Bladder Function

Foam fire suppression requires precise concentrate proportioning typically 1-6% mixing with water. Bladder tanks store concentrate in sealed rubber bladder pressurized by surrounding water. During discharge, water pressure collapses bladder forcing concentrate through proportioner maintaining accurate mix ratio throughout system operation without pumps or external power.

Tank Design

Vertical or horizontal pressure vessels with internal elastomer bladder holding foam concentrate. Water fills annular space between bladder and shell. Inlet connections for pressurizing water and foam refill. Outlet delivers concentrate to proportioning valve. ERGIL sizes tanks based on foam system capacity, discharge rate, and required application time typically 20-60 minutes.

System Operation

Fire water pressure fills tank shell compressing bladder and foam concentrate. Upon activation, proportioning valve draws concentrate from bladder mixing with flowing water at designed ratio. Bladder collapse maintains concentrate delivery until depleted. Simple pressure-driven operation requires no power or controls.

Material Selection

Carbon steel or stainless steel tanks rated for fire water pressure typically 150-300 psig. Rubber bladders compatible with AFFF, FFFP, or protein foam concentrates. Materials resist corrosion from foam chemicals and water. Design per ASME Section VIII or UL/FM standards for fire protection equipment.

Applications

Storage tank foam systems, loading rack fire protection, aircraft hangar foam suppression, LNG facility protection, refinery process area systems, and chemical storage fire suppression. Serves NFPA 11 foam systems requiring reliable concentrate proportioning without external power or controls.

Foam Types

Aqueous film-forming foam for hydrocarbon fires, alcohol-resistant foam for polar solvents, protein foam for tank fires, and synthetic detergent foam. Bladder materials selected for specific concentrate compatibility. Tank capacity sized for required foam concentrate volume typically 50-500 gallons.

Installation Features

Mounted above ground near protected areas. Gravity or pressure supply from fire water system. Manual or automatic activation through deluge valves. Bladder inspection ports enable condition monitoring. Refill connections for concentrate replenishment after discharge.

Performance Benefits

Accurate proportioning without pumps, mixers, or power. Bladder separation prevents foam dilution maintaining concentrate potency. Reliable operation during emergencies when power may fail. Simple proven technology meeting fire code requirements. Minimal maintenance with periodic bladder inspection.

Standards Compliance

Systems per NFPA 11 foam fire suppression, UL/FM approval for listed equipment, API 2030 for refinery applications, and local fire codes. Pressure vessels per ASME or equivalent standards. Complete documentation with hydraulic calculations and foam system design.

ERGIL bladder tanks deliver reliable foam concentrate storage and proportioning ensuring effective fire suppression system performance protecting critical facilities and assets.