Page 266 - Boiler plant and distribution system optimization manual

Steam System Optimization 251

Figure 13.3—Effect of air in steam on heat transfer.

Table 13.4—Annual dollar energy loss cost from an Table 13.5—Uninsulated bare metal heat loss in 80
uninsulated 4-inch valve. degree still air for various steam pressures.

excessive, It should be a matter of concern how-
ever it is a matter of economy to insure that all of
the heat possible is returned to the boiler plant for
additional savings. Table 13.5 shows heat losses
per hour for bare metal temperatures in 80 degree steam supplied as well as being a maintenance
still air. burden.
Instead of relying on a hand operated valve,
Inactive Piping which may not shut tight or be leaking, it is better
Inactive or dead piping must be positively to blank off the unused part of the system or re-
isolated from the steam supply, this is often over- move a section of piping to insure positively that
looked. Inactive steam piping wastes 100% of the this section is not wasting good energy.