Armstrong Vertical In-Line Pumps

Armstrong offers multiple types of vertical in-line pumps. Vertical in-line pumps eliminate the need for inertia bases, housekeeping pads, and flex connectors while reducing piping requirements. They are easy to install, space-saving, low-maintenance, and reliable yet flexible options for most HVAC systems.

Types of Armstrong Vertical In-Line Pumps

Armstrong 4300 Vertical In-Line Pumps

Armstrong 4300 pumps offer high-efficiency NEMA-premium motors for significant energy consumption and cost reduction. The isolated mechanical seal, with optional sediment filters or separators, extends seal life in contaminated systems. Thanks to the split-coupled design, the mechanical seal can be replaced without disturbing the pump or motor. No lubrication or seal adjustments are required.

Armstrong 4300 Pump Features

• Cast, ductile iron, or bronze casing
• Cast iron or bronze impeller
• Outside balanced or inside single spring mechanical seal
• Up to 28,000 US GPM (1,800 L/s) flow; up to 500 ft (150 m) head
• 300°F (150°C)
• 1 HP to 1250 HP (0.75 kW to 900 kW)
• 1.5" to 20" (40 mm to 500 mm)

Request a Quote for Armstrong 4300 Vertical In-Line Pumps

Armstrong 4300 Vertical In-Line Pumps Brochure

Armstrong 4300 Design Envelope Pumps

Armstrong Design Envelope 4300 pumps are pipe-mounted UL 778 pumping units with integrated intelligent controls for space-saving installation and superior energy performance. They save up to 75% of energy costs over comparable traditional constant speed or variable frequency operated pump installations. In addition, remote services through the internet enhance reliability and sustain optimal performance over the life of pumps. Armstrong Design Envelope 4300 pumps can be independently operated through embedded Sensorless control or in conjunction with a building automation system (BAS).

Integrated intelligent controls eliminate separate mounting of variable frequency drive (VFD) as well as procurement, installation (including wiring), calibration, and upkeep of a differential pressure sensor. In addition, the vertical motor positioning requires up to 60% less floor space than other pump configurations. 4300 Design Envelope pumps are the expertly staggered product line for perfect pump match-up and selection, especially in retrofit situations. Superior energy performance qualifies for significant cost recovery under utility and government rebate programs. Design Envelope selections also frequently recommend a smaller motor or pump, reducing installed cost.

Armstrong Design Envelope 4300 Pump Features

• Ductile iron e-coated casing
• Stainless steel impeller
• Sintered silicon carbide mechanical seal
• On-board Intelligent Variable Speed controls with Sensorless control
• Split-coupling design and outside balanced or inside single spring mechanical seal
• Controls enclosure UL type 12 or UL type 4X for outdoor applications
• 1-10 HP range standard with DEPM motors that reduce losses by more than 20% over NEMA Premium efficiency
• Network capable of remote performance management services
• 25 to 25,000 US GPM (1.5 to 1500 L/s) flow
• 10 to 300 ft (3 to 90 m) head (composite curves available)
• 300°F (150°C)
• 0.33 HP to 10 HP (0.25 kW to 7.5 kW)
• 1" to 20" (25 mm to 500 mm)

Request a Quote for Armstrong Design Envelope 4300 Vertical In-Line Pumps

Armstrong 4360 Vertical In-Line Pumps

Armstrong 4360 vertical in-line pipe-mounted pumps are designed for space-saving installation and long service life. They are ideal for HVAC-system pumping and light industrial/process pumping (water or glycol-based) applications.

Armstrong 4360 Pump Features

• Cast iron or ductile iron casing
• Silicon sintered carbide mechanical seal
• Inside single-spring mechanical seal
• Up to 350 US GPM (22 L/s) flow; up to 200 ft (61 m) head
• Maximum temperature of 225°F (107°C)
• Power range of 0.33 HP to 15 HP (0.25 kW to 11 kW)
• 1.25" to 3" (32 mm to 80 mm)

Request a Quote for Armstrong 4360 Vertical In-Line Pumps

Armstrong 4360 & 4380 Vertical In-Line Pumps Brochure

Armstrong 4380 Vertical In-Line Pumps

Conventional Armstrong 4380 pipe-mounted pumps are designed for space-saving installation and long service life. In addition, the close-coupled vertical in-line design minimizes pipe requirements and related friction losses resulting in higher system efficiency.

