Inadequate storage and the mishandling of gaskets, as well as inaccurate gasket material selection for an application – often treated as trivial or an afterthought – can be critical in precluding monetary losses and even dangerous occurrences, says industrial gaskets and sealing material manufacturer Absolut Gaskets MD Mark Stöger.
Gaskets are available in a diverse range of complex materials and not choosing the correct gasket for an application occurs often. This can result in gasket failure, which, in turn, often leads to significant, but unnecessary costs, as well as frustration, as an operation will have to be shut down to replace the gasket.
“Gaskets are most critical in piping systems. Deterioration and damage needs to be minimised to avoid leakage,” he adds.
By knowing the temperature and pressure of the medium being pumped through a piping system, a process of elimination can be applied to select the appropriate gasket material and grade to be used in that application.
Stöger says gasket materials are also often kept in storage for a long period before being used and storage practices are generally not controlled well enough. Different gasket materials require different storage environments.
The environment to which a gasket is exposed during manufacturing, distribution and storage affects the gaskets integrity and composition. A gasket’s shelf life is defined as from when the gasket material is manufactured to the point that its quality or performance becomes unacceptable.
Therefore, “optimum storage can significantly influence the gasket’s shelf life”, says Stöger, both in the raw material form as well as the finished manufactured gaskets.
For example, elastomer-bonded fibre gaskets, providing a reliable service for many bolted flange connections, are not designed to be stored for extended periods and are often considered to be practically unaffected by storage, if stored correctly.
However, with modern, person-made reinforced fibres this is simply no longer true – as elastomer-bonded fibre ages, it involves irreversible chemical processes. Ideally, elastomer-bonded fibre gaskets should be stored between 4 °C and 27 °C, with 40% to 70% relative humidity, in a room with no windows and non-ultraviolet (non-UV) or low-UV producing light, minimal dust and no chemical storage nearby, says Stöger.
On the other hand, with gaskets made of multi-layered nuclear grade graphite - a top-of-the-range material that is used in high-temperature, high-pressure applications - the usual elements such as sunlight, heat and humidity, which degrade materials like elastomer-bonded fibre, are neutralised.
“In power generation, graphite is a medium that is often used in super-heated steam applications,” Stöger tells Engineering News.
Multi layered graphite is particularly brittle and expensive.
Absolut Gaskets uses atom semi-robotic machines to cut multi-layered graphite sheets, and takes specific care when handling it, keeping it flat and elevated off the ground in storage, thus ensuring no damage.
“If graphite is dropped, we lose a lot of money; and if there is a scratch and it is installed in a high-pressured steam environment, there’s a major safety issue,” says Stöger.
Further, sanitation is critical when manufacturing and handling gaskets for industries that produce products for human consumption such as food and pharmaceuticals. Absolut Gaskets supplies polytetrafluoroethylene (PTFE) gaskets to the food and pharmaceuticals industry. These materials require Food and Drug Administration (FDA) approval.
To acquire approval from the FDA to export PTFE gaskets, suppliers such as Absolut Gaskets need to keep the PTFE material spotless and free from oils, dust and chemicals that can remain on the gasket from storage and contaminate medication and food products.
”To avoid contamination from occurring, we cut the PTFE only on one semi-robotic machine, no other types of materials are cut on that machine. The gasket is then subjected to a whole cleaning process and quality assurance, after which it is placed into a vacuum-sealed bag and carefully marked accordingly,” declares Stöger.
Absolut Gaskets also sells PTFE for oxygen application products, and the cleaning process for these applications is just as essential. If there is oil or dust on the gasket, and it is exposed to pure oxygen, it can cause an explosion at the plant.
Stöger concludes that avoiding reckless methods of transportation should also be a priority to gasket distributors to preserve the materials’ integrity.