Graphite Bearings and Bushings

GRAPHALLOY® Turns Lead-Free Into Problem-Free

2012-01-12T14:33:00.001-05:00

In an effort to address environmental concerns, a manufacturer of fluorescent lighting tubes initiated a program to remove lead from the glass. When this move to lead-free glass caused manufacturing problems,GRAPHALLOY® came to the rescue.

Lead was beneficial to the production process. The move to lead-free glass caused a problem with the bushings in the machine that flared the end of the tube and prepared it to attach and seal to the end plugs.

The lead in the glass had provided additional lubrication and kept the units from “gumming up” and sticking. With lead-free glass, the maintenance crew went from rebuilding the units once a year to once every three months.

The plant engineer contacted GRAPHALLOY engineers who then designed copper-grade self-lubricating GRAPHALLOY bushings to test in the machine. The GRAPHALLOY bushings were installed and the machine ran for three months with no problems. At that time, the plant placed a production order for an additional 200 pieces.

The machine fitted with GRAPHALLOY bushings has been operating for over one year without failure...four times the life of the original bushings.

The success of these GRAPHALLOY high temperature bushings provided this plant with better performance and significant cost savings. It demonstrates the potential for GRAPHALLOY upgrades in other manufacturing applications.

GRAPHALLOY® Attending International Exhibition in 2012

2012-01-03T15:51:00.003-05:00

SEPEM Industries
Practical solutions on operation, maintenance and development to energy, chemicals, wood and furniture, metallurgy, plastics, rubber and various other sectors. For more information about this conference, please click here.

January 31, 2012 - February 2, 2012
Avignon Sud Parc des expositions
Avignon, France

High Temperatures Pose No Problem for GRAPHALLOY® 845 Inserts

2011-11-16T15:12:00.000-05:00

Graphite Metallizing Corporation announces GRAPHALLOY® 845 Spherical Inserts as a replacement for traditional ball bearings in many hightemperature applications. GRAPHALLOY, a graphite/metal alloy, is designed to operate without lubrication which makes 845 Spherical Inserts especially suited for operations where temperatures can reach — or exceed — 750°F (400°C).

GRAPHALLOY 845 Spherical Inserts are intended for use in standard pillow and flange blocks without the need to alter or redesign equipment. 845 Spherical Inserts are used in a variety of high temperature applications including ovens, furnaces, conveyors, glass lehrs, dampers, dryers as well as other environments where oil and grease cannot be used. Metric shaft sizes and stainless steel housing and inserts are available along with FDA accepted grades.

According to Eben Walker, General Manager of Graphite Metallizing Corporation, “Using GRAPHALLOY 845 Spherical Inserts has proven time and time again that significant ROI, cost savings and reduced maintenance can be achieved, especially in difficult applications where high temperatures are a concern.“

Other benefits of GRAPHALLOY include a low coefficient of friction and dimensional stability. Like all GRAPHALLOY products, 845 Spherical Inserts will not soften at high temperatures or extrude under load. GRAPHALLOY bushings also operate at longer intervals without the need for frequent replacement or maintenance which helps reduce costly downtime.

GRAPHALLOY is also an excellent choice for any application where service and maintenance tasks are cumbersome or difficult to perform. GRAPHALLOY is a proven solution for even the most challenging plant maintenance and new equipment design.

For more information about GRAPHALLOY products, visit http://www.graphalloy.com/.

GRAPHALLOY® at Heat Treat Conference in Cincinnati

2011-10-17T14:32:00.003-04:00

Graphite Metalllzing Corporation will be exhibiting at the 2011 ASM Heat Treating Society Conference and Exposition from October 31 - November 2, 2011. This event will be held at the Duke Energy Convention Center, Cincinnati, Ohio.

Visit us at Booth #1925.

For more information about the 2011 Heat Treating Society Conference, click here.

Bearings That Can Handle The Heat

2011-10-13T15:23:00.000-04:00

The bearings on the dampers controlling airflow to two 535-MW coal-fired units at a power plant couldn’t handle the heat. High-temperature bearings solved the problem.

The inlet-air section of a utility boiler is a harsh environment for the dampers that control the flow of preheated air into the combustors. Over time, the hot air dries out the lubricant in the metal bearings, or roller elements, that control the movement of the dampers, causing the dampers to seize.

This was a problem at the Sioux Power Plant of Ameren UE (Union Electric), near St. Louis. The plant has two 535-MW, coal-fired units, each of which has 10 cyclone burners. There are two dampers on each burner -- a control damper and a shut-off -- for a total of 40 secondary air dampers. “On average, we had a bearing problem about every two months,” says James Riegerix, general supervisor at the plant.

Ameren has solved the problem by replacing the lubricated steel bearings with self-lubricating bearings made from GRAPHALLOY®, a graphite/metal alloy by Graphite Metallizing Corp., Yonkers, N.Y. All of the bearings for one boiler were replaced in the spring of 2004, and those in the other unit were replaced a year later. Both installations were completed during planned plant outages, which normally are scheduled every two years. So far, there have been no problems with the new bearings, says Riegerix.

He adds that when the changeover was done, the installers found a single bearing from Graphite Metallizing that had been put in a few years earlier. It was still in such good condition it was not changed.

Read more...

GRAPHALLOY® Provides Pillow Block Solutions for Confined Areas

2011-09-19T15:59:00.004-04:00

If you have conveyor applications with closely spaced roll or other confined applications, GRAPHALLOY® can provide a solution. The 845 and the 448 series pillow blocks are available with a tapped base, allowing for installation in areas where space is a factor. The 845 series provides a solution for normal duty applications while the 448 series is designed for heavier duty requirements.

