GRAPHALLOY Bushings and Bearings

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Wednesday, May 25, 2011

GRAPHALLOY® Takes a Stand Against Heat and Sand

A foundry that specialized in ferrous and non-ferrous shell molded castings had a bearing problem. The high heat and sand in their molding machines were destroying their brass bushings and stopping their production. GRAPHALLOY®, manufactured by Graphite Metallizing Corp.,provided a solution for this difficult problem.

During production, a casting pattern was mounted to the bottom plate of the machine. Sand was added to the plate. The plate was then rolled back to the center position and the oven lowered over the mold to bake the pattern. The bushings in the arms lowering the oven were exposed to 500°F degrees as well as grit and sand.

As a result of these harsh operating conditions, the brass bushings lowering the oven over the mold were only lasting 2 - 4 weeks. Replacing these bushings required two men - working for nearly two  hours - to make the repair.

The local Graphite Metallizing engineering representative was contacted. A recommendation was made to replace the brass bushings in the arms that raise and lower the oven with GRAPHALLOY Grade 212 High Temperature Bushings.

After the GRAPHALLOY bushings had been in use for 14 months, there was only .003 wear. The company was so pleased with the performance of the GRAPHALLOY bushings that additional orders were placed for all 13 of their molding machines. One of the maintenance repairmen estimated that he was personally saving 30 hours a month.

Once again, GRAPHALLOY proved to be the answer for difficult, high temperature applications.

Thursday, April 28, 2011

GRAPHALLOY® Bearings for High Temperature, Environmentally Sensitive Designs

Graphite Metallizing Corporation is pleased to announce a family of Tin Based Babbitt GRAPHALLOY® materials for high temperature bearing applications up to 350° F (175° C). These tin based babbitt materials are available in NSF® certified grades for drinking water and are FDA accepted. They will perform reliably as self-lubricating bearings in submerged and dry applications.


GRAPHALLOY (a graphite/metal alloy) Tin Based Babbitt offers many advantages. It is environmentally safe to machine and use, while effectively eliminating the need for grease or oil. By eliminating liquid lubricants, contamination and maintenance can also be reduced.


GRAPHALLOY Tin Based Babbitt materials can often replace plastics because they offer superior heat dissipation and will not melt or cold flow. In low temperature applications (-400° F /-205° C), these bearings solve lubrication problems caused by the viscosity of grease and oil that often prevents proper operation of equipment.


GRAPHALLOY Tin Based Babbitt provides all of the performance benefits of traditional babbitt materials without the environmental concerns. It can be used in potable water, food applications and traditional low temperature applications. GRAPHALLOY bearings and bushings are a proven solution for the most challenging plant maintenance and new equipment design.


Used in the manufacture of bushings, bearings and other components for machinery and process equipment, GRAPHALLOY materials are self-lubricating, impervious to temperature extremes (from -400° F to +1000° F/-205° C to 535° C) and thrive in harsh environments where other bearings fail. Graphite Metallizing Corporation has been producing GRAPHALLOY since 1913.

Wednesday, April 13, 2011

GRAPHALLOY® Helps Generate Reliable Geothermal Power

The Geysers is the largest geothermal power field in the world. Because geothermal power is constant (and nearly free), The Geysers have become one of the most reliable energy sources in Northern California. Currently, the Calpine Corporation owns and operates 19 of 21 power plants at The Geysers. Calpine and their predecessors have used GRAPHALLOY® to solve a critical pump application problem.

geyserCalpine is able to harness the superheated steam from The Geysers to generate 725MW of electricity. Despite its advantages, geothermal power has one limitation. Some of the 350 steam wells will eventually exhaust their supply of steam. In response to this problem, operators in the field reinject water into the ground to replenish the steam for power generation. 

However, one problem existed. Bearing materials were limited because of the temperature and corrosive environment of the injected water. To make this critical process viable, GRAPHALLOY bearings are used in the pumps injecting water condensed from the steam and treated wastewater back into the ground in the existing 58 injection wells. A special GRAPHALLOY grade was developed for this severe service.

GRAPHALLOY bearings have been a critical component of power generation at The Geysers for over 25 years. The hot, corrosive silt-ladened water required a special bearing material and GRAPHALLOY was, and is, the answer.

(Image courtesy of DOE/NREL, Credit - David Parsons)

Wednesday, March 30, 2011

High Temp GRAPHALLOY® Bushings Handle Hot, Harsh Environments

Self-lubricating GRAPHALLOY® bearings operate in high temperatures up to 750°F (400°C) in air and up to 1000°F (535°C) in non-oxidizing atmospheres. GRAPHALLOY, a graphite/metal alloy is uniform throughout and contains no oil or grease to harden or burn up in high temperatures or under load. Since they do not soften, gum, or seize in hot and harsh applications, as grease-lubricated and plastic bearings may, GRAPHALLOY bearings/bushings reduce maintenance, eliminate need for frequent replacements, and provide trouble-free operation.

Available in over 100 grades with specific properties to suit a wide range of operating conditions, GRAPHALLOY can be used in water, hydrocarbons, weak acids, and alkalies, and works submerged. Commonly used materials are copper, bronze, silver, and nickel.

GRAPHALLOY products include bushings, flange bearings, hanger bearings, pillow blocks, seals, case rings, thrust washers, wheel assemblies, and electrical contacts, and are available in custom designs or as standard components. Typical applications include ovens, furnaces, conveyors, dryers, dampers, pumps, and plating tanks. GRAPHALLOY has received FDA acceptance and can be steam cleaned without damage or performance reduction.


