Victrex® Peek Film Chosen for Diaphragm Liner in Back Pressure Regulator
Greenville, SC (December 12, 2005) < When CIRCOR Instrumentation Technologies (CIT), a leading provider of fluid process instrumentation technology, encountered a sampling system application with ambient temperatures up to 260°C (500°F), it replaced the PTFE liner in a BP-3 series GO back pressure regulator with VICTREX® PEEK film because of its high temperature capabilities.
According to Scott Tomlinson, Sales Manager, North America and Product Manager for GO Regulator, "For many sampling system applications, PTFE works very well as a diaphragm liner. In fact, we¹ve used PTFE as our primary liner for over 30 years. Every once in a while, however, we run into an application where a little more chemical resistance and a little more temperature resistance are required. In this particular application, with maximum temperatures up to 260°C (500°F), the PTFE would migrate toward one of the internal ports of the back pressure regulator. When this happened, flow was restricted through the unit. VICTREX PEEK is a much more rigid material and doesn¹t have a tendency to cold-flow or creep like PTFE. It has not migrated toward the internal port and thus has provided an excellent solution for this application."
The liner is essentially a circular washer with a 1.725" O.D. and a .320 I.D. "We used 10 mil VICTREX PEEK film which works well inside the diaphragm assembly," says Tomlinson. "In this particular application, the media being used was a mixture of H2 and CO, and the working pressure wasaround 435 psi."
The VICTREX PEEK film is used as a barrier between sample process media and the backing of the diaphragm which in this particular application is stainless steel. "The diaphragm is a key wetted part inside the regulator that helps give us the ability to regulate pressure," explains Tomlinson. In this application, GO back pressure regulators are being used to maintain a constant pressure in an analyzer. "Applications for these types of pressure regulators can be very demanding, as these analyzers are typically used to validate samples of process media that are being produced in refineries, chemical plants, and a variety of other petrochemical/natural gas processing facilities," adds Tomlinson. In addition to excellent high temperature creep resistance required for this application, PEEK has high purity and is an excellent moisture and gas permeation barrier.
CIRCOR Instrumentation Technologies is a product group within CIRCOR International. A leading global provider of fluid process instrumentation technology, CIT services customers in the food and beverage, chemical, petrochemical, refinery, oil and gas, electric and gas utilities, industrial and instrumentation markets.
VICTREX USA Inc., a division of Victrex plc., is the sole manufacturer and supplier of PEEK polymer worldwide. For more information on the properties and performance advantages of VICTREX PEEK, please call (800) VICTREX or visit the Victrex website at www.victrex.com.
