Foaming is driven by high dissolved solids, high alkalinity, suspended matter, or oil and organic contamination, which stabilize the bubbles so they do not break. The foam rises into the steam space, gives a false high reading in the gauge glass, and is carried over with the steam. Fixes include more blowdown, antifoam chemicals, and skimming oil off a new or contaminated boiler.
Glass is all froth and you can't find a level, it's foaming, blow it down and check the TDS.
Also heard as
- foam
- frothing
Related terms
Carryover
Boiler water and the solids dissolved in it leaving with the steam instead of staying in the boiler.
Priming
Sudden surges that throw slugs of boiler water out with the steam.
TDS
Total dissolved solids: the concentration of dissolved minerals and salts in boiler water, held in range by blowdown.
Blowdown
Draining some boiler water on purpose to remove concentrated dissolved solids and settled sludge.