The Firex Bladder Tank is one component in a balance pressure foam proportioning system. It requires no external power, other than the water pressure to ensure correct operation. The vertical and Horizontal Bladder tanks are designed and constructed in accordance with the latest revisions to ASME code, Section VII for unfired pressure vessels with a working pressure of 175 psi and tested to one and one half times this pressure. FIREX Bladder Tanks are a steel pressure vessel, which stores foam concentrate contained within an elastomeric bladder. The concentrate is discharged from the tank by incoming water applying pressure to the bladder. This applied pressure is transferred to the foam concentrate, supplying pressurized foam concentrate to the proportional.