Both designs provide the same advantages of all GRAPHALLOY pillow blocks:
• Self lubricating; requiring no grease or oil
• Work in temperatures ranging from -400°F to +1000°F
• Available in FDA accepted grades
• Can be used submerged
• Survives harsh chemicals including wash down applications

• Self aligning design

• 845 series interchanges with traditional ball bearing design

Typical applications include ovens/furnaces, conveyors, dryers, submersed screens, food processing and more. If you have an application where these or other GRAPHALLOY products can be problems solvers, contact one of our application engineers.

GRAPHALLOY® at the Turbomachinery Symposium

2011-09-08T16:33:00.005-04:00

Graphite Metallizing Corporation will be at the 40th Turbomachinery Symposium on September 12 -15, 2011 at the George R. Brown Convention Center, Houston, TX.

Visit us at Booth #1707.

Click here for more information about this symposium.

GRAPHALLOY® Stainless Steel Cam Followers for Wet or Submersible Applications

2011-08-22T14:43:00.012-04:00

Graphite Metallizing Corporation announces the availability of GRAPHALLOY® stainless steel cam followers for wet or submersible applications. These stainless steel cam followers are corrosion resistant and survive wash down and steam, eliminating the problems experienced with traditional cam followers.

GRAPHALLOY® cam followers do not contain oil or grease to harden, burn up, contaminate or wash away. They are designed to handle moderate loads and speeds of up to 100 RPM and provide reliable performance in temperatures up to 750° F (400° C).

Typical applications include bakery and industrial ovens, steel mill equipment, glass plants, conveyors, kilns, stokers and substrate dryers. GRAPHALLOY® cam followers also perform well in low temperature environments of -100° F (-75° C).

GRAPHALLOY®, a graphite/metal alloy, is a uniform, solid, self-lubricating material. GRAPHALLOY® cam followers will not deform under load, maintain dimensional stability and provide a constant low coefficient of friction for improved wear. GRAPHALLOY® cam followers are especially suitable in applications where lubrication or maintenance tasks are cumbersome, difficult or impossible to perform.

Graphite Metallizing's GRAPHALLOY® cam followers are made to industry-standard dimensions. Metric sizes and special or custom designs are also available.

GRAPHALLOY® Eliminates the Need for Grease and Keeps the Ovens Running

2011-08-11T13:58:00.000-04:00

Glass ceramic is ideal for use in a variety of appliances because it is resistant to temperature extremes. This unique material is well-suited for use in cooktops and doors for microwave ovens and fireplaces.

Constant greasing and frequent failures drove a major manufacturer of glass ceramic to seek a better solution. The manufacturer was experiencing problems with their production ovens and dryers. Stud-type cam followers with grease lubrication were being used. The cam followers needed replacement after six months because the grease was failing at the high temperature (428° F/220° C).

After learning about the run dry, self-lubricating properties of GRAPHALLOY® bearings, the manufacturer contacted Graphite Metallizing Corporation and requested a design solution. Eight standard GRAPHALLOY metric cam followers were installed for testing.

After five months, this manufacturer had already realized significant savings because of reduced maintenance costs and the elimination of high cost, high temperature grease. They were so pleased with the performance of the GRAPHALLOY cam followers that they ordered an additional 200 to retrofit their current ovens.

These GRAPHALLOY cam followers have now been in operation for over one year without the need for replacement or the constant greasing of the original equipment.

The manufacturer plans to retrofit additional ovens in plants worldwide with GRAPHALLOY cam followers.

GRAPHALLOY® No-Lead Bronze Solves Difficult Application Problems

2011-07-20T14:22:00.000-04:00

Graphite Metallizing Corporation has developed several bronze GRAPHALLOY^® grades that do not contain lead. These essentially lead-free formulations are used in bearings and bushings where the potential for lead contamination is unacceptable.

Applications include deep-well and potable water pumps, and food-processing equipment such as ovens and conveyors. GRAPHALLOY no-lead bronze has been accepted by the FDA as suitable for many food-grade applications.

The family of no-lead bronze, developed by Graphite Metallizing, offers all the advantages of the leaded bronze GRAPHALLOY without any sacrifice in performance. GRAPHALLOY bushings and bearings are non-galling and are dimensionally stable even when submerged, under load or experiencing wide temperature swings.

There are GRAPHALLOY grades that can withstand temperatures ranging from cryogenic to +1000˚F. Because GRAPHALLOY bushings and bearings are self-lubricating, they are suitable for applications where maintenance operations are infrequent or difficult.

Stainless Steel Pillow Blocks with GRAPHALLOY® Bushings Solve Underwater Bearing Problems

2011-06-28T16:22:00.004-04:00

Graphite Metallizing Corporation has introduced a series of stainless steel pillow blocks fitted with self-lubricating GRAPHALLOY® bushings that resist attack from water and water-soluble chemicals, do not require lubrication and are corrosion-resistant.

GRAPHALLOY Stainless Steel Pillow Blocks are a key component of submerged physical therapy and conditioning equipment used by professional sports teams and college athletic departments. The ability of GRAPHALLOY bearings to provide trouble-free underwater operation without any lubrication has been a key factor in the success of this type of equipment, including underwater treadmills.

GRAPHALLOY is a graphite-metal alloy that has exceptional chemical, mechanical and tribological properties that provide a constant, low coefficient of friction. As a result, GRAPHALLOY works where traditional bearing materials often fail. In addition to being self-lubricating, GRAPHALLOY withstands high-temperatures up to 1000˚ F, performs well under cryogenic conditions, can survive dry running pumps and maintains its integrity even when submerged in hostile liquids such as acids, alkalies, hydrocarbons, black liquor, and liquid gases.

GRAPHALLOY wear components improve reliability under conditions such as low speed operation, frequent starts and stops and switchovers from standby to continuous running. FDA accepted grades are available for food applications.

