Piping Technology and Products has a unique perspective on best practices in preventative maintenance. PT&P has a database built from over 1,000 audits performed in 41 countries. PT&P also has experience from over 3 Million pipe supports and expansion joints currently in service.
The design of the piping system is a major part of the engineering of an operating plant build. On average, piping constitutes 40-48% of the engineering hours in a new refinery. The challenge facing piping engineers is rotating equipment locations and process design are defined and the piping engineers must make the piping system fit within the designated space while dealing with thermal stress, proper flow, and allowable loads for all equipment. With temperatures in high energy lines often well over 1,000 degrees, this can be very challenging.
The following are some of the goals of pipe stress engineering and the placement of spring supports and expansion joints in the piping system: ensure stress at the interface to moving equipment is below maximum allowable loads, minimize turbulent flow through the piping system, and ensure the longevity of piping system components.
Operating plants tend to follow one of three strategies with their spring supports:
A. Only fix spring supports when something is wrong
B. Perform regular inspection and replace damaged spring supports
C. Periodically return piping line to its original design specification and/or set new design standard if the design has changed.
PT&P has seen many examples of each of the strategies above. Typically, the strategy taken at an individual plant is closely related to overall operating philosophy of the organization, including finance. However, we also speak to a number of organizations who have placed an emphasis on preventative maintenance but are not sure of the best practices for the engineered pipe supports and expansion joints.
For preventative maintenance, best practice is to not just focus on the health of the piping system components, but on the health of the overall piping system. The following are some of the issues that PT&P has found that cause system level issues:
By the time a plant reaches 10+ years of age, PT&P’s experience is that most plants have encountered one or more of the issues above. For this reason, it is essential to take an approach of resetting the line to the original design specification. Best practices for performing a “reset to design specification” are the following:
The challenge with this approach to preventative maintenance is that it takes a much deeper level of expertise than a component level inspection. PT&P’s experience is that even the ability to operate a pipe stress modeling software program such as CAESAR is far different than a pragmatic understanding of the proper functioning of all the elements of the piping line. Many personnel and firms supporting piping system maintenance are challenged with managing a broad range of equipment at an operating plant, and this can make it difficult to have the depth in pipe stress that may be required to properly execute a system level audit and execute a plant to return the piping system to the original design specification.
The sole purpose of performing audits is to maintain the piping system and equipment to remain in the proper condition. Therefore, the system level (pipe stress audit) that considers the physical condition of the system, along with the spring supports system should be preferred. As mentioned earlier, the component level audit is an important part of the system level which if put together with other system and/or deformation assessment can give the overall picture of the system and finally a better direction for the proper maintenance.
Media ContactCompany Name: Piping Technology & ProductsContact Person: Rosemary ReynoldsEmail: Send EmailPhone: 7134524846Address:P.O. Box 34506 City: HoustonState: TexasCountry: United StatesWebsite: www.pipingtech.com