Armstrong 4380 Pump Features

• Cast iron or ductile iron casing 
• Silicon sintered carbide mechanical seal
• Cast iron or bronze impeller
• Inside single-spring mechanical seal
• Up to 2,500 US GPM (160 L/s) flow; up to 300 ft (90 m) head
• Maximum temperature of 250°F (121°C)
• Power range of 0.33 HP to 60 HP (0.25 kW to 45 kW)
• 1.5" to 8" (40 mm to 200 mm)

Request a Quote for Armstrong 4380 Vertical In-Line Pumps

Armstrong 4360 & 4380 Vertical In-Line Pumps Brochure

Armstrong 4380 Design Envelope Pumps

Armstrong Design Envelope 4380 pumps are available in multiple configurations and sizes for HVAC-system pumping and control, general purpose pumping, or industrial/process pumping and control (water or glycol-based) applications. They are pipe-mounted UL 778 pumping units with integrated intelligent controls for space-saving installation and superior energy performance. Compared to traditional constant speed or variable frequency operated pump installations, they save up to 75% energy. In addition, remote services through the internet enhance reliability and sustain optimal performance over the life of the pumps.

Armstrong Design Envelope 4380 Pump Features

• Ductile iron e-coated casing
• Stainless steel impeller
• Sintered silicon carbide mechanical seal
• On-board Intelligent Variable Speed controls with Sensorless control
• Controls enclosure UL type 12 or UL type 4X for outdoor applications
• 1-10 HP range standard with DEPM motors that reduce losses by more than 20% over NEMA Premium efficiency
• Network capable of remote performance management services
• 15 to 450 US GPM (1 to 28 L/s) flow
• 10 to 160 ft (3 to 48 m) head (composite curves available)
• Maximum temperature of 250°F (121°C)
• Power range of 0.25 HP to 10 HP (0.19 kW to 7.5kW)
• 1" to 6" (25 mm to 150 mm)

Request a Quote for Armstrong 4380 Vertical In-Line Pumps

Armstrong Design Envelope 4322 Tango Vertical In-Line Pumps

Armstrong Design Envelope 4322 Tango intelligent variable speed pumps are split-coupled and have a horse power range of 1-10 HP for indoor and outdoor applications.

Armstrong 4322 Tango Pump Features

• Two-pump casing for reduced footprint
• Ductile iron e-coated casing
• Stainless steel impeller
• Sintered silicon carbide mechanical seal
• On-board intelligent variable speed controls with Sensorless control
• Split-coupling design and outside balanced or inside single spring mechanical seal
• Controls enclosure UL type 12 or UL type 4X for outdoor applications
• 1-10 HP range standard with DEPM motors that reduce losses by more than 20% over NEMA Premium efficiency
• Network capable for remote performance management services
• High-efficiency NEMA premium motors available
• Up to 900 US GPM (56 L/s) in parallel flow and 160 ft (48 m) head (composite curves available)
• 300°F (150°C)
• 1/3 HP to 10 HP (0.25 kW to 7.5 kW)
• 1" to 3" (25 mm to 80 mm)

Armstrong Design Envelope Tango Vertical In-Line Pumps Brochure

Armstrong Design Envelope 4372 Tango Vertical In-Line Pumps

Armstrong Design Envelope 4372 Tango intelligent variable speed pumps are close-coupled and have a horse power range of 1-10 HP for indoor and outdoor applications.

