Foam Concentrate Tank

An atmospheric storage tank for foam concentrate, used with inline foam inductors and inline balanced pressure proportioning systems.

It carries an expansion dome of not less than 2% of the tank capacity and is kept filled to halfway up the dome. A sediment sump sits at the bottom, with inlet, outlet, drain and fill connections.

The horizontal tank stands on two saddles or legs welded to it and drilled for anchoring, with lifting lugs for lifting it empty. Ends are flat as standard; dished ends are available.

In service

• With AFFF or AR-AFFF, float about 6 mm of good-quality mineral or sealer oil on the concentrate after filling, to limit evaporation.
• Inspect the concentrate periodically to NFPA 11, EN 13565-2 or another relevant standard; with an oil layer, sample with tools that take no oil with the foam.
• Do not use carbon steel pipe, or galvanised pipe, for concentrate.
• Clean any foam spilt on a coated tank straight away with clean water.

Installation

• Lift by the lifting lugs only; set the tank level and anchor it.
• Leave space around the tank, clear of walls and obstructions, where possible.
• Support all connecting pipework independently so no stress falls on the tank.
• Preferably install under a shed; otherwise keep the tank from long periods above 50 °C.