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Design Envelope 4312 Twin Pumps

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Design Envelope 4312 Isometric View
Design Envelope 312 Front

  • Summary
  • Applications

    HVAC-system pumping; general purpose pumping; industrial/process pumping (water or glycol based)
    Armstrong Design Envelope Pumps with integrated controllers are OSHPD pre-approved!

  • Description

    Pipe-mounted 2-pump unit with integrated intelligent controls for space-saving installation, superior energy performance, and full redundancy during operation. Saves up to 75% in energy over comparable traditional constant speed or variable frequency operated pump installations.

  • Materials
    • Cast or ductile iron casing
    • Cast iron or bronze impeller
    • Sintered silicon carbide mechanical seal
  • Configuration

    On-board Intelligent Variable Speed controls with Sensorless control. Controls enclosure UL type 12 or UL type 4X (outdoor applications). High-efficiency NEMA premium motors available. Inside single-spring mechanical seals.

  • Performance range

    Up to 1250 USgpm (80 L/s) flow and 250 ft (75 m) head 

  • Temperature

    250oF (121oC)

  • Power Range

    1 hp to 40 hp (0.75 kW to 30 kW)

  • Size

    2" to 6” (50 mm to 150 mm)

Lowest installed cost

  • Vertical In-line design eliminates the need for inertia bases, housekeeping pads, and flex connectors and reduces piping requirement
  • 2-pump casing for reduced footprint
  • Integrated intelligent controls eliminate procurement, installation (incl. wiring), calibration and upkeep of differential pressure sensors
  • Superior energy performance qualifies for significant cost recovery under utility and government rebate programs
Design Envelope

Lowest installed cost. Lowest operating cost.


Lowest operating cost

  • Integrated intelligent controls – combined with perfect component match-up and tuning – for up to 75% in energy savings over traditional constant speed and variable frequency operated pump installations
  • Shorter pipe runs for reduced system friction
  • Vertical In-Line configuration allows less disruptive pump service (casing stays in place)

Lowest environmental cost

  • 75% decrease in energy consumption reduces operational greenhouse gas emissions at equal ratio
  • Elimination of inertia bases, housekeeping pads, flex connectors and superfluous piping avoids all procurement related environmental impacts (material, energy, carbon)
  • Equipment downsizing mitigates environmental impacts associated with procuring unnecessarily large equipment
  • Integrated Twin design packs and ships more economically for less packaging waste compared to loose component shipping and assembly



Lowest project and operating risk

  • Integrated intelligent controls for fast and easy commissioning as well as reduced radio frequency interference/ improved electromagnetic compatibility
  • Single source-responsibility for optimum design and field support
  • Twin design for full redundancy in case of emergency or routine servicing
  • ETL Listed - conforms to UL STD 778
  • Certified to CSA STD C22.2 NO.108
  • OSHPD Special Seismic Certification Pre-approval (OSP) No OSP-0422-10

Case study: Storing food, moving heat

Sainsbury's is saving 30% on heating and cooling costs using a geothermal heat exchange system.

Learn more


U.S.A. Utility Energy Rebate Info.

360 Service and Support

Design Envelope IVS Pumps with Cloud Based Active Performance Management – solution outline

Design Envelope Twin Pumps - solution outline

Design Envelope single-phase power supplement

Armstrong Design Envelope - FAQs

Variable frequency drives and the use of bypasses - fact sheet

Fused Disconnects for use with Design Envelope Pumps - white paper

Design Envelope pump vs. a variable speed drive on the wall - white paper

E-Coating - white paper

Working Clearances of Design Envelope Pump Controls - WhitePaper

Submittals (single-phase)




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