PTFE may sound like a cheap and cheerful material for valves, but care and attention is required to prevent surface damage.
“Every day is a learning opportunity”, is a saying which is often heard here in the Valve World editorial department. After all, the valve industry is so diverse, and the number of applications so huge, that no-one (and certainly not a humble editor!) can possibly hope to know everything.
I recently had my own deficiencies pointed out to me when visiting ABO valve in the Czech Republic. I had just interviewed the commercial director Mr Miro Student about what makes the valve industry in the Czech Republic so strong when he offered to give me a guided tour of his facilities. Having gone through the engineering office, the machining areas and the assembly stations, he opened a locked door and pointed out several work benches where lined valves were in various stages of assembly.
My immediate thought was: “strange, surely there was space enough for these benches in the main assembly area?” In fact, I voiced this thought to Mr Student, who kindly but firmly put me to rights. “Well, these valves are lined with PTFE. Now you probably know about PTFE from its use in frying pans at home. It’s a superb non-stick material, and you can put the frying pan into the dishwasher without any problem,” he commented. “In the chemical industry PTFE has equally proven its worth when corrosion resistance is needed in pipes and valves. However, what many people don’t realise is that the PTFE surface can be all too easily scratched by particles in the air. That’s not a concern for your frying pan, but such scratches can cause valves to leak. This is why we, like other manufacturers, assemble PTFE lined valves in what are basically clean room style facilities. In addition, PTFE lined valves have to be handled with care not only during production but also special attention must be given to packaging as during transportation damage can occur as well.”
Point taken. In fact, when back in the office I looked up a number of companies offering PTFE-lined valves and saw that one manufacturer was located in Switzerland. In other words: if it is economical to manufacture valves in a country where labour is expensive, then they must be high-end products indeed.
TFE lined valves require due care and attention during
assembly and transport to prevent surface damage to the PTF
And just a few days after visiting ABO I met up with an end user who –almost in passing – started to discuss the use of PTFE lined valves in a pharmaceuticals facility. He too said it was important to take surface damage into account in order to keep the valves in good working order.
So that was my latest “learning moment” but as always I’d be interested in getting yet more thoughts and impressions about how and where PTFE is used in valves. So if you have any insights, information or tips to share, I’d be sincerely pleased to hear from you.
Best regards,
David Sear.
About the author
David Sear is Online Editor. He is contributing to articles, interviews and reports to KCI’s magazines and websites. David also works on videos for KCI Television.