Case Rings and Wear Rings
Pump wear rings and case rings made from GRAPHALLOY® materials can significantly improve the reliability and efficiency of both horizontal and vertical pumps. The unique properties of the Graphalloy material, a range of self-lubricating graphite-metal alloys, benefit users across a wide variety of pump services.
Read more here.
GRAPHALLOY 'Disaster' Bushings for Improved Safety in Case of Seal Failure
“Disaster Bushings” are used in pumps outside the seal to minimize product leakage to the environment in the event of a seal failure. GRAPHALLOY® materials provide ideal properties for a disaster bushing.
GRAPHALLOY Bushings and Bearings
Showing posts with label pump. Show all posts
Showing posts with label pump. Show all posts
Friday, November 8, 2019
Thursday, August 30, 2018
GRAPHALLOY® at Turbomachinery & Pump Symposia 2018
Graphite Metallizing Corporation will be exhibiting at the 2018 Turbomachinery & Pump Symposia. This conference is being held at the George R. Brown Convention Center in Houston, TX from September 18-20.
Please visit us in Booth 1216.
To learn more about this conference, click here.
Thursday, December 11, 2014
Solving Subpar Pump Performance by Finding the Right Material
A petrochemical manufacturing plant recently faced material-related
issues with two fractionator pumps at its performance products plant in
Texas. Pump performance was gradually falling off to a point where the
pump could not keep up with demand.
By Eric Ford, Vice President, Graphite Metallizing Corporation
Pump Engineer, November 2014
A petrochemical manufacturing plant in Texas was experiencing frequent pump failures, as often as once every year, on their Worthington model 3UNX-105
multistage pumps. The pumps were being used to transfer Tert-Butyl alcohol at a temperature of 110°F, suction pressure of 10 psi, and a discharge pressure of 500 psi. The fractionator had an operating pump, an installed spare pump, and spare rotors in a warehouse as backups. A spare rotor would be installed into the failed pump, while the damaged rotor was pulled from service and sent for repairs.
The Area Maintenance Engineer started looking for a longer-lasting option to reduce costs. While the pump was originally supplied with stainless steel bushings and impeller wear rings, these were subject to galling on start-up, and during upset conditions. An upgrade to PEEK material resolved the galling issue, but over time the resin binder started to break down allowing critical clearances to increase and pump performance to drop off. The repair shop suggested switching to a higher,more expensive grade of PEEK.
This idea was rejected as there was no guarantee that the new PEEK material would hold up any better as it had not been tested or used in this service before. After more research, the decision was made to replace the bushings and wear rings with nickel-filled GRAPHALLOY® graphite/metal alloy components, which allow the graphite layers to slide against each other resulting in excellent dry lubrication, is stable chemically, unaffected by ordinary solvents, and can withstand high temperatures without deformation or burning.
The pump internals are 300 series stainless steel. The supplier provided wear rings that were finish machined and installed into the pump’s 300 series stainless steel housings. The new material was installed into the eye and hub-side stationary rings, as well as the throat, throttle and center bushings. The first GRAPHALLOY-fitted spare rotor was installed into the pump. The damaged rotor with the PEEK bushings was sent to the shop and fitted with new graphite-based components.
The pump has been through several start/stop cycles and over a year in continuous service without any indication of increasing wear ring clearance or degradation. It has exceeded the runtimes of the previous bushings
Click here to learn more about GRAPHALLOY.
By Eric Ford, Vice President, Graphite Metallizing Corporation
Pump Engineer, November 2014
The Area Maintenance Engineer started looking for a longer-lasting option to reduce costs. While the pump was originally supplied with stainless steel bushings and impeller wear rings, these were subject to galling on start-up, and during upset conditions. An upgrade to PEEK material resolved the galling issue, but over time the resin binder started to break down allowing critical clearances to increase and pump performance to drop off. The repair shop suggested switching to a higher,more expensive grade of PEEK.
This idea was rejected as there was no guarantee that the new PEEK material would hold up any better as it had not been tested or used in this service before. After more research, the decision was made to replace the bushings and wear rings with nickel-filled GRAPHALLOY® graphite/metal alloy components, which allow the graphite layers to slide against each other resulting in excellent dry lubrication, is stable chemically, unaffected by ordinary solvents, and can withstand high temperatures without deformation or burning.
