GRAPHALLOY Provides Advantages in Pump Bushings and Wear Rings

GRAPHALLOY^®, a graphite/metal alloy, is used extensively for pump bushings and wear rings.  It offers two key advantages for pumping applications:

1. GRAPHALLOY enables pumps that run dry, flash, or handle extremely low viscosity fluids to survive without damage.  Numerous case histories and pump manufacturer test results confirm that GRAPHALLOY performs where plastics are unable to stand up and metal parts seize disastrously.

2. GRAPHALLOY enables rings and bushings to be designed with tighter clearances which can improve efficiency, increase output, reduce vibration, throttle seal cavities, or act as a seal backup.  GRAPHALLOY is non galling and dimensionally stable and enables pumps to operate at tight fits without the risk of metal-on-metal rubs or seizure.

Click here to learn more about the use of GRAPHALLOY in pumping applications.

GRAPHALLOY Bearings are FDA Accepted

GRAPHALLOY^® bearings are key ingredients for minimal maintenance and uninterrupted production in food contact equipment. The FDA has accepted GRAPHALLOY, a graphite/metal alloy, for use in ovens, conveyors, pumps and mixers.

• Self-lubricating; works without external lubrication
• Operate in extreme temperatures (-450° F to +750° F/-240° C to +400° C)
• Avoid loss of lubricant in steam/pressure washes
• Contain no oil or grease
• Can be immersed in liquids without contaminating food production
• Operate submerged in low viscosity and corrosive liquids

High heat applications challenge the life and durability of conventional bearings. In cold, wet environments, bearings often cannot hold lubrication. Use of GRAPHALLOY bearings can solve these problems and, as a result, reduce downtime and lost production.

For more information about the success of GRAPHALLOY in food applications, please read our Pizza Oven Case History and our Seafood Processing Plant Case History.

GRAPHALLOY Replaces Ball Bearings In High Temperature Application

GRAPHALLOY® self-lubricating bearings keep the wheels rolling for a manufacturer of specialty powders

When a major manufacturer of alumina powders contacted us because of a high rate of sealed ball bearing failures in their oven carts, we knew GRAPHALLOY bearings would solve the problem.

Sudden stops ruin equipment and material

Our customer manufactures high purity alumina powders and specialty powders designed for a wide range of markets including lighting, watches & jewelry, health & medicine, plasma TV and microelectronics. The manufacturing process for the powders consists of loading pans of  powder mixture onto a train of carts which are then driven by an electric motor through a series of ovens. Each cart has four casters, with bushings, that ride on rails into the ovens. It is critical that the carts move through the heating process in a smooth manner, at a constant speed so that the blocks of powder do not break.

The sealed ball bearings on the carts were losing lubrication and sticking due to the high oven temperatures. This was causing the wheels to lock and the carts to come to a sudden stop. The electric motor would continue trying to drag the carts through the oven.  As a result, the powder blocks would break and the cart wheels developed flat spots from sliding rather than spinning.  Since the carts would not move freely, the electric motor would overload and fail.  The carts would then have to be manually pulled through the ovens.

Greaseless GRAPHALLOY Solution
Our engineers reviewed the application and recommended one of our self-lubricating GRAPHALLOY grades to replace the sealed ball bearings. Our customer tested the GRAPHALLOY bearings on two carts. During the test, the customer told us they randomly pushed carts by hand and only two carts moved smoothly when pushed: the carts with the GRAPHALLOY bearings installed. Since the customer changed all his cart bearings to GRAPHALLOY, he estimates saving thousands of dollars annually in replacement parts, maintenance costs, product waste and downtime.

Consider the advantages of GRAPHALLOY for your next application:
- Self-lubricating
- Temperature extremes
  (-400° F to +1000° F/-240° C to 535° C)
- Extended operation
- No downtime

High Temperature Damper Solutions

A power company in North Carolina was having problems with their ID fan dampers between the electrostatic precipitator and the stack.  The high temperature for the flue gas (approximately 300° F) coming out of the precipitator was baking the grease in the bearing. 

This gas contained some fly ash that was causing clutch failures in the damper actuation system and required emergency maintenance to avoid shut down of the boiler. GRAPHALLOY^® 845 inserts were installed to replace the ball bearings. 

The dampers have run trouble free for more than two years.

GRAPHALLOY Solves Problems in High Temperature Steel Mill Cooling Bed

A Midwestern steel mill was using GRAPHALLOY® bushings for the horizontal rollers in their cooling beds. The bushings were thriving under severe heat and water spray conditions. 

Because of this success, the mill was considering using GRAPHALLOY flange bearings for another application: the vertical guide rollers along the sides of the cooling beds that were used to keep the hot steel from running off the sides. 

These guide rollers remain static until a piece of hot steel slams up against them. At this moment, 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. GRAPHALLOY proved to be successful on the vertical rollers as well and the mill has since retro-fitted additional lines with GRAPHALLOY.

GRAPHALLOY at the Houston Pump Symposium

Graphite Metallizing Corporation, manufacturer of GRAPHALLOY® bearings and bushings, will be exhibiting at the 28th Annual Pump Users Symposium in Houston, TX. This symposium will be held at the George R. Brown Convention Center from Monday, September 24 through Thursday, September 27.  

Engineers from Graphite Metallizing will be available to discuss the success of GRAPHALLOY, a graphite/metal alloy, in difficult pump applications. GRAPHALLOY® self-lubricating wear parts keep pumps from seizing during dry-run, low-flow, start-up, slow roll and shutdown. These are conditions that cause metal to metal pumps or plastic wear parts to fail, sometimes catastrophically.

GRAPHALLOY® wear rings and bushings operate at longer intervals without the need for replacements or maintenance which helps reduce downtime and maintenance expenses. In addition, GRAPHALLOY® operates successfully in temperatures from -400°F to +1000°F (-240°C to 535°C).

If you have an application where service and maintenance tasks are cumbersome or difficult to perform, speak with a GRAPHALLOY® representative at Booth #1715.

GRAPHALLOY® Self-Lubricating Bushings Will Not Seize

The environment in a rubber curing autoclave is 300ºF (150ºC) and has live high pressure steam. The grease-lubricated roller bearings were failing due to high heat and moisture,  causing interruptions in production. When a bearing failed, production was stopped due to the short shelf life of uncured rubber. 

GRAPHALLOY® bushings were installed and, after more than one year, there has been no production interruptions. If replacement is necessary, it can be done during scheduled outages because self-lubricating GRAPHALLOY will not seize the shaft.