GRAPHALLOY products are available in standard designs including cylindrical bushings with or without grooves, single, double-flanged, split and metal backed bushings as well as pillow block and flange units. In addition, a high percentage of the products are produced to meet custom requirements.

GRAPHALLOY® Self-Lubricating Bushings for High Heat, Low Maintenance and Reduced Downtime

2011-06-15T14:52:00.000-04:00

Graphite Metallizing Corporation announces additional sizes of the GRAPHALLOY® 453 Family of Self-Lubricating Bushings. These bushings are for severe industrial applications where temperatures reach 750° F (400° C) or higher. GRAPHALLOY, a graphite/metal alloy, bushings are designed to operate without lubrication.

The 453 Bushings have proven to be successful in a variety of high temperature applications including bakery ovens, heat treat ovens, furnaces, conveyors, overhead paint lines, glass lehrs, louvers, dampers, valves as well as other environments where oil and grease cannot be used. Applications can experience improved performance through the use of GRAPHALLOY materials.

Among their many advantages, GRAPHALLOY bushings operate at longer intervals without the need for maintenance, which reduces costly downtime. They are an excellent choice for applications where service and maintenance tasks are cumbersome or difficult to perform. Additional benefits of GRAPHALLOY include a low coefficient of friction and dimensional stability. The 453 Bushings, like all GRAPHALLOY products, do not soften at high temperatures or extrude under load. Installations of these bushings have operated for more than 10 years without maintenance.

GRAPHALLOY can be the solution to the toughest bearing, bushing, thrust washer, cam follower, or pillow block bearing design problem. It is available in over 100 grades with specific properties that meet a wide range of engineering solutions and specifications. FDA accepted grades of GRAPHALLOY are available for food contact equipment. NSF® International certified two grades of GRAPHALLOY material for use in municipal well pumps and water treatment plant applications.

In some applications, GRAPHALLOY bearings have operated for up to 20 years without maintenance. Standard designs are available but most GRAPHALLOY products are custom designed to the unique requirements of the specific application.

Graphite Metallizing Corporation is ISO certified and has produced GRAPHALLOY since 1913. For additional information about Graphite Metallizing and its products, please visit us online at http://www.graphalloy.com/index.htmlor call 914-968-8400.

Steel Mill Customer Orders Largest GRAPHALLOY® Split Pillow Block Bushing Ever Made

2011-06-01T15:47:00.000-04:00

A Graphite Metallizing steel mill customer recently installed 12 “super-sized” GRAPHALLOY^® bushings for the main drive shaft in their quench tank.

The Model 478 GRAPHALLOY split pillow block design has a bore ID of 6.00 inches — the largest ever produced by Graphite Metallizing. These pillow blocks are used to support the sprockets that drive the chains pulling molten billets through the quench tank. Each of the dozen pillow blocks that the mill ordered weighs more than 250 lbs. and must function under difficult operating conditions: complete submersion in heated, contaminated water while supporting 10,000 lb. loads at 10 RPM.

GRAPHALLOY bushings can withstand temperatures ranging from cryogenic to 1000° F/535° C) and are dimensionally stable even when submerged or under load. They can be used to solve difficult application problems involving high temperatures, as well as acidic, corrosive and wash-down environments. Because of their long life and self-lubricating qualities, they are especially suitable for installations that cannot be accessed easily, or where performing regular maintenance is difficult.

Graphite Metallizing Corp., established in 1913, produces GRAPHALLOY a graphite/metal alloy bearing material used in the manufacture of self-lubricating bearings and components for machinery and process systems.

GRAPHALLOY® Takes a Stand Against Heat and Sand

2011-05-25T14:57:00.000-04:00

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.

GRAPHALLOY® Bearings for High Temperature, Environmentally Sensitive Designs

2011-04-28T14:29:00.000-04:00

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.

GRAPHALLOY® Helps Generate Reliable Geothermal Power

2011-04-13T15:12:00.002-04:00

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.

Calpine 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)

High Temp GRAPHALLOY® Bushings Handle Hot, Harsh Environments

2011-03-30T16:15:00.001-04:00

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.

GRAPHALLOY® Plays a Key Role in Geothermal Energy

2011-03-17T15:39:00.004-04:00

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.

Screw Conveyor Bushings for Reliable Service

2011-03-08T16:38:00.000-05:00

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.

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

2011-02-23T14:11:00.002-05:00

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.

Self Lubricating Bushings Offer Dependable Performance

2011-02-16T15:01:00.000-05:00

Graphite Metallizing Corp. announces the 117 Series of GRAPHALLOY® bushings which deliver dependable performance in high temperature applications. GRAPHALLOY, a graphite/metal alloy, is formed from molten metal, graphite and carbon. It is a uniform, solid, self-lubricating bushing and bearing material. The 117 Series excels in bakery ovens, heat treat furnaces, glass plants, potato chip and bagel factories, dampers, stokers and wherever grease, oil and plastic bushings fail or prove troublesome.

In addition, the 117 Series of GRAPHALLOY bushings provides a convenient, pre-engineered solution for plant maintenance and new equipment design requirements. The 117 Series is available in two primary grades for high temperatures, both with FDA acceptance as well as for low temperatures.

All GRAPHALLOY products work where oil-based lubricants oxidize or where plastics fail. Many grades are suitable for temperatures to 750°F in air, and special grades provide reliable service up to 1000°F and higher in non-oxidizing atmospheres.

