Vespel® CR-6100

Vespel® CR family provides excellent chemical resistance in refineries or chemical processing. They offer high-creep resistance for seals, run-dry capability for wear rings for pumps and easy machinability for tight-tolerance parts like ball-valve seats.

The CR-6100 grade of DuPont™ Vespel® parts and shapes is a composite material consisting of carbon fibers held in a Teflon® fluorocarbon resin matrix. Vespel® CR-6100 has been installed in thousands of pumps in refineries, chemical plants, power plants, and other fluid processing facilities since 1996. It has replaced metal and other composite materials used for pump wear rings, throat bushings, and line shaft bearings to help users increase pump reliability and performance. The properties of Vespel® CR-6100 help to reduce the risk of pump seizure and allow internal rotating-to-stationary part clearances to be reduced by 50% or more.

Applications

A large hydrocarbon processing facility in Central Alberta was using a nine-stage horizontally split-between-bearings pump (right photo) with 12-chrome stationary and rotating wear components to feed water to a boiler.
DuPont™ Vespel® CR-6100 is used for I.D.-mounted (in compression) wear components in nearly all centrifugal pump types in non-abrasive process services up to 500 °F (260 °C).
Pump Components • Wear rings • Line shaft bearings • Inter-stage bearings• Throat bushings• Pressure-reduced bushings
Pump Services Vespel® CR-6100 has been used in thousands of pumps in a broad range of hydrocarbon, chemical and water services. Some applications include: • Boiler feed • Condensate • Propane • Butane • Ethylene • LPG • Diesel • Gas oil • Sour water• Naphtha• Gasoline• MEA• DEA• Sulfuric acid• Ammonia• Hydrofluoric acid• Caustic• Lube oil
Pump Types • Overhung horizontal • Between bearings• Vertical• Multistage
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 pumps were nine-stage horizontally split units made by Sulzer Bingham. The process fluid consisted of natural gas liquids (NGL) at ambient temperature.

Special Warnings

Electric motor standards include external sealing but not effective inner cap sealing. All motors constructed to the latest IEEE and API standards should have a “close” running inner cap (Diametric clearance of 0.015” to 0.040”). This still allows for limited lubricant ingress to the windings. Lubricant entering the stator is a problem for many plants because it degrades insulation and interferes with cooling which causes premature motor failure. These problems lead to low reliability and increased maintenance costs.
Extended stationary or standby periods can cause corrosion of metallic wear components by sea water. Short periods of run-dry as the pump starts can provoke seizures. These issues decrease reliability of the pumps and increase repair and preventive maintenance costs.
Many electric motors have rolling element bearings that need to be lubricated while protecting the armature and stator from the intrusion of lubricant and subsequent damage. Typical lubrication is based in the application of oil or grease. Antifriction bearings are typically lubricated by one of three methods: grease lubrication, oil mist lubrication, and oil sump lubrication.
Metallic wear components usually found on critical rotating equipment can contact when pumps run dry leading to frequent seizures and costly repairs which reduces plant uptime. Although some nonmetallics are used to reduce run dry situations, many have chemical compatibility issues with some services including Amines.
Process upsets. Survival of case rings under run-dry conditions caused by process upsets is highly desirable.
Sleeve bearings support series of 21 foot (6.4m) long shafts in the 4 inch (101.6mm) diameter range. Unit size determines the number of shafts and some units are hundreds of feet long. The bearings drive skimmers and are historically babbitt or bronze. Greased bushings fail due to corrosion and contamination. Nickle-graphite bushings wear and score the shafts..
The facility’s engineers wanted to find a way to eliminate running a second pump because it greatly increased operating cost, and they needed to avoid a recurrence of seizure incidents previously encountered with the primary pump
Tighter clearance. Reducing clearance between the case ring and the hard metal surface of the impeller is a proven method of increasing pump efficiency, but it would increase the frequency of contact between the case ring and impeller.

Solutions

Can operate without lubrication because of its low wear and low coefficient friction.
Can operate without lubrication because of its low wear and low coefficient friction.
Can operate without lubrication because of its low wear and low coefficient friction.
Reduce the leakage of oil mist into the stator.
Solve the problem of lubricant and contamination entering the motor’s windings, as well as support the armature in the case of a sudden bearing failure.
Stationary wear components in the primary pump.
Wear rings along with center, throat and throttle bushings in one of its pumps.
Wear rings along with center, throat and throttle bushings in one of its pumps.