Armstrong 4372 Tango Pump Features

• Two-pump casing for reduced footprint
• Ductile iron e-coated casing
• Stainless steel impeller
• Sintered silicon carbide mechanical seal
• On-board intelligent variable speed controls with Sensorless control
• Controls enclosure UL type 12 or UL type 4X for outdoor applications
• 1-10 HP range standard with DEPM motors that reduce losses by more than 20% over NEMA Premium efficiency
• Network capable for remote performance management services
• High-efficiency NEMA premium motors available
• Up to 900 US GPM (56 L/s) in parallel flow and 160 ft (48 m) head (composite curves available)
• 250°F (121°C)
• 1/4 HP to 10 HP (0.19 kW to 7.5 kW)
• 1" to 3" (25 mm to 80 mm)

Armstrong Design Envelope Tango Vertical In-Line Pumps Brochure

Armstrong Design Envelope 4312 Twin Vertical In-Line Pumps

Armstrong Design Envelope 4312 twin pumps are split-coupled and integrated up to 40 HP for indoor and outdoor applications. These pipe-mounted two-pump units feature integrated intelligent controls for space-saving installation, superior energy performance, and full redundancy during operation. They save up to 75% in energy over comparable traditional constant speed or variable frequency operated pump installations and are for HVAC-system pumping, general purpose pumping, or industrial/process pumping (water- or glycol-based).

The integrated twin design packs and ships more economically for less packaging waste compared to loose component shipping and assembly.

Armstrong 4312 Twin Pump Features

• Two-pump casing for reduced footprint
• Cast or ductile iron casing
• Cast iron or bronze impeller
• Sintered silicon carbide mechanical seal
• 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
• Up to 1250 US GPM (80 L/s) flow and 250 ft (75 m) head
• 250°F (121°C)
• 1 HP to 40 HP (0.75 kW to 30 kW)
• 2" to 6" (50 mm to 150 mm)

Armstrong Design Envelope Twin Vertical In-Line Pumps Brochure

Armstrong Design Envelope 4392 Twin Vertical In-Line Pumps

Armstrong Design Envelope 4392 twin pumps are close-coupled and integrated up to 7-1/2 HP for indoor and outdoor applications.

Armstrong 4392 Twin Pump Features

• Two-pump casing for reduced footprint
• Cast or ductile iron casing
• Cast iron or bronze impeller
• Sintered silicon carbide mechanical seal
• On-board intelligent variable speed controls with sensorless control
• Controls enclosure UL type 12 or UL type 4X (outdoor applications)
• Available with NEMA premium motors for significant reductions in energy usage
• Up to 1100 US GPM (69 L/s) flow; up to 100 ft head (30 m)
• 250°F (121°C)
• 1 HP to 7-1/2 HP (0.75 kW to 5.5 kW)
• 2" to 6" (50 mm to 150 mm)

Armstrong Design Envelope Twin Vertical In-Line Pumps Brochure

Armstrong Design Envelope 4302 dualARM Vertical In-Line Pumps

Armstrong dualARM pumps feature two vertical in-line pumps in one casing, eliminating a complete set of piping and fittings. These pumps provide stand-by or two pump parallel operation with no loss of single pump efficiency. One pump can be removed for service while the second continues operating. This pump incorporates two 4300 split-coupled pumps in a single casing.

Armstrong 4302 dualARM Pump Features

• Two-pump casing for reduced footprint
• Cast iron or ductile iron casing
• Cast iron or bronze impeller
• Sintered silicon carbide mechanical seal
• On-board intelligent variable speed controls with Sensorless control or Parallel Sensorless control
• Controls enclosure UL type 12 or UL type 4X (outdoor applications)
• NEMA premium motors
• Inside single-spring mechanical seals
• Up to 1250 US GPM flow and 250 ft head (80 L/s, 76 m) 
• 250°F (121°C)
• 1/3 HP to 75 HP (0.25 kW to 55 kW) 
• 1" to 8" (25 mm to 200 mm)

Armstrong Design Envelope 4382 dualARM Vertical In-Line Pumps

For applications larger than 10 HP/7.5kW, use Armstrong 4382 dualARM pumps for the lowest installed cost, lowest life cycle operating cost achieved with Parallel Sensorless technology, and increased serviceability with built-in isolation valves. This pump incorporates two 4380 close-coupled pumps in a single casing.