Specialy Materials Help Improve Pump Reliability and Save Energy

2011-02-09T14:15:00.001-05:00

GRAPHALLOY® allows for reduction of clearances

Efficiency degradation in pumps can be related to three areas. Worn clearances between the wear rings of the impeller and the casing can increase leakage and drop the volumetric efficiency of the pump. Rough, rusty and damaged internals increase friction, reducing hydraulic efficiency. Finally, rubs, galling, friction in the mechanical seals and bearings, can result in the reduction of mechanical efficiency.

Together, these three pumping problems reduce the available flow, lower pressure and/or require more power consumption. These three issues also make a pump less reliable. Pump efficiency and reliability are often intertwined.

Click here to continue reading this article from Pumps & Systems

GRAPHALLOY® at Rotating Equipment Reliability Seminar

2011-02-07T14:48:00.000-05:00

Graphite Metalllzing Corporation will be exhibiting at the Rotating Equipment Reliability & Vibration Analysis Seminar on February 8, 2011. This event is sponsored by the Triplex Chapter of the Vibration Institute and will be held at the MCM Elegante Hotel in Beaumont, Texas.

GRAPHALLOY® at International Exhibitions

2011-02-01T16:18:00.001-05:00

Graphite Metallizing Corporation will be sponsoring a booth at the following international exhibit:

Middle East Turbine Symposium (METS)
February 13 -16, 2011
Doha, Qatar
Booth #520

Graphite Metallizing Corporation just returned from the SEPEM Industries exhibition in Douai, France.

GRAPHLON GM 860® — An Abrasion-Resistant Pump Bushing Material

2011-01-27T15:26:00.000-05:00

GRAPHLON GM 860® is an abrasion-resistant bushing material that protects pumps and helps prolong pump life. Developed by Graphite Metallizing, the material is a tough, polymer/graphite-based alloy used in the manufacture of pump bushings and other critical-wear parts.

GRAPHLON GM 860® provides exceptional abrasion resistance in harsh environments, has high compressive strength and can handle temperature extremes from -100˚ F to 300˚ F (-75˚ C to 150˚ C). It is inert to most noxious chemicals, including acid mine water, hydrogen sulfide and jet fuel, and does not swell in water.

GRAPHLON GM 860® was developed as a replacement for traditional pump materials which are prone to damage from highly-abrasive suspensions. River water pumping stations and down hole sump pumps are two examples of key applications. The material also performs exceptionally well under both dry running and severe-duty abrasive-contaminated conditions.

Graphite Metallizing Corp., established in 1913, produces GRAPHALLOY® a graphite/metal alloy bearing material used in the manufacture of self-lubricating bearings and components for machinery and process systems.

GRAPHALLOY® Cam Followers For High Temperature Applications

2011-01-04T16:16:00.000-05:00

Graphite Metallizing Corporation announces GRAPHALLOY® high temperature cam followers which outperform ordinary grease or oil-lubricated cam followers in high temperature applications.

GRAPHALLOY cam followers do not contain oil or grease to harden, burn up, contaminate or wash away. They are designed to handle moderate loads and speeds of up to 100 RPM. They provide reliable performance in temperatures up to 750°F (400°C).

Typical applications include bakery and industrial ovens, steel mill processing lines, glass plants, conveyors, kilns, stokers and substrate dryers. GRAPHALLOY cam followers also perform well in low temperatures environments of -100° F and below (-73°C and below) and in wet or submerged applications.

GRAPHALLOY, a graphite/metal alloy, is a uniform, solid, self-lubricating material. GRAPHALLOY cam followers will not deform under load, maintain dimensional stability and provide a constant low coefficient of friction for improved wear. GRAPHALLOY cam followers are especially suitable in applications where maintenance tasks are cumbersome, difficult or impossible to perform.

Graphite Metallizing's GRAPHALLOY cam followers are made to industry-standard dimensions. We can also supply metric sizes and special or custom designs.

GRAPHALLOY® Bushings For Clean Geothermal Energy

2010-12-15T15:32:00.000-05:00

GRAPHALLOY® Bushings Keep Geothermal Brine Pumps Pumping

GRAPHALLOY bushings were made to conquer harsh environments. And what test could be tougher than a brine pump at a geothermal power plant?

Geothermal power is an important source of renewable energy because it is cost effective, reliable, sustainable and environmentally friendly. One U.S. power plant - a large commercial producer of geothermal energy - was experiencing major problems with its geothermal brine pumps. Geothermal brine is highly corrosive and was causing the 416SS Boron coated bearings to fail and, as a result, service life was severely reduced.

The pumps are Johnston Pump Model 24.5 x 8 x 10 Type JTCF (Discharge Head and nine stages of Type 12ES Bowls) with the following service conditions:

Flow: 1300 GPM
Total Developed Head: 485 feet
Temperature: 350° F - 400° F/180° C - 200° C
Specific Gravity: 0.89 SG

The maintenance staff at the plant tried several other bearing materials, including bronze and a type of PEEK plastic. Neither provided acceptable performance.

In 2008, the staff converted one of the brine pumps to Nickel GRAPHALLOY because they knew of its resistance to corrosion and its non-galling properties.

Results have exceeded expectations. In fact, the Maintenance Staff recently converted two additional brine pumps to Nickel GRAPHALLOY.

GRAPHALLOY bearings have been improving the operation of pumps in difficult applications for almost a century. Graphite Metallizing, makers of GRAPHALLOY, has been supplying products to companies involved in the production of clean, renewable energy for many years. Because of the extreme nature of the environments required to generate geothermal power, the use of traditional bearings often proves difficult. Yet GRAPHALLOY is tough enough for these applications.

Is GRAPHALLOY a good fit for your pump application? Our engineers can walk you through the key advantages of these bearings and discuss the right GRAPHALLOY solution for you.