Features & benefits

	Because total water flow in the main CWT increased by more than needed to compensate for the decommissioning of the smaller CWT unit, additional savings in energy (in electricity and steam) of over $200,000 per year were achieved. The full decommissioning of the smaller CWT led to savings in electricity and maintenance that were estimated to be over $400,000 per year (at $0.06 per kWh). The cost to overhaul five pumps and one spare pump has been fully paid with the energy savings of just one year. If avoidance of yearly maintenance costs of the smaller CWT unit were included, the savings figures would be even larger. With smaller clearances made possible by Vespel® CR-6100, water recirculation and turbulence has been reduced, increasing flow and discharge pressure. The combined result of pump overhaul resulted in an improvement in pump efficiency of about 8%.
Higher efficiency	The operator measured a 3% gain in pump efficiency over the pump manufacturer’s performance test curve.
No seizures, no repair costs to date.	As of January 2011, the pump has operated for three and a half years without a single seizure failure. That has saved $65,000 in annual repair costs that would have been needed with metal wear components, adding up to nearly $200,000 in three years
Extending the benefits	Based on the proven 3% efficiency gain and run-dry capability of Vespel® CR-6100 parts in this particular situation, the operating company installed CR-6100 parts in the pipeline’s eight additional pumps
Long life	The pump continued in operation for the next six months, completing its planned production cycle. During this time, there was no noticeable change in pump vibration or efficiency. At the end of the cycle, the pump was disassembled to inspect the rotor (see photo). The Vespel® CR-6100 parts had survived the incident with no measurable wear, and there was no damage to the pump rotor
Increased safety	The operator reported that the continued operation of Vespel® CR-6100 parts during the process upset helped significantly in avoiding a release of hazardous material.
Run-dry survival	Shortly after installation of the Vespel® CR-6100 parts, a control problem caused the pump to run “blocked-in” with both suction and discharge valves closed for 38 minutes. After the pump was shut down and cooled, operators were surprised that the rotor still turned freely. They then replaced mechanical seals, checked alignment, and returned the pump to normal operation.
Vespel® CR-6100 offers improved performance versus other wear ring materials	Vespel® CR-6100 is based on a fluoropolymer, which gives it broad chemical resistance and a low coefficient of friction. These characteristics coupled with its high temperature resistance and low thermal growth make Vespel® CR-6100 a suitable candidate for a wide range of applications. • The durability of Vespel® CR-6100 aids installation and machining, and stays tough during operation.
Reduced vibration	With Vespel® CR-6100 parts, the pump runs with much less vibration than previously
Pump performance and reliability are significantly improved.	• Because Vespel® CR-6100 is non-metallic, has a low coefficient of friction, and excellent dimensional stability, it can withstand short-duration off-design conditions such as start-up, slowrolling, low-flow, cavitation, or run-dry situations. The pump remains available for service, resulting in potentially lower repair costs. • With these characteristics, clearance at wear components can be reduced. This results in efficiency gains which lead to significant operating cost reductions, particularly when applied to populations of pumps. • Improved reliability: Pumps with reduced clearance also exhibit lower vibration levels and reduced cavitation. Seals and bearings last longer, and MTBR increases.
Sharply lower operating cost and increased efficiency	Increased efficiency achieved with the clearance reduction enabled by Vespel® CR-6100 parts made it possible to operate at full capacity with a single pump instead of two. The elimination of the second pump saved $100,000 per year in operating cost. In addition, the pump now draws 5% less amperage, saving $6200 annually based on a typical North American power cost of $0.06/kWh.

Available Sizes

Gross Weight	Net Weight	Carton Each	Carton Length	Carton Weight	Carton Height
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Other Property

Property	Value	Unit	Method
Water Absorption, 24 hr	ASTM D-570	% by weight	0.01
Interlaminar Shear Strength	Internal Test	MPa (ksi)	17 (2.4)
Specific Gravity	ASTM D-792	—	2.06
Hardness	ASTM D-2240	Shore D	82 84

Thermal Property

Property	Value	Unit	Method
CTE, Linear	ASTM E-831	10-6 m/m·°C (10-6 in/in·°F)	5.6 (3.1) 300 (170) 470 (260) 750 (420)
Thermal Conductivity	Hot Wire Method	W/m-K (BTU-in/hr-ft²-°F)	0.7 (4.7)
Heat Deflection Temperature at 264 psi	ASTM D-648	°C (°F)	315 (600) 120 (250

Wear Property

Property	Value	Unit	Method
PV Limit	Internal Test Falex	MPa.m/s (psi.ft/min.)	9.7 (278,000)

Mechanical Property

Property	Value	Unit	Method
Tensile Modulus	ASTM D-3039	MPa (ksi)	2,800 (405) 330 (47.4)
Compressive Strength	ASTM D-695	MPa (ksi)	18 (2.6)
Un-Notched Izod Impact	ASTM D-256	J/m (ft-lb/inch)
Tensile Elongation	ASTM D-3039	%	1.2 1.6
Notched Izod Impact	ASTM D-256	J/m (ft-lb/inch)
Compressive Modulus	ASTM D-695	MPa (ksi)	1,730 (250)
Flexural Modulus	ASTM D-790	MPa (ksi)	3,720 (540)
Flexural Strength	ASTM D-790	MPa (ksi)	43 (6.3)
Tensile Strength	ASTM D-3039	MPa (ksi)	52 (7.6) 2.8 (0.4)

Product Details

Fabric/material	CR-6100 PARTS
Design	CR TUBE
Seam	PFA
Packaging	BLANK
Hazard
Coated Material	TEFLON PFA
Features	CR-COMP. MOLDED MACHINED SHAPE

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