Severe water hammer can damage pipes, fittings, and regulating valves. The heat contained in a pound of condensate is negligible when compared with the heat contained in a pound of steam. Condensate in the heat transfer unit takes up space and reduces the unit's capacity. It also forms an insulating film inside the unit, decreasing heat transfer efficiency. In order for the unit to be kept full of steam and operating at maximum efficiency, condensate must be removed promptly.
Air is always present during equipment startup and in boiler feedwater.
This feedwater may contain carbonates that dissolve and release C02. Air is an excellent insulator and can greatly reduce heat transfer efficiency by forming an insulator film on heat transfer surfaces. Under certain conditions, as little as one half of 1 percent by volume of air in steam can reduce heat transfer efficiency by 50 percent. Its pressure also robs steam of its temperature. Carbon dioxide can dissolve in condensate that has cooled below steam temperature and form carbonic acid.