New GRAPHALLOY® Model 163 Pillow Blocks are Long-Wearing

2010-11-30T16:06:00.006-05:00

GRAPHALLOY^® Pillow Blocks are Versatile and Eliminate the Need for Lubrication

Graphite Metallizing Corp., the manufacturer of self-lubricating GRAPHALLOY bushing materials, has developed Pillow Block Assemblies that can handle high temperature and submerged environments that do not permit the use of grease and oil.

GRAPHALLOY Pillow Block Model 163 is a rugged, easy-to-install design for moderate speed applications that will operate successfully under high or low load conditions. This heavy-duty unit is available in cast iron or stainless steel. A cast iron split-angle housing is also available.

Pillow Block Model 163 is suitable for high temperature applications such as ovens, drag-line conveyors and dampers. This pillow block also performs well in wet applications such as wash downs and submerged applications like plating tanks and industrial washers.

All GRAPHALLOY pillow blocks have a low coefficient of friction, can withstand submerged conditions and are chemically resistant and non-galling. Since the self lubricating properties of GRAPHALLOY are constant throughout the material, these pillow block assemblies will provide long life and reliable operation.

Graphite Metallizing has other pillow block models that meet a variety of speed and load conditions. They are available in a wide range of sizes and housing types, in two and four bolt arrangements as well as in solid, split and self-aligning configurations. Flange and custom models are also offered.

You Need GRAPHALLOY® In Your Freezer

2010-11-16T16:34:00.009-05:00

A seafood processing plant in the Southeast was running a conveyor in their freezer area to "flash-freeze" fresh seafood. The environment is a difficult one: the temperature is cold (28° F/-2° C) and wet and the system requires frequent wash down. The conveyor bearings were being replaced every other month.

The plant maintenance superintendent contacted GRAPHALLOY about the problem. It was determined that the current bearings were not holding lubrication because of the cold, wet conditions and, as a result, breakdowns were occurring frequently.

GRAPHALLOY 4-bolt flange block assemblies were installed and have been running successfully for more than six years. The plant has since placed orders for additional flange assemblies for their freezer conveyor and fish wash down lines. GRAPHALLOY continues to work with the plant maintenance superintendent to identify other opportunities on their fish processing conveyors.

The self-lubricating qualities of GRAPHALLOY bushings are well-suited to cold, wet applications. Once again, GRAPHALLOY bearings work when others fail.

GRAPHALLOY® Solves a Biodiesel Fuel Development Problem

2010-11-04T14:33:00.007-04:00

A machinery design company in Alabama was using steam, high temperature (up to 1000° F/535° C) and an inert atmosphere to convert wood chips and used cooking oils into biodiesel fuel. Because standard bearings were not an option in this environment, GRAPHALLOY^® provided a solution.

The production of biodiesel fuel is important because it is biodegradable, non-toxic, clean-burning and renewable. Additionally, it burns much cleaner than than petroleum-based diesel, creating about 60% less net carbon dioxide emissions. These factors make it an ideal fuel for buses, trucks and farm equipment.

This company's design uses several standard bushings as well as custom-sized bushings for their prototype machines. GRAPHALLOY's diverse mountings and extensive experience proved valuable in developing a solution for this difficult environment.

Alternative fuel manufacturing is a growing field due, in part, to efforts to decrease dependence on petroleum-based fuels. GRAPHALLOY will continue to be a valuable resource for these high-temperature applications.

GRAPHALLOY® Introduces NSF® Certified Grades For Pumps

2010-10-19T11:58:00.008-04:00

Used in Pump Bushings and Bearings for Vertical and Horizontal Pumps

Graphite Metallizing Corporation, the manufacturer of self-lubricating GRAPHALLOY® bushing materials, is pleased to announce that NSF® International, has just certified two grades of GRAPHALLOY material for use in municipal well pumps and water treatment plant applications.

The two newly certified GRAPHALLOY Grades are certified to NSF/ANSI Standard 61 - “Drinking Water System Components/Health Effects” - and approved in the category for Multiple Water Contact Materials (MLTPL) up to 180˚F.

NSF certification is the result of Graphite Metallizing’s rigorous product testing to ensure the highest quality GRAPHALLOY products for the market. These newly certified grades are used in the manufacture of pump bushings and bearings for both vertical and horizontal pumps.

GRAPHALLOY is currently the product of choice for many deep well water pump applications in the western U.S., Hawaii and around the world.

NSF International is the independent, not-for-profit/non-governmental organization that provides materials evaluation, standards testing and product certification services involving public health and safety issues.

Graphite Metallizing Corporation, a global leader in the manufacture of self-lubricating bushings and bearings for almost a century, produces GRAPHALLOY, a graphite/metal alloy bearing material used in the manufacture of self-lubricating bearings and components for pumps, machinery, and process systems.

GRAPHALLOY® Bearings FDA Accepted for Food Processing Applications

2010-10-04T11:59:00.009-04:00

Graphite Metallizing Corporation, the manufacturer of GRAPHALLOY^® bearings and bushings, announces that FDA accepted grades are available for food processing and commercial baking applications.

GRAPHALLOY, a graphite/metal alloy, is formed from molten metal, graphite and carbon. It is a uniform, solid, self-lubricating bushing and bearing material. GRAPHALLOY is widely used in bakery ovens, dryers, roasters, mixers, conveyors, freezers, sterilizers, grills, pumps, bottling plants and packaging equipment — anywhere grease/oil lubricated bearings or plastic bearings might fail.

Self-lubricating GRAPHALLOY bearings and bushings perform in temperature extremes of -450˚F to +750˚F and above (-240˚C to +400˚C and above) where conventional materials often fail. GRAPHALLOY bearings require minimal maintenance and can reduce downtime, resulting in uninterrupted production of food contact equipment. With a low coefficient of friction and high strength, GRAPHALLOY bearings deliver long life and are not subject to seizures, binding or sudden failure.

