8.3 Water level controls and limiters The testing regime for water level controls needs to be specific to the type of equipment employed. As a minimum it shall verify the functionality of the water level controls and the associated alarms & limiters. This shall form part of the operating instructions for the boiler system. The following need to be considered when drawing up instructions: x The manufacturer’s recommended test methods must be carried out as a minimum; x Any departure from the test frequencies outlined in the arrangements must be supported by the risk assessment; x Only a competent boiler operator shall carry out the tests; x At no time during a test shall the water be lowered to the extent that it disappears from the gauge glass; x If a boiler fails a functional test of the level limiting devices it must be shut down and not brought back into service until such time as the fault has been repaired and the level limiting devices successfully re-tested; x Test results shall be logged (either electronically or manually) with boiler operator’s name, date of test plus any corrective action taken; x Corrective action following alarms shall always be taken by the competent boiler operator; x After tests have been completed, ensure that the water level is restored and that all valves are in the correct operating position. The boiler shall not be left until it is operating correctly. Further details of tests can be found in BS EN 12953 Part 6 Annex C. While the recommended tests are useful for all boilers, the recommended frequency is only appropriate to boilers designed to this standard; risk assessment may demonstrate that some tests should be carried out more frequently. As a minimum, the level limiters shall be proven by test on a weekly basis unless risk assessment demonstrates otherwise. It is unlikely that a lower frequency will be suitable for a boiler that does not possess systems for limiting the water level in accordance with the relevant parts of EN 12953. It is strongly recommended that gauge glasses on steam boilers are always left open to the boiler during normal operation and the connections to the gauge glasses must be fitted with auto shut off devices for safety of boiler operatives. 8.4 Burners and combustion tests Combustion equipment must comply with the relevant standards (see Appendix 1, References). Maintenance and testing by a qualified person in accordance with manufacturer’s instructions is essential to ensure safe and efficient operation. Manufacturer's instructions for the operation of burners shall contain such information as is required for a boiler operator to use and test the equipment supplied. Access to burner controls and safety related devices which are to be tested by operators shall not be obstructed by fixed panels or otherwise obscured. Combustion tests shall also be carried out as appropriate to the type of system in operation. Certain tests, such as visual flame examination or furnace inspection may not be possible or practicable on some designs of boiler, so use of an alternative test such as a CO, CO 2 or O 2 may be appropriate.
BG01 Guidance on the safe Operation of Steam Boilers Edition 2 – © 2019
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