Wear Rings Outperform Metals in Centrifugal Pump Parts
Vespel® wear rings, used in oil refineries, power and petrochemical plants, help increase reliability and lower costs.
DuPontTM Vespel® CR-6100 wear rings, throat bushings and line shaft bearings are durable, cost-efficient replacements for centrifugal pump parts made from metal or other composite materials.
Increased Wear Ring Life, Reduced Costs
Benefits of centrifugal pumps with Vespel® CR-6100 wear rings can include:
- Increased mechanical seal life and MTBR (mean time between repair).
- Reduced risk of seizure.
- Increased equipment and facility efficiency.
- Reduced repair costs.
Composite Versus Metal
Historically, wear rings have been made from metal, which can gall and seize the pump under contacting or run-dry conditions. This can result in abrupt, high-energy pump failure. With metal wear rings, design clearance is increased to prevent contact and seal failure, which has a negative effect on efficiency, suction condition, and overall pump vibration. With Vespel® CR-6100 wear rings, application designers have more flexibility when choosing to reduce clearances, without increasing the risk of seizure, thereby allowing for improved pump performance.
The Benefits of Reduced Clearance
When the risk of seizure is mitigated, wear ring clearance can often be reduced, as in the case of Vespel® CR-6100 centrifugal pump parts . Reductions in wear ring clearance increase the hydraulic radial force on the rotor. This additional hydraulic force will have the effect of reducing overall pump vibration, reducing shaft deflection, and increasing the pump life. These savings can lead to increased reliability, performance and higher productivity.
Vespel® Wear Ring Applications
Vespel® CR-6100 parts are used as the stationary wear rings in a wide range of centrifugal pump types. For pumps in nonabrasive services under 550°F (288°C), Vespel® parts have been applied with reduced wear ring clearance, resulting in improved reliability and performance. Vespel® CR-6100 has been applied to services prone to off-design operation, minimizing the risk of seizing failures associated with metal wear rings, and allowing the pump to continue in service after temporary run-dry conditions.
Vespel® Throat Bushing Applications
Installing Vespel® CR-6100 throat bushings instead of specially fabricated, spring-loaded, carbon bushings for close clearance applications, can be more cost effective, easier to install, and more durable than the specialty bushings.
Vespel® Line Shaft Bearing Applications
Vespel® CR-6100 parts are used for vertical pump line shaft bushings, instead of rubber, bronze, carbon, or other materials. For light hydrocarbons, condensate, or other services with limited lubricity, Vespel® parts help improve pump reliability.
For personnel who are repairing pumps, the installation of Vespel® CR-6100 parts reduces repair time. This increases equipment availability for service, and reduces the operational considerations of long-term equipment repair. Repair time is reduced, because parts can be produced and fitted quickly.
Vespel® CR-6100 parts have gained recognition under the ISO 13709 International Standard and the American Petroleum Institute’s API 610 Standard. The latest editions of both standards list Vespel® parts as a recommended non-metallic wear part for pump parts.
DUPONT PRODUCTS & SERVICES
Vespel® S products are highly durable polyimides used in demanding applications where exceptional thermal resistance (cryogenic to 349°C), low wear and/or low friction, strength and impact resistance are desired as custom parts or stock shapes.
Vespel® CR products provide excellent chemical resistance in refineries and chemical processing. They offer high-creep resistance and easy machinability for wear rings and tight-tolerance parts like ball-valve seats.
Vespel® ASB assemblies include fiber/fabric reinforced composites with metal backing that offer low wear & friction plus self lubrication, and metal-backed carbon-graphites for self-lubricating wear at extreme temperatures.
Vespel® TP thermoplastic family offers many products with excellent strength and toughness, dimensional stability, low outgassing, creep resistance, and low coefficient of thermal expansion for aircraft, automotive and industrial applications.
Vespel® SCP-5050 sweep-out fingers and stacker bar inserts for glass handling help increase plant reliability and efficiency and reduce operating costs at Veda-Pack glass manufacturing sites
The operator of a pipeline in the Southwestern U.S. was searching for a case ring material for pumps that would enable improved operating efficiency, increase equipment reliability and avoid the seizing or galling problems encountered with metal components. The metal components were replaced with Vespel® CR-6100 parts, and the results were impressive.
INFORMATION & IDEAS
Vespel® products are made from a variety of materials (polyimides, thermoplastics, composites and chemically-resistant polymers). These products offer a unique combination of physical properties and design flexibility. Parts are available as custom parts, stock shapes, components or assembles.