When fluids stop moving through pumps, an upset condition called dry run occurs, resulting in higher operating temperatures and increased wear and vibration. This could happen during startup, when a pump's bearings and wear rings may have insufficient process media for lubrication. The result is a dry running scenario during which the mating surfaces will wear. A short-term dry run condition may not be a problem, but a dry run of a longer duration could lead to complete pump failure.
Regardless of the time frame under which dry run occurs, this upset condition can result in costly repairs and a reduced MTBR/MTBF (mean time between repair/mean time between failure). One solution would be to use a material that offers superior wear and dry-run capabilities, increases MTBR/MTBF, and improves rotating equipment reliability and efficiency, thereby resulting in cost savings.
Greene Tweed’s WR® 650 PFA composite is that solution. Its unique, 3D braided, carbon fiber structure wrapped in a PFA matrix offers superior wear and dry-run capabilities that are particularly beneficial for stationary wear parts in centrifugal pumps (e.g., vertical, horizontal, single, and multi-stage pumps) used in refinery, chemical, water treatment, and power plants.
WR® 650’s differentiator is its unique, 3D braided, carbon fiber structure wrapped in a PFA matrix that provides great non-gall and non-seize properties. Acting as a sacrificial component, the self-lubricating nature of PFA ensures metallic counter parts are preserved, even those that are relatively soft.
WR® 650 also exhibits radial CTE (coefficient of thermal expansion) comparable to steel, and operability from cryogenic to 500°F (260°C) applications. Tribological test results (plain bearing on shaft method) conclude the PV limit for WR® 650 exceeds other competitive PFA-based materials by 2.5 times before exhibiting signs of degradation.
WR® 650 is also an excellent material choice for chemically harsh environments. It’s almost universally chemically resistant to withstand applications where PEEK-based products are insufficient.
WR® 650 is available as custom machined-finished parts as requested, stock shapes from 2- to 12-inch OD, and a standard 6-inch length (larger sizes are possible).
Greene Tweed also offers the broadest range of high-performance thermoplastic composite materials (ideal for wear rings, bearings, bushings, etc.) including WR® 300, WR® 525, WR® 575 and WR® 600 for normal- to-high wear-resistant applications, and AR®-1 and AR®-HT for abrasion-resistant applications.
Greene Tweed products are sold and distributed worldwide. Click here (https://www.gtweed.com/contact-us/) to contact Greene Tweed regarding our composite material solutions.