Having a challenging process doesn't have to mean loss of performance or reliability. The Mark 3's additional configurations combine the best Mark 3 ANSI innovations with specialized features to cover most any application. We've highlighted a key feature for each model below, but be sure to download a brochure to see even more features and specifications.

Mark 3 Lo-Flo Pump

The Mark 3 Lo-Flo pump is designed to improve pump reliability and performance in low-flow, high-head applications. The first pump manufacturer to introduce an ANSI standard low flow, high-head pump, Flowserve developed its innovative radial vane impeller and circular, concentric casing to reduce radial loads and shaft vibration while extending bearing and mechanical seal life.

Mark 3 Lo-Flo concentric casing and radial vane impeller

The circular concentric casing is more efficient hydraulically at lower flow rates and the Mark 3's unique design eliminates potential leaks and balances pressures. The Mark 3 Lo-Flo also includes:

  • Flows to 50 m3/h (220 gpm) and heads to 300 m (1000 ft)

  • SealSentry Seals Chambers with advanced self-flushing capabilities

  • External Micrometer Impeller Adjustment that accurately sets impeller clearance in 20 seconds, in the shop or in the field
  • Choice of Standard Mark 3A power end or ANSI 3A™ with 3-year performance guarantee

Mark 3 Unitized Self-Priming Pump

The Mark 3 Self-Priming pump costs less to buy, install and maintain than submersible pumps. Engineered to prime the pump by drawing from liquid sources below ground level or from sources that otherwise lack enough pressure, the Mark 3 can be easily installed at ground level where maintenance is more simply and economically performed.

The Mark 3 uses liquid recirculation to self-prime the pump. The pressure differential between the aerated liquid at the impeller and the nonaerated liquid in the priming chamber creates a vacuum that pulls liquid up the pipe. As a result, the Mark 3 Self-Primer is ideal for suction lift applications or pumping liquids with entrained air or gases.

The Mark 3 Self-Primer uses liquid recirculation to prime the pump

Other performance and reliability enhancements include:

  • Unitized Casing features a large priming chamber, air separator and volute in one integral component, eliminating the need for a separate priming tank

  • Standard Reverse Vane Impeller offers repeatable pump performance throughout the life of the pump
  • SealSentry Seals Chambers with advanced self-flushing capabilities

  • External Micrometer Impeller Adjustment that accurately sets impeller clearance in 20 seconds, in the shop or in the field
  • Choice of Standard Mark 3A power end or ANSI 3A™ with 3-year performance guarantee

Mark 3 Sealmatic Pump

Sealmatic pump's dynamic sealing technology


With the Mark 3 Sealmatic pump, no mechanical seal is needed during operation. A dynamically sealing repeller (expeller) expels fluid from the seal chamber, making it ideal for hard to seal applications. This also eliminates the need for external flushing and process contamination control. Additional features include:

  • Dynamically sealing spinning expeller created centrifugal force to expel liquid from the seal chamber, making it ideal for tough sealing applications

  • Static sealing options prevent leaking when the pump is stopped. Choices include flexible graphite packing, dry-running end-face seals, and stationary fluoropolymer disk seals.

  • Standard Reverse Vane Impeller for repeatable pump performance throughout the life of the pump

  • External Micrometer Impeller Adjustment that allows accurate, easy and rapid impeller clearance setting

Mark 3 Recessed Impeller Pump

Combining the best design features of the Mark 3 ANSI Standard pump with the vortex action of a recessed impeller and thick wall wet-end components, the Mark 3 Recessed Impeller pump delivers extended service life when handling solid, stringy or fibrous slurries.

Mark 3 Recessed Impeller pump features vortex pumping action

The Mark 3 Recessed Impeller pump comes standard with an open impeller design with pump-out vanes that expel solids from critical seal areas and protect solids integrity, ensuring low, positive seal chamber pressure, peak energy efficiency and low NPSHR. The vortex pumping action created by the spinning impeller minimizes abrasive wear because only a fraction (20%) of the media contacts the impeller. Other stand-out features include:

  • Cylindrical volute casing with tangential discharge minimizes turbulence and decreases abrasion, improving pump performance

  • Duplex Stainless Steel Construction is standard, and also available in all standard Mark 3 alloys

  • SealSentry Seal Chambers provide advanced self-flushing, extending seal life
  • Choice of Standard Mark 3A power end or ANSI 3A™ with 3-year performance guarantee

Mark 3 pump literature

Specification Tools

Watch how the Durco Mark 3's exclusive design features to maximize uptime, streamline maintenance and deliver the highest performance for your lowest total cost of ownership.

Solve for tomorrow's challenges today.

If your goal is to improve reliability, Mark 3 ANSI pumps are an excellent start. From upgrading a single pump to standardizing your entire install base, the PP&S team can help you determine your most reliable and cost effective solution – now and for the long run.  We also offer proactive Reliability and TLC Solutions to reduce your total cost of ownership – from one pump, to multiple systems and plant locations.

Give us a call – we'll make maximizing performance while attaining your lowest total cost of ownership not only achievable, but easier.

Click to visit these spotlights on the Durco Mark 3's advanced design features + options:

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RELIABILITY CENTERS
Charlotte NC*: 800.275.4786
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PP&S provides Rotating/Process Equipment and Total Lowest Cost solutions in Alabama, Georgia, North Carolina, South Carolina, Virginia and the Florida panhandle. If you are seeking equipment or support outside these areas or in the EU, please refer to the OEMs' website for distributors in your area.