Fire Protection


Bladder Expansion Tanks (BET)

A Bladder Expansion Tank (also referred to as Thermal Expansion Tank, Glycol Tank, or Sprinkler Tank) is designed with a gas-filled bladder inside to act as a shock absorber to liquid expanding within a building’s fire closed loop sprinkler system.

Systems that utilize backflow preventors can suffer from over-pressure when temperature variation (excessive heat or cold) causes the antifreeze within the building’s fire sprinkler lines to expand resulting in sprinkler system damage. This over-pressurization can be alleviated with a Young Engineering UL Listed bladder expansion tank which “absorbs” the expanding fluid, thereby controlling the pressure to a safe level. When the fluid contracts due to temperature cooling, the bladder expansion tank expels the fluid back into the system. (For a visual explanation, view our bladder expansion tank movie).

If left unprotected, a building’s sprinkler system can be susceptible to extreme pressure in the pipes, fittings and sprinklers themselves; reducing the useful life of these parts.

The National Fire Protection Association (NFPA 13) requires the use of expansion chambers in antifreeze systems which use backflow preventors.

A Young Engineering UL Listed bladder expansion tank is designed to protect a building’s anti-freeze sprinkler system from the damaging effects of thermal expansion.

All Young Engineering’s products can be designed and manufactured to fit your exacting specifications

Features of Bladder Expansion Tanks (BET)

DSC04374Product Highlights

  • Sizes from 1 gallon to 150 gallons
  • Protects antifreeze sprinkler systems from damaging effects of thermal expansion
  • Industrial quality designs
  • UL Listed and manufactured in accordance with the ASME code Section VIII, Div.1
  • All sizes in stock for fast, on-time deliveries
  • 175 psi design pressure with a 4X safety factor


Article: Expansion Chambers for Fire Protection Systems
(pdf file for download)
Bladder Expansion Tank Movie
Bladder Expansion Tank Brochure
Bladder Expansion Tank Datasheets
Bladder Expansion Tank Distributors