Boiler house Level controls
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Daily test (or once per shift) 1. With the burner firing, operate the sequencing purge valve on the 1st low alarm chamber to purge through the water connection to the chamber and to empty the chamber to drain. Check that the burner shuts down and that the 1st low alarm lamp and bell operates. 2. Return the sequencing purge valve to 'normal'. The alarm should cancel and the burner refire. 3. With the burner firing repeat the test on the 2nd low alarm chamber. The alarm should 'lockout' and should require manual resetting before the burner will refire. 4. On completion of the test, check that all valves and controls are in their normal operating position and that the water level is correct in the level gauge glass. The boiler should not be left until the person carrying out the test is satisfied it is operating normally. Weekly test The weekly test should be carried out or witnessed by a responsible person who appreciates the hazards involved and has been suitably trained in the safe operation of the boiler and its controls. At no time during the test should the water be lowered to the extent that it disappears from the gauge glass. 1. With the feedpump switched off, allow the water level to fall by evaporation until the burner shuts down at 1st low alarm. 2. Blow down the boiler until the 2nd low alarm sounds and the burner controls go to lockout. 3. Raise the water level to normal, reset the lockout, then continue to raise the water level to the high alarm level. Check that the high alarm sounds. 4. Return all valves and controls to normal and monitor the boiler until satisfied that it is operating normally. Quarterly inspection The Health and Safety Executive recommend from experience that the boiler controls should be serviced at least at quarterly intervals. Where the regular tests are carried out properly in a well run boiler house with good water treatment, it may be that only an annual inspection of the probes etc. is required. This is a matter, however, for the user to decide in liaison with his insurance company inspector in order to determine a sensible inspection programme to suit the individual boiler plant. We recommend a regular inspection as follows: 1. Inspect the probe plugs for moisture. 2. Unscrew the probes and wipe away any dirt from the probe tips. If any hard scale is present it may be an indication of more serious scale formation elsewhere in the boiler. Investigate water treatment. 3. Remove the covers from the sequencing purge valves and inspect the water connections to the boiler. Clean as necessary. 4. Inspect the wiring and controllers for damage. 5. Reassemble, refill the boiler and carry out a full functional check.
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AI-P693-30 EMM Issue 1
LCSR1000 Level Control Systems - Chamber Mounted
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