipes from their supports presents its own risks to both personnel and equipment. Lifting causes the pipe to bend which adds stress to the system and changes the pipes resultant load distribution on the supporting structures. Pipes can also be lifted while in-service introducing risks to personnel and environment such as loss of containment of product.
Inspection and remediation are primarily reactive activities since the number of pipe touchpoints in a single facility number in the hundreds of thousands. This makes it costly to proactively inspect each location at required intervals so failures have become commonplace and often result in costly shutdowns.
Performing repairs under time critical conditions can force operators to rely on unsafe lifting methods such as chain falls and cranes which can be costly, unsafe and done without consideration of pipe stresses, load distributions on supporting structures and lifting capacities. These methods create suspended loads which are unsafe to work beneath and only lift individual pipes at a time which are unproductive for applications where entire pipe racks must be lifted for inspections and re-coating applications, for example.
Key features of Ovolifts’ pipe lifting technology that address these issues are:
Lift Multiple Pipes – Ovolifts jacks can lift single pipes or multiple pipes across multiple supporting beams in a single lifting operation, depending on the requirements.
Static Structure Lockout – The pipe rack jacks are designed with a locking mechanism which eliminates a suspended load and effectively creates a temporary pipe support which is safe to leave in place for extended periods of time.
Remote Lifting – The jacks are hydraulically activated allowing personnel to stand at a safe distance away from the equipment during the critical lifting operation.
Engineered – Every lift is engineered with consideration to pipe stresses, load distributions across multiple supports and lifting capacities to determine appropriate lifting configurations and procedures to execute a safe and successful lift.
On-Stream Experience – Years of experience with numerous projects completed on live equipment and without incident stands testament to our expertise in this niche service line.
Other than general inspection and remediation work, there are many other situations which necessitate lifting a pipe:
Liquid Pipe Hammer - These events can damage the supporting pipe shoe, move the pipe out of position or both. Lifting provides access to the shoe for repairs and allows operators to relocate the pipes horizontally to its original position.
Instillation of Pipe Wraps or Enclosures – Significant wall loss may require an enclosure to reinforce the pipe at the support location and restore integrity.
Repairing or Replacing The Support – Supporting beams can be made from various materials such as concrete or metal and can be located in multi-level racks or on ground level. Damage to the supports can compromise the integrity of the entire piping system and to do repairs or replace the supports the pipes must be lifted from existing adjacent supports or by temporary supports. Entire pipe racks can be replaced using this method.
To learn more about Engineered Line Lifting visit: www.ovolifts.com