Page 205 - Root Cause Failure Analysis

Steam Raps 193
Calibration

Steam traps, such as the bimetallic type, must be periodically recalibrated to ensure
proper operation. All steam traps should be adjusted on a regular schedule.

INSTALLATION
Installation of steam traps is relatively straightforward. As long as they are properly
sized, the only installation imperative is that they be plumb. If the trap is tilted or
cocked, the bucket, float, or thermal valve will not operate properly. In addition, a
nonplumb installation may prevent the condensate chamber from fully discharging
accumulated liquids.

OPERATING METHODS
Steam traps are designed for a relatively constant volume, pressure, and condensate
load. Operating practices should attempt to maintain these parameters as much as
possible. Actual operating practices are determined by the process system, rather than
the trap selected for a specific system.

The operator should periodically inspect them to ensure proper operation. Special
attention should be given to the drain line to ensure that the trap is properly seated
when not in the bleed or vent position.

A common failure mode of steam traps is failure of the sealing device (Le., plunger,
disk, or valve) to return to a leak-tight seat when in its normal operating mode. Leak-
age during normal operation may lead to abnormal operating costs or degradation of
the process system. A single V4-in. steam trap that fails to seat properly can increase
operating costs by $40,000 to $50,000 per year. Traps that fail to seat properly or are
constantly in an unloading position should be repaired or replaced as quickly as possi-
ble. Regular inspection and adjustment programs should be included in the standard
operating procedures.