Importance of Pipe Stress Analysis in Piping System

As a piping engineer, you know there is a lot more to pipe design than just planning pipeline layout. Pipes may look static but can be surprisingly dynamic. The change in the potential loads leads to shift, cause harm, damage and other effects in the pipes. And suppose the materials used in the piping system are hazardous. In that case, there can be an adverse effect on people’s health and equipment in your plant.

It is normal to experience piping related challenges in industries. A pipe stress analysis can help predict stresses in piping and loads on equipment to identify the issue and make a safe and long-term fix.

Importance of Pipe Flexibility and Rigidity

Flexibility: The pipe stress analysis is a balancing act between flexibility and rigidity. It’s vital to design the piping system to be firm and elastic depending on the potential loads. Thermal expansion is the primary reason to provide flexibility in piping design. Pipes expand when the temperature rises above ambient conditions and contract as the weather fails. The same happens for the equipment connected with pipes. That extra growth needs to go somewhere.

The best way to address thermal stress is by adding flexibility to the piping system. It can be in different forms, including flexible supports, expansion loops/expansion joints and more. The secret key is to balance other solutions that deliver the elasticity you need.

Rigidity: Flexibility is not the only need for a piping system. Excess of it can make pipes exposed to environmental factors like wind and earthquake load. It also impacts transient forces like vibration, water & steam hammer. So it requires stiffness simultaneously.

Anchors are the primary way to make piping systems more rigid. They break the piping system into isolated pieces by preventing forces and movements from crossing them. The smaller sections in the system make it easier to troubleshoot when things go wrong.

To achieve the balance of pipe flexibility and rigidity, consider these basic system design rules:

*Limit pipe stresses within allowable code limits to prevent damage.

*Consider keeping forces pipe-equipment connections within limits decided by the equipment manufacturer.

*Keep large displacements from creating low spots in the pipe or causing the pipe to collide with nearby objects.

Piping Design Mistakes and Quick Fixes

Problems can arise due to a lack of careful analysis and design. Let’s have a look at some common mistakes in designing piping systems:

1. Pipe confined between rigid connections
If there are two pieces of equipment anchored to the floor and you’re running the length of pipe between them, then it’s going to heat up. The expansion has no way to go anywhere. So, either the pipe or equipment is going to give up depending on its strength. The way to lighten that stress is to avoid taking a straight route. Add expansion loops (U-shaped bends) to allow pipes to flex and grow to turn the stiff rod into a giant spring and relieve the stress.

2. Expand around the corner when using pipe guides
A series of guides often hold up long straight runs of piping supports made from pipe shoes. It allows pipes to grow by moving forward and backward without moving side to side. To enable that growth, consider cutting those clips off near the corners. It provides freedom to the pipe to move in both directions simultaneously.

Final words-
There are lots of challenges and pitfalls in designing a piping system. But the biggest one is not planning for action, making calculated decisions, or adequately protecting your network and equipment. Are you looking for detailed engineering services for your process industry? If yes, then consider hiring a reliable engineering partner.