Equally important, GRAPHALLOY does not contain oil or grease and can be immersed in liquids without causing contamination of equipment or packaging. GRAPHALLOY bearings also withstand steam cleaning and pressure washing operations without any loss of lubrication or bearing performance.

GRAPHALLOY bushings are also used in municipal water systems, refineries, paper mills, waste-to-energy plants, glass plants, steel mills and power plants. Many grades are suitable for temperatures to 750˚F (400˚C) in air and special grades provide reliable service up to 1000˚F (538˚C) and higher in non-oxidizing atmospheres.

Submerged Pillow Blocks - 20 Years of Service in an Abrasive Environment

2010-09-16T13:39:00.040-04:00

GRAPHALLOY^® Pillow Blocks - Reliable in Wastewater Treatment

After two decades of reliable service, the GRAPHALLOY bushings in a wastewater treatment plant were replaced with new GRAPHALLOY bushings.

A large condominium complex in the Northeast maintains this wastewater treatment facility on its premises. Wastewater treatment is a chemical and biological process that removes contaminants from household sewage. This process produces wastewater and solid waste suitable for discharge back into the environment.

The condominium complex used a Rotating Biological Contactor (RBC), a type of mechanical aeration treatment system, to treat the wastewater. The RBC is a secondary treatment process that allows the wastewater to come into contact with a biological medium. This process removes pollutants from the wastewater before releasing it into a nearby body of water.

An RBC unit consists of a large disc with radial and concentric passages slowly rotating in a concrete tank so that the surface of the wastewater passing through the tank almost reaches the shaft. As a result, nearly 40% of the total surface area of the disks is always submerged in the ambient wastewater. The rotation and exposure to oxygen allows organisms to multiply and cause the biological degradation of organic pollutants.

This facility had two RBC systems - one of which was running at all times. Each system had GRAPHALLOY pillow blocks at either end and each pillow block contained GRAPHALLOY bushings that had been installed in 1988.

Using the imprint code from the outside of the casting, Graphite Metallizing was able to identify the pillow blocks used in the unit. The maintenance manager at the condominium complex removed two of the pillow blocks and drove the insert assemblies to the Graphite Metallizing manufacturing facility in Yonkers. Once the units were disassembled, the original bushings proved to still be functional after 20+ years of operation in the abrasive conditions. The old bushings were removed and new GRAPHALLOY bushings were manufactured and installed in the housing.

GRAPHALLOY provided reliable, long-lasting service in this difficult wastewater treatment application. The original bushings provided service 20+ years after installation.

Chemical Plant Experiences Bushing Failure in Gear Pumps

2010-09-02T10:25:00.011-04:00

The Competition Said "No" but GRAPHALLOY^® Said "Yes"

A chemical plant in Tennessee was experiencing rapid bushing failure in their gear pumps. These bushings were failing after only a few weeks of operation.

When plant representatives contacted this carbon bushing manufacturer about the problem, they were told that there was "no solution". The bushing manufacturer - our competitor - claimed that the viscosity of the polymer being pumped was simply too thick.

Unhappy with this response, the chemical plant engineers contacted Graphite Metallizing for assistance. After studying the problem, our engineers promptly responded by saying "yes, we can help" and that GRAPHALLOY bushings were the solution.

The pump that was failing was a positive displacement, herringbone-type gear pump with internal bushings lubricated by the pumped liquid. The pumpage is a polymer with heavy viscosity (150 -10,000 CPS) similar to a thick latex paint. The temperature can range from 80 degrees to 140 degrees F with a speed of 520 -1,750 RPMs and a load of 155 - 1,980 pounds. This pump has very high bushing loads because of the meshing gear forces. The calculated PV values were up to 500,000 - over four times the maximum recommended level for GRAPHALLOY in submerged services.

The GRAPHALLOY engineers provided a solution designed for applications involving the transfer of viscous liquids. Grade GM 119.3 bushings were recommended because of their load-bearing and corrosion-resistant capabilities. GRAPHALLOY engineers also recommended slight design changes to improve reliability.

The initial order was shipped to the customer and immediately installed.

The pumps fitted with GRAPHALLOY bushings have been operating for over one year without failure...six times the life of the competitor's bushings.

The success of these GRAPHALLOY bearings demonstrates the potential for GRAPHALLOY upgrades in chemical plants. If you have a pump that may benefit from GRAPHALLOY, please contact us with details about your application.

High Heat May Cause Problems for Traditional Bearings

2010-08-16T13:32:00.003-04:00

Steel and metals production creates problems for tradtional bearings because of the high heat and heavy loads. GRAPHALLOY® bearings provide a solution to these problems. Here is a really tough application:

The annealing furnace at a Pennsylvania metal manufacturer had an interior temperature in the range of 1200°F (650°C). Bearings supporting the pinch rolls were located outside the furnace walls and reached temperatures up to 750°F (400°C) due to heat transmitted through the furnace wall by the shaft.

The heat transmitted by the shaft through the oven wall to the bearing was causing lubrication failure. In addition, the movement (linear expansion) of the shaft caused problems well beyond the capability of any standard ball or roller bearing arrangement.

GRAPHALLOY high temperature bearings were installed in a metal adapter designed to fit the original bearing housings and solved the problem without a major redesign. With minimal investment, bearings failures and associated maintenance costs were reduced.

Even if your application isn't this tough, GRAPHALLOY bearings can solve your high temperature bearing problems.

