Improve Pump Reliability in Light Hydrocarbon Service

The unique properties of GRAPHALLOY® bushings and wear rings enable pumps to run-dry and survive upsets and flashing that cause metal-to-metal pumps or plastic wear parts to fail.

These bearings allow closer running clearances which can provide higher pump efficiencies.

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Is GRAPHALLOY A True “Run-Dry” Material?

GRAPHALLOY® is an alloy of carbon graphite and metal. The graphite provides continuous lubrication without the need for grease oil or other forms of lubrication. GRAPHALLOY deposits a thin film of graphite on the shaft to reduce friction and the metal impregnate help to transfer heat from the rubbing surface to the housing. GRAPHALLOY has much higher temperature limits than many thermoplastics available today. Run-Dry transients will not melt the GRAPHALLOY as it may do to other materials. Normally the pumps can be put back in service immediately after dry running transients while plastics usually require replacement.

For more answers to questions about GRAPHALLOY, click here.

Hot, Cold, Wet, Dry...GRAPHALLOY® Bearings Work When Others Fail

GRAPHALLOY^® bearings handle harsh environments, corrosive liquids and temperature extremes with ease.









Hot:  works at high temperatures where oil-based lubricants burn off or oxidize and plastics fail. Operating temperatures to 750ºF (400ºC). Special grades provide reliable service op to 1000°F (535°C) in non-oxidizing atmospheres. Will not gum or seize.

Cold: does not congeal or solidify at low temperatures or cryogenic conditions. Maintains self-lubrication.

Wet:  operates submerged. Will not swell or wash out. Withstands a wide variety of hostile fluids.

Dry: works without lubrication. Survives run dry applications. Eliminates galling or seizing in hot and dry conditions. Will not attract dust.

These bearings, bushings and components are self-lubricating, corrosion-resistant and non-galling. They operate for long periods under a wide variety of conditions, reduce maintenance and provide increased reliability.

GRAPHALLOY delivers simple solutions to troublesome design and maintenance problems.

Graphite Metallizing Celebrates 100 Years of Quality and Service

Graphite Metallizing Corporation of Yonkers, NY celebrates its 100th anniversary of solving tough bearing problems.

The company began in 1913 when two engineers developed a method for putting molten metal into carbon to create a new material called GRAPHALLOY®, a graphite/metal alloy. Over the years, Graphite Metallizing developed additional grades of GRAPHALLOY to address new applications. Today, GRAPHALLOY customers are comprised of major industrial companies around the world who demand the highest level of quality and service.

GRAPHALLOY is a proprietary material that has exceptional mechanical, chemical, and tribological properties. As a result, GRAPHALLOY works where traditional bearing materials often fail. In addition to being self-lubricating, GRAPHALLOY withstands high-temperatures, 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 can be custom-designed for specific application dimensions and tolerances. GRAPHALLOY standard and custom designed products provide lifetime cost savings and significant operating advantages over conventional bushings and bearings.

Eben Walker, General Manager of Graphite Metallizing said: “It’s amazing that even after 100 years and producing over 150 grades of GRAPHALLOY, our customers and our engineers continue to find new applications for this versatile material.”

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.

Fitted Pumps Successfully Run Dry with GRAPHALLOY

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.

How Difficult Can Pumping Water Be?

A paper mill in the Pacific Northwest was experiencing failures with the operation of three identical boiler feed pumps (two motor driven and one steam-turbine driven). The pumps were 6-stage horizontal split, opposed impeller, channel ring diffuser design. Multistage split-case pumps of this design are susceptible to deflection and vibration during start-up, coast down and upsets.

These pumps were operating in 260 degrees F (125 degrees C) boiler feedwater at 3560 RPM. With the instrumentation available, the operators had a difficult time determining where the pumps were operating on the performance curve.

While attempting to bring the steam turbine driven pump online, the pump was run at zero flow until it seized. Because of a history of failures, the OEM repair center recommended that the pumps be refit with GRAPHALLOY stationary wear parts.

Engineers at Graphite Metallizing Corporation designed a retrofit solution modifying the existing metal wear parts to accept GRAPHALLOY inserts. The case wear rings, diaphragm bushing and intermediate cover bushings were all modified to include Nickel GRAPHALLOY wear parts.

Failure Averted

Soon after this conversion, the pump experienced another incident. A minimum by-pass line was plugged and, as a result, the pump operated at no flow until the users were able to discover the plugged line (located two floors above the pumps).

The non-galling, GRAPHALLOY fitted pump not only survived but continued in service. Metal or plastic wear rings would have almost certainly caused a failure. The upgrade to Nickel GRAPHALLOY stationary wear parts allowed these pumps to operate under severely adverse conditions that could cause plastics to melt and metals to seize.

The GRAPHALLOY retrofit provided this paper mill with increased efficiency and reduced downtime.

Consider the advantages of GRAPHALLOY for your next pump application:

• Self-lubricating
• Non-galling
• Engineered for your specific application
• Operates in temperatures from -400 degrees F to +1000 degrees F/-240 degrees C to 535 degrees C

GRAPHALLOY® Solves a Proton Beam Problem

The Fermi National Accelerator Laboratory (Fermilab) is a Department of Energy atomic particle research lab in Batavia, IL. Fermilab specializes in high energy physics research and devotes much of their efforts toward understanding the basic properties of fundamental particles including neutrinos and other subatomic particles.

Fermilab turned to GRAPHALLOY® bearings from Graphite Metallizing Corporation to solve a problem in a critical "neutrino target adjustment" mechanism when previous solutions had failed.

Fermilab's MINOS (Main Injector Neutrino Oscillation Search) is designed to observe neutrino beam composition and energy distribution as it travels underground from Fermilab in Illinois to the Soudan Iron Mine in Minnesota. Neutrinos produced by the particle accelerator at Fermilab are "beamed" 450 miles through the earth.

To produce this beam of neutrinos, a proton beam starts at the Main Injector accelerator. The protons are magnetically focused onto a target. Once the protons strike the target, secondary particles are produced, focused by a pair of magnetic focusing "horns". The particles of interest then decay into neutrinos. It is the mechanical adjustment of these focusing horns that requires GRAPHALLOY bearings.

This operation runs in a particularly hostile environment. It is radioactive and corrosive and is exposed to nitric acid and ionized air. Metallic bushings cannot be used. In addition, polymers, organics, plastics and oil cannot be used in the operation. Finally, the bearings must run dry.

The unique properties of GRAPHALLOY provided the solution to this application. GRAPHALLOY bushings were used to target and position the horns because other materials would corrode and freeze up...and continue to outlast the other materials in this target assembly.

(Image courtesy of Fermilab Visual Media Services)

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.

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

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.

How will Graphalloy handle our jet fuel pump application?

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.