High Expectations in High Temperatures

Modern Pumping Today
September 2013 

Many industrial applications have experienced success with GRAPHALLOY® in high temperatures. A mill reclaiming metals such as titanium feeds metal powders into a drum heated to 1500 degrees Fahrenheit (816 degrees Celsius). The drive shaft spinning the drum is supported by two Graphalloy Pillow Blocks. In addition, GRAPHALLOY Bushings are in the twelve wheels that support the drum as well as the worm gear. This application demonstrates the ability of the bushings to perform in extreme temperatures.

Also, a Midwestern steel mill was using these bushings for the horizontal rollers in their cooling beds. The bushings were thriving under severe heat and water spray conditions. Because of the success with the horizontal rollers, the mill wanted to consider GRAPHALLOY Flange Bearings for another application: the vertical guide rollers along the sides of the cooling beds used to keep the hot steel from running off the sides. Guide rollers remain static until a piece of hot steel slams up against them, at which time they are expected to turn instantly to guide the steel back onto the cooling bed. This mill had been using conventional greased rolling element bearings in the vertical guides that were lasting only a few months. Based on the success with the vertical rollers, the mill has since retro-fitted additional lines with GRAPHALLOY.

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 one hundred 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 has certified two grades of material for use in municipal well pumps and water treatment plant applications.

In some applications, GRAPHALLOY bearings have operated for up to twenty years without maintenance. Standard designs are available but most products are custom designed to the unique requirements of the specific application. ISO 9001:2008 certified as well as NSF/ANSI 61 certified, the company serves a broad range of industries with standard and custom quality bearings, bushings, and related products.

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GRAPHALLOY® Pillow Blocks - The Problem Solvers

Cost-Saving Solutions for Harsh Environments

• GRAPHALLOY^® 845 series flange units have reduced maintenance costs in Chicken Roasters by more than 50% after replacing standard ball bearing units.
• 400°F temperatures caused failure in pillow blocks on a Hot Strip Mill Run Out Table.  GRAPHALLOY 448 pillow blocks were able to withstand the temperature as well as the quench spray.
• Conveyor running above a 1020°F zinc bath presented a problem for traditional bearings. GRAPHALLOY 318 flange units provided years of trouble free operation.
• A vacuum at 1500°F is an environment that most bearings cannot handle. GRAPHALLOY 963 pillow blocks have been running for more than a year without problems.
• Six years of maintenance free operation was the result of the GRAPHALLOY replacements of spherical roller bearing pillow blocks on a salt cake conveyor.
• Fish screens in the Columbia River is a great application for submersible GRAPHALLOY pillow blocks.
• Harsh chemical wash down required replacing 24 of 96 ball bearing pillow blocks on a weekly basis.  GRAPHALLOY 845 pillow blocks have run for more than six years with an annual savings exceeding $20,000.
  
  

GRAPHALLOY^® Pillow Blocks and Flange Units

• Come in FDA accepted grades 
• Impervious to temperature extremes from -400°F to +750°F 
• Withstand wash down and harsh chemical environments 
• Available in split and solid bushings and housings

Pillow Block Assemblies Designed for Long-Life

Pillow Block and Flange Block Assemblies from Graphite Metallizing are equipped with a GRAPHALLOY ^® bushing and are designed for long-life operation. They are easy to install and will operate successfully under a variety of conditions.

Depending on the application, our Pillow Blocks and Flange Blocks are available as in split, solid, solid, self-aligning, cast iron, stainless steel and in a two-bolt or four-blot arrangement.

GRAPHALLOY Pillow Block and Flange Block Assemblies eliminate maintenance and frequent replacements while providing increased reliability.

Visit our website to learn more about GRAPHALLOY Pillow Blocks and Flange Blocks.

GRAPHALLOY® Extends Bearing Life in Paint Drying Oven

A paint drying oven at a brake shoe manufacturer was experiencing two months life from their roller bearings after being exposed to temperatures of 390ºF (200ºC). In spite of the water cooling system in the rollers, the bearing lubrication was failing and causing roller seizure and extensive maintenance costs.  

Self lubricating GRAPHALLOY^® 845 Series Pillow Blocks were installed, eliminating the need for constant lubrication and the need for the water cooling systems. The 845 Pillow Blocks have run for more than a year with no apparent wear. GRAPHALLOY provided a significant improvement in the life of the bearings.

GRAPHALLOY® Solves Power Plant Damper Failure

Pre-heated secondary air makes the inlet-air section of a utility boiler hot...hotter, in fact, than most steel bearings can handle.

A power plant had difficulty operating the dampers that control the flow of preheated air into the combustors. The hot air quickly dried out the lubricant in the steel damper bearings, causing the dampers to seize.

The problem was solved by replacing the steel bearings with self-lubricating GRAPHALLOY^® bearings. These new bearings have been in operation for years without a single failure.

Failing Dampers Hurt Productivity
Secondary air accounts for 85% of the total combustion airflow to the cyclone burners. This air is heated to 650°F - 750° F (350° C - 400° C) by flue gas through a large heat exchanger. It then flows through a windbox duct to the cyclone burners where it is mixed with powdered coal. Airflow to each burner is determined by an 8’ by 6” by 2’ control damper. The dampers are not moved often and the grease quickly carbonized, locking the bearings.

The utility did not want to bring the unit offline for a bearing problem so it tried to make do. The plant was often forced to alter its firing methods.Frequently, the cyclone burners worked inefficiently due to the inability to control the combustion air. In some cases, it was necessary to fabricate a device to forcefully move a damper manually because operators could not budge them.

The Solution

The power plant solved the problem by replacing the lubricated steel bearings with self-lubricating GRAPHALLOY bearings. Of the 40 bearings used in the plant, 30 consist of three sizes of pillow block bearings while the other 10 are four-bolt flange block bearings.

The upgrade was accomplished during a planned outage. Initially, all of the bearings in one boiler unit were replaced. The GRAPHALLOY bearings ran without any problems and, one year later, the plant replaced the bearings in the other boiler.

The Benefits
The power plant experienced the following benefits by switching to GRAPHALLOY

• The cyclone burners now operate more efficiently because the plant can precisely control the flow.
• Operators are now freed from the time-consuming and distracting task of manually 
• The plant has also had a substantial savings in costs for replacement bearings and labor.

Are you experiencing similar problems with heat and bearing failure? If so, the engineers at GRAPHALLOY will work with you to develop the right solution and help you beat the heat.

High Temperatures Pose No Problem for GRAPHALLOY® 845 Inserts

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® Provides Pillow Block Solutions for Confined Areas

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.

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

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.