Meet strict operator demands in the oilfield and the refinery.
by Gary L. Israel
April 1, 2013
  • Changes in ambient temperatures and other weather conditions, such as humidity
  • Line shock from piping that is not anchored properly
  • Piping systems that have sharp bends instead of gentle curves
  • Changes in the product type being pumped
  • Changes in product viscosity
  • High volume (unloading a 50,000-gallon tanker) at high flow rates (4,000 gallons per minute)
  • Changes in product velocity and force
  • Changes in head pressure

The Solution
Faced with the specific challenges in saltwater-handling and refinery applications that are ever-present in oil and natural gas production and refinement, companies are discovering the benefits of centrifugal-style pumps. ANSI centrifugal pumps are ideal for these operations because they are robust enough to pump thousands of gallons of produced saltwater into trucks or pipelines for disposal or reuse. They also have the ability to handle the high-volume/high-flow operations at a refinery.

ANSI centrifugal pumps are engineered for operational flexibility, efficiency and durability. They have two times the wear area between the case and impeller when compared to closed-impeller designs, which optimizes the performance of the pump’s open impeller. The open-impeller design also minimizes concentrated wear by balancing the hydraulic axial thrust load and reducing the stuffing-box pressure. This maximizes pump performance and simplifies maintenance, which can extend pump life and reduce repair costs.

The pump’s casing can be constructed of various materials, including ductile iron; CDM4Cu; alloy 20; and stainless steel, which should be the metal of choice in applications in which the produced saltwater has a high level of H2S. Some ANSI centrifugal pumps are constructed through an investment and no-bake casting process that ensures smooth, precise finishes and consistent, reliable performance. Employing metallurgists is important to strictly supervise all heat-treating operations for maximum durability for all alloys.

A variety of mechanical-seal options will allow the pumps to operate in temperatures up to 500 F (260 C). Other standard-setting features are self-tightening impellers that reduce leaks and failures, the ability to externally adjust the clearance so that peak efficiency is maintained (even after wear-area loss) and standard enhanced power frames.

With a routine regime of preventive and protective maintenance, ANSI centrifugal pumps will consistently operate at their full capabilities. This quarterly maintenance routine should include the monitoring of bearings and lubricants, shaft seals, pump vibration and changes in discharge pressures. These maintenance checks should be performed more often if the pump is used in severe-service conditions, such as those commonly found in oil and natural gas field operations and refining activities.

ANSI centrifugal pumps possess the operational capabilities necessary to meet the demands of high-volume/high-flow, liquid-transfer activities that are prevalent at refineries.

Conclusion
It is ironic that a natural resource that took thousands of years of languishing many miles beneath the Earth’s surface to transform into a usable energy commodity is now being extracted at what seems like the speed of light. In a textbook example of “time is money,” the strength of the modern-day oil and natural gas industry relies on all types of equipment to be readily available—and then perform reliably.   P&S

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