Armstrong 4382 dualARM Pump Features

• Two-pump casing for reduced footprint
• Cast iron or ductile iron casing
• Cast iron or bronze impeller
• Sintered silicon carbide mechanical seal
• On-board intelligent variable speed controls with Sensorless control or Parallel Sensorless control
• Controls enclosure UL type 12 or UL type 4X (outdoor applications)
• NEMA premium motors
• Inside single-spring mechanical seals
• Up to 1000 US GPM (63 L/s) flow; up to 140 ft (43 m) head
• 250°F (121°C)
• 1/3 HP to 7-1/2 HP (0.25 kW to 5.5 kW)
• 1" to 8" (25 mm to 200 mm)

Armstrong Vertical In-Line Pumps – Retrofit to Design Envelope

A retrofit of an existing constant speed Armstrong vertical in-line pump to a Armstrong Design Envelope vertical in-line pump utilizing the existing casing and replacing all other components. The retrofit does not require pipe changes or even disconnecting the casing so no fewer hours are required for the work and no pressure test is required. There are savings in the product cost as there is no casing. The insulation does not need to be removed and replaced. Relative to the installation of a separate third party drive, there is no additional wiring because wiring is already available to the motor. Superior energy performance qualifies for utility or government rebate programs in many jurisdictions.

Armstrong Vertical In-Line Retrofit Features

• Cast or ductile iron casing
• Bronze impeller
• Sintered silicon carbide mechanical seal
• On-board intelligent variable speed controls with Sensorless control
• Split coupling and outside balanced or inside single spring mechanical seal
• Controls enclosure UL type 12 or UL type 4X (outdoor applications)
• 25-25,000 US GPM (1.5 to 1500 L/S) flow, 10-300 ft (3 to 90m) head  (composite curves available)
• Up to 300°F (150°C)
• 1 HP to 1250 HP (0.75 kW to 900 kW)
• 1-1/2" to 15" (40 mm to 400 mm)

Learn more about Armstrong Vertical In-Line Retrofit to Design Envelope

Armstrong Vertical In-Line Pump Retrofit to Design Envelope Brochure

Armstrong Vertical In-Line Pump Retrofit to Design Envelope FAQs

Armstrong Vertical In-Line Pump Parts

Armstrong offers repair parts for all styles of vertical in-line pumps. Parts include seals, mechanical seal kits, casing gaskets, coupling kits, flush line replacement parts, and more.

Shop All Armstrong Pump Parts

Armstrong Consolidated Vertical In-Line Pump (Design Envelope, IVS & Conventional) Parts List

Armstrong Vertical In-Line Pump Seal Kits

Armstrong Fluid Technology offers pump seal kits and other repair parts to support the installation and maintenance of their products. Pump seal kits are available individually or sometimes as a component of a complete repair kit.

Learn more about Armstrong Pump Seal Kits.

Armstrong Design Envelope Vertical In-Line Pump Seal Change

Performing a seal change on an Armstrong Design Envelope vertical in-line pumps is up to four times faster compared to the competitor's VSC pumps with a third of the steps required.

Armstrong 4300 Vertical In-Line Pump Seal Change

Armstrong Vertical In-Line Pump Curves

A pump performance curve indicates how a pump will perform against specific pressure head and flow rates. A curve is defined for a specific operating speed (RPM) and inlet/outlet diameter.

Some examples of Armstrong vertical in-line pump curves:

Armstrong Design Envelope Pump Manager

Pump Manager is a cloud-based service provides pump analytics and performance insights along with alerts and notifications for Armstrong Design Envelope pumps. The service supports active performance management in HVAC systems and has proven to be valuable for end users and service personnel as they work to optimize HVAC performance. Pump Manager is now available as a mobile app.

Armstrong Design Envelope Rebates

Depending on your location, Armstrong Design Envelope products may qualify for rebates from your utility company. Visit Armstrong's Rebate page for more information.