Our Guide to Selecting the Appropriate Valve Packing Material
Everybody knows how important it is to choose the right packing material – even that one particularly clueless apprentice who didn’t seem to know his left from his right. The material you select for valve packing influences the strength, flexibility and resilience, which all play a role in the effectiveness of their sealing. Choosing the wrong packing material for the wrong task could result in improper sealing, which is definitely not ideal. Let’s go through some of the packing material basics, as a guide to selecting the right valve packing material.
PTFE
PTFE is one of the most widely used materials for valve packing. PTFE has a wide range of chemical resistance and can be used in applications which are incompatible with elastomers. It’s thermally stable across the temperature spectrum and has a service range of -70 °C to 200 °C. PTFE can temporarily withstand temperatures of -240 °C and has been successfully used in cryogenic applications.
Graphite
Graphite is another valve packing material which is excellent for certain purposes. Graphite is a flexible graphite made from pure, natural graphite flake. It’s resistant to heat, fire, corrosion and certain aggressive chemicals. Graphite packing is chemically resistant to nearly all organic and inorganic fluids, except for highly oxidizing acids and chemicals. This effective resistance to compromising chemicals can be seen across Graphite’s entire temperature range of -240 °C to 450 °C. It’s especially appropriate for centrifugal pumps and it fits for all fluids apart from strong oxidants.
Polyester
Polyester valve packing material is made from synthetic fibre yarn and is a great option as a universally applicable product. It’s designed by impregnating it with PTFE on the wire, during the braiding and on the body. It’s ideal for packing for general uses in centrifugal and alternative pumps, valves, agitators and mixers.
Incorbraid
Incorbraid is a special packing in pure graphite yarn but with discontinued micrometallic reinforcement. It’s impregnated in three phases: on the single yarns, on the body and on the surface of the yarn. Incorbraid is especially good at valve packing where resistance to temperature and long-life use is required. This makes it ideal for packing the H.P and H.T valves at power and petrochemical plants.
Don’t choose your valve packing material on a whim; come see the experts at Steamline Engineering. They stock a range of quality packing materials and can assist you in making the right choice in material selection. Steamline Engineering are Australia’s industrial experts, with plenty of other products including pump packing, gasket material, sealing sets, thermal insulators and more. For a top quality product, guaranteeing efficiency and long life, get in touch with the specialists at Steamline Engineering – grab a quote today.