Armstrong, Close Coupled, Motor Mounted, Pumps, Series 4270Close coupled, motor mounted pump is available in bronze-fitted and all-bronze construction. All models provide tapped openings for venting, draining, and gauge connections. Featuring heavy duty, permanently lubricated motor bearings, Viton seals as standard, non-ferrous engineered resin impeller, stainless steel faceplate and single spring inside mechanical seal.

Armstrong, Close Coupled, Motor Mounted, Pumps, Series 4270

Design Features

  • Pump Sizes 1-1/4", 1-1/2", 2"

  • Capacity Range (3600 rpm) 130 USgpm

  • Head Range (3600 rpm) 130' hd

  • Maximum Working Pressure 150 psig

  • Maximum Operating Temperature 275°F

Features that ensure performance excellence!


Radially-split volute can be left in the line while servicing the pump, eliminating needless disconnecting of pipes. Tapped openings are provided for venting, draining and gauge connections.


High strength engineered resin impeller reduces axial thrust to a minimum, ensuring smooth performance and long life.


The motor is equipped with heavy-duty, permanently lubricated ball bearings adequately rated to accommodate impeller radial loads and residual hydraulic thrusts. Designed to operate at 3600 rpm. (1800 rpm Optional)

Mechanical Seal

Self-lubricating, prevents liquid seepage. A carbon face rotating against a stationary ceramic seat provides positive sealing up to full design pressure. (Type 21)


Aluminum die cast, with integral support foot, delivering lightweight, durable construction.


Motor shaft extends through to impeller, eliminating intermediate bearing bracket for close coupled design.

Back Pull-Out Design

Eliminates the need to break piping connections when servicing the pump. The motor, with bracket and impeller attached, can be easily withdrawn from the volute after moving the volute capscrews.

Series 4270 Product Information
Series 4270 Stock Product Information
Series 4270 I&O Instructions