What factors can cause carryover of boiler water into the steam system?

If the impurities in the boiler feedwater are not dealt with properly, carryover of boiler water into the steam system can occur.

Carryover can be caused by two factors:

1.Priming - This is the ejection of boiler water into the steam take-off and is generally due to one or more of the following:

1) Operating the boiler with too high a water level.

2) Operating the boiler below its design pressure; this increases the volume and the velocity of the steam released from the water surface.

3) Excessive steam demand.

2.Foaming - This is the formation of foam in the space between the water surface and the steam off-take. The greater the amount of foaming, the greater the problems which will be experienced.