The pump internals are 300 series stainless steel. The supplier provided wear rings that were finish machined and installed into the pump’s 300 series stainless steel housings. The new material was installed into the eye and hub-side stationary rings, as well as the throat, throttle and center bushings. The first GRAPHALLOY-fitted spare rotor was installed into the pump. The damaged rotor with the PEEK bushings was sent to the shop and fitted with new graphite-based components.
The pump has been through several start/stop cycles and over a year in continuous service without any indication of increasing wear ring clearance or degradation. It has exceeded the runtimes of the previous bushings
Click here to learn more about GRAPHALLOY.
Wednesday, August 6, 2014
Success in Refinery Boiler Feedwater Pumps
GRAPHALLOY® has many years of success in boiler feedwater pump applications. The non-galling, self-lubricating features of GRAPHALLOY allows pumps to continue working even when they encounter a run dry situation.
A Texas refinery has four Ingersoll Rand 6-stage CNTA radial split horizontal pumps in their boiler section. The operating units that use this boiler section have a lot of steam turbine driven equipment.
Demand Changes Can Cause Seizing
Problems occur when the amount of steam needed changes and the rate is quickly increased or decreased. The demand on the steam turbines causes the boiler feed pumps to operate anywhere from shutoff to maximum flow. As the demand for steam increases or decreases, a signal is sent to one of the stand-by pumps to start up or, for an operating pump, to shut down. When this happens, it sometimes starves the operating pump, causing it to momentarily run dry.
When a pump runs dry, metal to metal contact occurs between the rotating and stationary wear surfaces. The wear rings can weld to the shaft, damaging both the rings and shaft. In some cases, the entire pump needs to be overhauled at a substantial cost. Until the failed pump is replaced by a spare, the capacity of the operating unit is reduced, potentially resulting in lost revenues.
The GRAPHALLOY Solution
The refinery installed nickel-grade GRAPHALLOY stationary Wear Rings, Throat Bushings, Throttle Bushings, Channel Ring Bushings and Crossover Center-Stage Bushings in one pump. The second pump was converted to GRAPHALLOY a month later. Both converted pumps survived an ensuing dry run that caused the third, metal-fitted, pump to fail. The third and fourth pumps were then converted to GRAPHALLOY.
Results
The non-galling characteristics of GRAPHALLOY allow the pumps to operate safely at unstable flow rates. After the first year of service following the GRAPHALLOY upgrade, the pumps were operating above the performance curve in both capacity and developed head. In addition, vibration levels were well below the alarm set level.
For more information about GRAPHALLOY, click here.
A Texas refinery has four Ingersoll Rand 6-stage CNTA radial split horizontal pumps in their boiler section. The operating units that use this boiler section have a lot of steam turbine driven equipment.
Demand Changes Can Cause Seizing
Problems occur when the amount of steam needed changes and the rate is quickly increased or decreased. The demand on the steam turbines causes the boiler feed pumps to operate anywhere from shutoff to maximum flow. As the demand for steam increases or decreases, a signal is sent to one of the stand-by pumps to start up or, for an operating pump, to shut down. When this happens, it sometimes starves the operating pump, causing it to momentarily run dry.
When a pump runs dry, metal to metal contact occurs between the rotating and stationary wear surfaces. The wear rings can weld to the shaft, damaging both the rings and shaft. In some cases, the entire pump needs to be overhauled at a substantial cost. Until the failed pump is replaced by a spare, the capacity of the operating unit is reduced, potentially resulting in lost revenues.
The GRAPHALLOY Solution
The refinery installed nickel-grade GRAPHALLOY stationary Wear Rings, Throat Bushings, Throttle Bushings, Channel Ring Bushings and Crossover Center-Stage Bushings in one pump. The second pump was converted to GRAPHALLOY a month later. Both converted pumps survived an ensuing dry run that caused the third, metal-fitted, pump to fail. The third and fourth pumps were then converted to GRAPHALLOY.
Results
The non-galling characteristics of GRAPHALLOY allow the pumps to operate safely at unstable flow rates. After the first year of service following the GRAPHALLOY upgrade, the pumps were operating above the performance curve in both capacity and developed head. In addition, vibration levels were well below the alarm set level.
For more information about GRAPHALLOY, click here.
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