New GRAPHALLOY® Stainless Steel Flange Block Suitable for Wet or Submersible Applications

2010-07-19T11:18:00.006-04:00

A new series of GRAPHALLOY® self-lubricating bushings mounted in stainless steel flange blocks is now available from Graphite Metallizing Corporation. The new series combines the corrosion resistant and self-lubricating properties of GRAPHALLOY with the application and installation versatility of a flange block.
GRAPHALLOY Stainless Steel Flange Blocks are available in 2-bolt and 4-bolt configurations,come in a wide range of base dimensions, and can accommodate shaft diameters from .5" (12.7 mm) to 3.75" (95.2 mm).

GRAPHALLOY is suitable for temperatures of 750°F/399°C and above in non-oxidizing environments or with oxidation -resistant grades.

GRAPHALLOY Stainless Steel Flange Blocks provide increased reliability and years of trouble-free operation. These flange blocks deliver lifetime cost and operating advantages in high temperature ovens, low speed and stationary applications such as dampers, and other hard to lubricate environments - all places where other bushings will not operate.

Go Green with Graphalloy®

2009-05-07T17:00:00.003-04:00

GRAPHALLOY^®: Finds Its Place In Renewable Energy

GRAPHALLOY bearings are helping to solve the world's energy needs. The advantages of alternate power sources are well-documented. However, because of the extreme nature of the environments required to generate power, it often becomes impossible to use traditional bearings. For years, Graphite Metallizing has been supplying products to companies involved in the production of clean, renewable energy. GRAPHALLOY has proven to be tough enough for these applications. Here are a few examples:

Tidal Power
Tidal power provides an inexhaustible source of renewable energy. A company in New England was seeking low maintenance bearings for a turbine shaft suspended forty feet below the ocean surface. As the tides move in and out, the turbines spin and generate power. GRAPHALLOY bearings proved ideal for this application because they operate successfully in submerged conditions and tolerate abrasive environments like salt water.

Geothermal Power
Geothermal power offers an unlimited source of non-polluting power. GRAPHALLOY provided a solution to the largest geothermal power field in the world by developing a special grade bearing for this severe service. After 25 years, GRAPHALLOY bearings continue to be a critical component of geothermal power generation.

Solar Power
Solar power has proven to be the "ultimate" in renewable energy. GRAPHALLOY bearings are being used in this high temperature application allowing panels to slowly follow the sun while generating high temperature steam.

Graphalloy finds a role in virtually every industry. When you have a tough bearing problem - Graphalloy has probably already found a solution. Call/ email their engineers. http://www.graphalloy.com/

Pumps for Ethylene service

2009-03-24T16:31:00.003-04:00

GRAPHALLOY® Fitted Pumps
for Survival in Tough Services

Pumps are a major GRAPHALLOY application. The unique properties of GRAPHALLOY enable pumps to run-dry and to survive upsets and flashing that shut-down ordinary pumps.

One Gulf Coast refinery has saved between $150,000 and $300,000 in annual repairs by converting four pumps in ethylene service to GRAPHALLOY. These 19-stage vertical pumps operate at 3560 rpm.

Ethylene is a very light hydrocarbon that creates problems in pump operation. Because of its low viscosity, ethylene provides minimal lubrication to the rotating parts of the pump. As a result, these pumps are prone to failure. The pumps in this Texas refinery were failing two to four times a year at an average cost of $75,000 per pump.

The OEM pump repair shop recommended GRAPHALLOY wear parts based on their success retro-fitting other ethylene pumps. GRAPHALLOY allows the rotating parts to contact without the danger of galling and seizing.

Although it was slightly more expensive than the original metal wear parts, GRAPHALLOY provided a significant cost-savings over composite plastics. The refinery engineer recognized the benefits that GRAPHALLOY could provide and approved the conversion.All four pumps were retro-fitted with GRAPHALLOY. In the three years since their installation, none of the converted pumps have failed. In addition, measurement of discharge pressure showed that the clearances had not opened up in that time.This GRAPHALLOY success in ethylene service demonstrates why so many pump users choose GRAPHALLOY for their toughest services. Ordinary fitted pumps do not allow for run-dry conditions and will not survive upsets and flashing. The unique features of GRAPHALLOY permit dry starts, survive frequent loss of suction, and extend life for continuous service

Replacing leaded bronze in pumps with Graphalloy®

2009-01-07T15:38:00.008-05:00

An engineer writes:

Asarcon 520 was a lead impregnated bronze used for sleeve bearing in horizontal split pumps. I have not seen it in use since my days at Worthington Pumps in the late 70’s. It was a material highly specified by the marine industry for on board ships, boiler feed pumps and fire pumps. As you can imagine, lead impregnated bearings were capable of running for short periods of times un-lubricated without the rotor disintegrating. The material was readily available in bar stock, however with the issues associated with lead contamination today, I do not believe it is available in the market any longer. To make sure, I would call the local bearing distributor or and bar stock suppliers and see if a similar material is available under some other name.

Years later, while I worked for Exxon as a Rotating equipment engineer we began using graphite/metal Graphalloy (graphalloy- http://www.graphalloy.com/html/products.html) sleeve bearing for pumps and Thorlon for the slower running centrifuges. We retrofitted some old packing pumps with mechanical seals that operated in hot oil services. These pumps, by design, depended on the packing for shaft support. In order to support the shaft and allow the mechanical seal to live, I installed steel encased Graphalloy (with spiral grooves to convey cooling pumpage) between the bearing housing and the old packing box. This eliminated the run out and allowed the seals to run true and consequently not leak. The Graphalloy material can be used in plain stock or encased in a steel sleeve to add strength, depending on need. In either case you must calculate the loads to assure that the bearing is appropriately designed, can support the shaft loads and you do not located your support at a node in the flexural curve.

Luis

How will Graphalloy handle our jet fuel pump application?

2008-12-26T11:42:00.000-05:00

The principal bearing issue for Jet fuel is its very low specific gravity which makes jet fuel a poor lubricant.

