Steam Boiler Blowdowns: Continuous Blowdown VS Manual Blowdown

Blowdown of steam boilers is very often a highly neglected or abused aspect of routine boiler room maintenance. The purpose of boiler blowdown is to control solids in the boiler water. Blowdown protects boiler surfaces from severe scaling or corrosion problems that can result otherwise.

There are two types of boiler blowdowns: ''continuous'' and ''manual''.

Continuous blowdowns use a calibrated valve and a blowdown tap near the boiler water surface. As the name implies, it continuously takes water from the top of the boiler at a predetermined rate. A continuous blowdown is an optional feature and may not be included on your steam boiler; however, all steam boilers should include a means for manual blowdown as standard equipment.

Manual blowdowns are accomplished through tapings at the bottom of the boiler. These openings allow for the removal of solids that settle at the bottom of the boiler. Manual blowdown is also used to keep water level control devices and cutoffs clean of any solids that would interfere with their operation. All steam boilers require manual blowdown whether or not they are supplied with continuous blowdowns.