Sealing
Typical expansion joints . The Chesterton 442C™ Cartridge Split Seal .
are often called ‘ polymers of low concern ’ and have a long history of safe use in diverse applications , from medical devices to aerospace and sealing devices . These polymers differ significantly from nonpolymeric PFAS materials .
What is a sealing device ?
Any device that prevents leaks from occurring in dynamic and static equipment components can be classified as a sealing device . Every pump , agitator , mixer , valve , or pipe run will have sealing to protect against :
• Aggressive chemicals
• Abrasive media
• Toxic or hazardous materials
• Gases / liquids / solids
• Harsh conditions
• Temperature extremes
• Full vacuum and extreme pressures
Sealing devices take many forms , from O-rings in mechanical seals to packing and gasket products to lip seals and expansion joints . Sealing devices are used in every industry , including :
• Power generation ( fossil , nuclear , renewable )
• Water / wastewater
• Oil & gas ( fugitive emissions )
• Chemical processing
• Mining / ore processing
• Pulp & paper
• Pharmaceutical
• Aerospace
• Semiconductor
• Military / defence
• HVACR
• Medical
• Any other industry with moving or stationary parts
There are two main channels for sealing devices : Original Equipment Manufacturers ( OEMs ) purchase them as a product component , and end users may replace them through aftermarket sources . As sealing devices are consumables , eventually , their performance will diminish and require replacement . When that happens , the end-users of the OEM products will either purchase new replacement products or procure replacement components ( sealing devices ), re-build the equipment during a maintenance cycle , and re-start the plant .
Why are fluoropolymers so important to sealing ?
Since the early 1950s , Fluoropolymers like PTFE have found extensive use in various applications due to their exceptional sealing properties . Their versatility , low friction , chemical resistance , and high-temperature stability make them an ideal choice for various industrial uses . Key properties of fluoropolymers include :
• Unmatched resistance to oxidation
• Imperviousness to most chemicals
• High-temperature stability
• Very low friction coefficient
• Excellent sealability
• Exceptional durability
• Long-lasting stability
• Resistance to degradation over time
Fluoropolymers are ideal for sealing devices , ensuring safety and effectiveness in various industrial applications . They offer durability and stability , reducing downtime . PTFE , for instance , minimises leakage , which is critical for sealing hazardous substances . Fluoropolymers are prevalent in the global sealing market , addressing high replacement costs , estimated at around 30 billion USD annually .
What do legislators think ?
Legislative efforts in the US and Europe aim to reduce and eliminate PFAS materials in manufacturing and products . However , most proposed legislation covers all PFAS forms rather than specifically targeting potentially harmful ones . While the intent is to address the risks posed by certain PFAS , regulating such a large group of chemicals is challenging . The one-size-fits-all approach needs revision since some PFAS are safe and essential for many applications . In the EU , there ’ s a proposal to ban all PFAS for a specified period , allowing industry input . In the US , federal and state levels are working on PFAS regulation , but definitions and intent vary . Discussions include a 1 part per trillion limit , but clarity is needed on testing frequency and measurement methods and accuracy . The lack of industrial standards and emotional-based regulations make distinguishing safe from unsafe materials difficult . This uniform approach will challenge various industries , including sealing applications , and make replacing proven and safe technologies difficult . For instance , compliance with strict VOC regulations would be unattainable without fluoropolymers in high temperature sealing devices . Mandating the removal of ALL PFAS materials will bring significant changes to numerous industries worldwide .
Is it easy to replace the fluoropolymers in sealing devices ?
The need for enhanced equipment uptime , reduced emissions , cost savings , and heightened safety is driving designers and manufacturers of sealing devices to develop more efficient and reliable products . With the increasing demand from new markets , it ’ s clear that fluoropolymers excel in their performance , with no known alternatives . For instance , the transition from LNG and LPG to hydrogen gas presents challenges due to the small size of hydrogen molecules , making sealing more difficult . Similarly , the unique nature of new biofuels requires the use of Fluoropolymers for effective sealing in emerging applications . The demand for superior sealing performance continues to rise , particularly in achieving zero ppm emissions in low-emission valve sealing within the petrochemical industry . Eliminating fluoropolymers like PTFE from existing sealing solutions would prevent them from meeting emission requirements .
30 Valve World June 2024 www . valve-world . net