Thursday, March 17, 2011

GRAPHALLOY® Plays a Key Role in Geothermal Energy

Crucial to the Success of Pentane Pumps in Geothermal Power

Pentane is a low lubricity, low boiling point liquid. Whenever there is an upset, pumps in pentane service risk galling. Because of the nature of this pumpage, GRAPHALLOY® wear parts are selected to provide a margin of safety and prevent galling.

Why Pentane in Geothermal?
Geothermal power generation must operate with whatever temperature is found in a particular well. Water and steam work well at high temperatures. At lower temperatures, a "binary system" may sometimes provide better efficiency.

In a binary system, the hot fluid from the geothermal source is used to heat a second, lower boiling point fluid (in this case, pentane) to convert it to gas and drive a turbine. The nature of pentane allows the whole cycle (fluid to gas, drive the power generation turbine, and condense to fluid) to take place efficiently at a lower temperature.

At this location, a binary system is being used to squeeze additional power from the hot condensate leaving a primary water/steam turbine. Using an additional set of heat exchangers this energy is captured to heat low boiling point pentane and to drive an additional turbine. The pentane system harnesses more of the energy brought out of the ground.

Like getting something for nothing.

The Challenge
A major U.S. geothermal power plant experienced difficulties with their pentane feed pumps. The pumps are Goulds model 12RJHC-7 stage vertical can pumps. They have a shaft diameter of 1.5 inches with an 18 inch diameter suction can. Each pump is driven by a 125 HP, 1800 RPM electric motor.

Service Conditions
Flow: 966 GPM
Total Developed Head: 476 Feet
Specific Gravity: 0.58 SG
Temperature: 123° F/51° C
Bearings: originally fitted with bronze bearings

The plant's pentane pumps were experiencing deflections on start-up and shut-down. This caused the rotating sleeves to come into contact with the bronze bearings. Because of pentane's poor lubricity, this can cause severe wear or galling and risks damage or seizing of the pumps.

The Solution
To eliminate this problem, the maintenance staff consulted with the engineers at Graphite Metallizing and converted the bowl and line shaft bearings to a GRAPHALLOY bronze grade. The upgrade was a relatively simple procedure allowing the pumps to return to service quickly. The pumps have been in operation without issues for over 3 years.

GRAPHALLOY bearings have been improving the operation of pumps in difficult applications for almost a century. Graphite Metallizing Corporation, the manufacturer of GRAPHALLOY bearings, has been supplying products to companies involved in the production of renewable energy for 50+ years.

Tuesday, March 8, 2011

Screw Conveyor Bushings for Reliable Service

GRAPHALLOY® Type 1017 Self-lubricating Split Bushings, available from Graphite Metallizing Corp., are ideal for screw conveyor applications.  

GRAPHALLOY bushings with long life and low friction characteristics have a history of solving bushing problems for screw conveyors. These bushings contain no oil to contaminate the conveyed materials and are particularly suitable for screw conveyor installations including agitator or batch mixers. Type 1017 bushings are split to provide for easy installation along the conveyor.  

Type 1017 bushings can withstand dust, chemical attack, caustic liquids and high temperature environments. They provide superior performance in continuous duty operations and in applications where maintenance intervals are infrequent, or where useful life must be prolonged. 

GRAPHALLOY, a graphite/metal alloy formed from molten metal, graphite and carbon, is insoluble in most industrial liquids and is not affected by submersion in most acids, alkalies, hydrocarbons or liquid gases.  GRAPHALLOY does not deform under load and maintains dimensional stability.

GRAPHALLOY products work where oil-based lubricants oxidize and where plastic bushings fail or prove troublesome. GRAPHALLOY bushings are applied in refineries, paper mills, waste-to-energy plants, glass plants, steel mills and power plants.  Grades are available for temperatures to 750˚F (400˚C) in air, and special grades provide reliable service up to 1000˚F (535˚C) and higher in non-oxidizing atmospheres.

GRAPHALLOY bushings and bearings are a proven solution for even the most challenging plant maintenance and new equipment design requirements.

Wednesday, February 23, 2011

Food Manufacturer Asks "If Your Bearings Are As Good As You Say They Are..."

GRAPHALLOY® was presented with a challenge from one of the largest food manufacturers in the country. Their frozen food division, specializing in frozen pizza, was experiencing difficulties with the operation of their bakery ovens. The conventional oil-lubricated bearings being used in the ovens were lasting only one week. The customer was replacing 16 to 20 burned-out bearings every seven days for over one year.

As a prime supplier to the school lunch program, this food manufacturer was producing pizza in high volume. They were baking two shifts per day plus a third shift for cleaning, seven days a week. To maintain this level of production, the bakery was using two continuous belt-type ovens with an operating temperature of 525° F (275° C).

The bakery had problems keeping the belt tracking straight as it rolled through the long ovens. On several occasions, the belts and entire sections of the oven were damaged when the belts veered off the track. The customer devised a system of cam follower roller guides to keep the belts on track. The cam followers were mounted on an adjustable bracket with slotted holes to keep the rollers in contact with the belt.

Despite these efforts, the bearings continued to fail. This customer eventually contacted us through our website (www.graphalloy.com) with an email that began, "If your bearings are as good as you say they are...". Sensing their frustration, the local sales representative for Graphite Metallizing met with the customer to evaluate their problem and recommend a solution. Within a few weeks, GRAPHALLOY 1217-24-120.3 cam followers were installed. More than four months later, these cam followers were not showing any signs of wear.

Once again, GRAPHALLOY has exceeded expectations.

In addition to bakery ovens, GRAPHALLOY bearings may be used in dryers, grills, bottling plants and packaging equipment - anywhere grease and oil might fail. GRAPHALLOY bearings also withstand steam cleaning operations without any loss of performance.