Expansion Tanks

Product Image
Expansion Tanks
Expansion Tanks - FrontView
Expansion Tanks - LineDrawing

  • Summary
  • Applications

    Pressure stabilization in water based mechanical systems such as booster installations, boiler systems, and chiller plants

  • Description

    Armstrong Expansion Tanks are designed to reduce tank sizes by up to 80% over standard designs. Expansion tanks use compressed air to maintain system pressures by accepting and expelling the changing volume of water as it heats and cools. Diaphragm or bladder tank designs isolate the expanded water from the pressure controlling air cushion – which is pre-charged at the factory and can be adjusted in the field to meet final system requirements

  • Materials

    Carbon steel (shell), heavy duty Butyl (diaphragm)

  • Performance range

    AET plain steel expansion tanks: 15 to 525 USgpm flow
    AX diaphragm expansion tanks: 8 to 211 USgpm flow
    Type L bladder type expansion tanks: 10 to 1056 USgpm flow

Lowest footprint

  • Space saving design for up to 80% reduced footprint over standard tank designs

Low operating cost and risk

  • Eliminates air ingress and dampens pressure transients (water hammer) for reduced system corrosion and stress, ultimately extending service intervals and overall system life
  • Stabilizes system pressure, maintaining optimum levels of a critical operating parameter
  • Reduces need for chemical treatment



360 Service and Support

Genuine Armstrong Parts Kits

All the parts you need to keep your systems running perfectly.

Find a Part Kit

resources & tools

More Tools

We have a suite of free online support materials and tools. Find the essentials to learn, apply, and maintain Armstrong equipment.

Get started

Contact Us

Contact us

We are happy to help. Discuss your project and product needs with us, check the status of your shipments, or let us save the day in an emergency.

Get in touch