Bearings that Excel in Pumping Anhydrous Ammonia

Keeping ammonia pumps running was a problem for fertilizer companies until they installed GRAPHALLOY^® self-lubricating bearings.

A major pump manufacturer was repairing a large number of vertical pumps in Anhydrous Ammonia (NH₃) service. Their customer serves the fertilizer industry and needs the pumps back quickly, especially during the short growing season. The pumps, with bronze bushings installed, were failing due to running dry.

Anhydrous Ammonia is an efficient and widely used nitrogen fertilizer. When used as an agricultural fertilizer, it is compressed into a liquid. When injected into the soil, the liquid ammonia expands into a gas and is readily absorbed in the soil moisture. With a boiling point of -28.01° F at a pressure of one atmosphere, Anhydrous Ammonia requires special equipment and technology to transport, store and apply.

The refrigeration or pressurization system can fail and the pumps can flash, run dry and ultimately fail. The pump manufacturer knew from experience that GRAPHALLOY is one of the most recommended bearing materials found in Anhydrous Ammonia service and typically includes the stuffing box bushing, line shaft bearing and bearings in the bowl assembly.

The manufacturer, working with GRAPHALLOY engineers, replaced the bronze bushings with GRAPHALLOY Babbitt Bearings. GRAPHALLOY has kept the pumps from seizing during dry-run, low-flow, start up and shutdown.

According to the pump manufacturer, the usual service life of Anhydrous Ammonia pumps fitted with GRAPHALLOY bearings is 5 - 7 years. In one instance, the pump manufacturer said the GRAPHALLOY bearings showed no wear after running dry for over 24 hours.

GRAPHALLOY provides reliable, problem-free solutions for the most difficult applications. Contact us to find out what GRAPHALLOY can do for you.

GRAPHALLOY® at Middle East Turbomachinery Show

GRAPHALLOY® will exhibit at the Middle East Turbomachinery Symposium in Doha, Qatar on March 17 - 20, 2013. Visit Booth 317. Click here for more information about GRAPHALLOY.

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.”