Few components have more influence on the performance of a valve than the seal. Its job is to guard against leakage resulting from wear and tolerance variations in the valve hardware.
The choice of polymer seal material for Industrial Valves（Ball valve, safety valve etc.） is vital to its performance.Here are the most commonly used options for polymer seals in valves.
• Virgin PTFE
Virgin PTFE is an ideal seal material for pressures less than 5 ksi and temperatures between -5℃ and 200℃; PTFE with good chemical resistanc and extremely low friction. However, its temperature performance does depend on pressure. PTFE does not decompress well after being pressurized.
• Glass Reinforced PTFE
Reinforced PTFE (commonly use15% glass fiber), increasing the temperature and pressure rating.
Compared with virgin PTFE，glass reinforced PTFE still has very good chemical resistance.
• Carbon fiber PTFE
PTFE filled with carbon fiber,it increases compressive strength, hardness, wear, and load properties，reduces creep and cold flow.
PCTFE is a kind of perfect sealing material under cryogenic and high pressure conditions.It has excellent rigidity, low temperature resistance, cryogenic fluid resistance and good size stability.
Modified PTFE has some new or improved characteristics over virgin PTFE: Increased stiffness & improved creep resistance;Part surfaces are smoother and less porous - components stay clean since they are less likely to trap contaminants;Low micro-void content yields improved permeation resistance;Longer flex life than PTFE
PEEK works well with wide temperatures, and is unaffected by continuous exposure to steam and hot water. It is tougher than PTFE, but also harder. Its major shortpoints, besides its rigidity, is its brittle behavior at lower temperatures.
Tags: polymer seal material