Critical seals and gaskets: asking the right questions

Sometimes they may look pretty familiar and insignificant, but seals and gaskets are rapidly advancing fields of technology that perform functions vital to safety, testing, manufacturing, mining, energy, and liquid and gas reticulation operations.

They play a key role in ensuring the efficacy and longevity of valves, pumps, reticulation systems, machinery and automation solutions, where they are essential in avoiding leaks of fuel, fluid power mediums, harmful emissions, vapours and chemical and aggressive process solutions. But because they may look so simple and familiar, users may assume that what has done a job previously will continue be sufficient to meet a whole host of issues that may arise in the future, including new challenges where they are essential to the integrity of process automation, materials handling, machine construction and maintenance and safety, hygiene and export compliance.

Sometimes this approach may be right. Proven can be good, if the application is the same, or very similar. But trusting old solutions with new tasks may also be wrong. New machinery technologies (faster, higher pressure, more automated) may demand new seal and gasket capabilities, and seal and gasket material capabilities may themselves have advanced considerably since material selection was last addressed.

“With advancing material innovation there may already be a better solution that will give a better and safer sealing performance for a considerably longer time,” said seal and gasket engineering specialist Vinh Lam, General Manager of CSGtech. “Familiarity may have lulled the specifier into missing out on increased efficiencies, reliabilities, service life and avoidance of downtime that newer seal and gasket technologies can provide.

“Certainly the developer of a new machine or process cannot afford to go down an old path until it comes to a dead end in terms of performance required,” he added. And with fault troubleshooting and reliability issues, companies need to focus very carefully, because there is great upside in getting the choice right for optimum reliability, cost efficiency and speed of a new and improved product to market.

“Conversely, there is potentially a high price for failure in terms of spills, leaks, product and safety hazards and reputational damage if the job is not done right the first time.”

Material selection isn’t always just a simple matter of reading a compatibility chart or accepting a component manufacturer’s headline statement, such as ‘food-compatible’ or ‘purpose-compatible’ at face value. Sometimes such statements are perfectly true in relation to one particular part of a range, but may not be intended to apply to the entire range.

Ask the right questions

“Obviously, the best approach is proactive rather than reactive,” Lam said. “We suggest you pose yourself some simple questions so you can clearly brief suppliers in this specialist field, instead of moving down a path of old solutions to new problems, or a series of dead-end trials or less-than-optimum solutions. Seal and gasket technology is a fast-moving field and even the best professionals just may not have the time to know it all.

“There are a lot of good and bad options out there, especially when working with composites and raw materials, where capabilities and performance continue to advance.”

Preliminary questions to be addressed in briefing a seal or gasket supplier include:

• What range of applications are we looking at?
• What range of materials do we need to seal?
• What are the operating conditions, including temperatures, chemicals and pressure loads?
• What are the particular traceability, compliance and standards criteria you must meet or exceed?
• What do you like or not like about what is currently being used or proposed?
• What are the seal or flange conditions? Is there sufficient load capacity and space available?
• What is the design life of the joint?
• What is the target price range? Are we basing on price or performance?
   

“The more detailed answers you can give the seals and gasket specialist you are briefing, the easier and quicker it will be to take a look at your needs and establish the best and most cost-efficient design solution to meet them,” Lam said. “The answer may involve a tailored solution or even technology that already exists, but that some fields of industry are not familiar with.”