Graphalloy bearings have many applications in very low gravity pumpages (lng, ethane, propane, benzene, CO2 etc.). Graphalloy is excellent for these applications because in these low specific gravity fluids Graphalloy provides a margin of safety allowing moving parts to contact without galling or seizing.

We have a history with aircraft fuel gear pumps (from memory I think these go back to the 60's). Our primarily pump business is in high HP centrifugal boiler feed and process pumps (vertical and horizontal) where low lubricity, flashing or run dry conditions are a possibility. Graphalloy bearings will allow the pump to survive an upset. So we have lots of related experience and are confident that the materials can handle a jet fuel pump but we encourage you to do you own testing in as close to real world environment as possible.

We mostly supply finished bearings/bushings and generally these are custom sized for a specific manufacturer's equipment. Pumps are a large part of our bushing applications. The key Graphalloy material advantage is the ability to run dry or in very light fluids (jet fuel for example) without galling. This permits the pump to run dry for a period and then re-establish pumping without failing. (FYI http://www.graphalloy.com/html/pump.html ).

For a metal pump, the usual design is to install, with a press fit, directly into the housing of the pump. The bushings can be supplied with a metal backing but this is normally not necessary. One advantage to the press fit installation directly into the housing of the pump is that as the temperature of the housing changes the bearing can be designed to maintain both secure mounting and a constant clearance to the shaft over a wide range of operating conditions.

In order to proceed to a design, our engineers will need: pump cross sections and dimensions on housing and shafts, materials of construction, rpm, expected loads and pumpages.

How does Graphalloy compare to Tungsten Carbide

2008-12-18T17:00:00.004-05:00

A reader wrote to ask about the comparison of Tungsten Carbide to Graphalloy.

As you know Tungsten Carbide is an extremely hard, brittle material. As a bearing, it resists wear from abrasives.

Graphalloy is much softer, but can last longer running dry (without lubrication). However, it doesn't stand up to abrasives as well.

Which is better, depends on the application. Go to www.graphalloy.com/html/inquiry.html and give the engineering department a chance to review your application.

Can you give an example of a high temperature use?

2008-02-10T08:12:00.001-05:00

GRAPHALLOY has recently been used in a high temperature steam (up to 540C) and inert atmosphere environment to convert wood chips and used cooking oils into biodiesel fuel. Because standard bearings were not an option in this environment, Graphalloy provided a solution. The production of biodiesel fuel is important because it is biodegradable, nontoxic, clean-burning and renewable.

Additionally, it burns much cleaner than petroleum-based diesel, creating about 60% less net carbon dioxide emissions. These factors make it an ideal fuel for buses, trucks and farm equipment. This application design uses several standard bushings as well as custom-sized bushings for their prototype machines.

Graphalloy’s diverse mountings and extensive experience proved valuable in developing a solution for this difficult environment. Alternative fuel manufacturing is a growing field due, in part, to efforts to reduce dependence on petroleum-based fuels. Graphalloy will continue to be a valuable resource for these high-temperature applications.

Why do GRAPHALLOY bushings have oversize OD and ID dimensions relative to my housing and shaft diameters?

2008-01-27T16:34:00.000-05:00

A. A GRAPHALLOY bushing needs to be retained in its housing via an interference fit. The coefficient of thermal expansion of GRAPHALLOY material grades is low relative to steel and other common housing materials. In order to maintain retention at elevated temperatures, the initial press fit needs to be sufficient to overcome the difference in size change as temperatures rise.

Graphalloy is also quite elastic and the interference between the bushing OD and the housing ID will close up the bushing ID upon installation in the housing. The bushing also needs to have a clearance with the rotating shaft to allow movement.

If the housing and shaft are similar materials and are heated to similar temperatures, the clearance between bushing and shaft will remain nearly constant.

What is GRAPHALLOY and when should I use it?

2007-12-21T14:54:00.000-05:00

GRAPHALLOY(r) is a solid, uniform combination of graphite and metal. Molten metal is impregnated into a graphite substrate under high temperature and pressure. Used as a bushing or wear surface, GRAPHALLOY survives dusty atmospheres, high temperature, submersion and corrosive environments. GRAPHALLOY does not swell, shrink, or cold flow.

Graphalloy is self-lubricating and used in difficult applications when a rolling element bearing would fail. It deposits a graphite layer on the inner race which is not normally removed by high temperatures or submersion in a fluid. It is not normally a competitive replacement for a ball bearing where there are no environmental complications.

Hard carbons for bearings and bushings

2007-12-21T14:38:00.000-05:00

Q. Hard carbon materials are available; will they perform better GRAPHALLOY(r) for bushings?

A. Carbon materials can be made over a wide range of hardnesses - from soft brush materials to nearly ceramic hard mechanical seal face materials. Hard carbons can be much harder than usual shaft materials. These hard carbons can score shafts to the point where the shaft is actually cut.

Bushings, especially those internal in pumps, are intended to be wear parts, absorbing the shocks, rubbing and abrasion of normal use without damaging the shafting. GRAPHALLOY is chosen for pumps to provide non-galling, self-lubricating bearings.

GRAPHALLOY with a moderate hardness is used in most pump applications to ensure that expensive shaft materials will be protected.

OUR PURPOSE

2007-11-03T09:35:00.000-04:00

This blog has been established to provide a direct way for engineers and machinery designers to ask questions about carbon and graphite bearings. The engineering staff at Graphite Metallizing Corp, Graphalloy Division, will post your questions together with their recommendations and answers.

We are also building a FAQ page on our web site, http://www.graphalloy.com/, where we will post the most relevant questions and answers.

So challenge us. Be sure to include your email address so that we can get back to you with questions and recommendations.