Christmas layup procedure for your boilers

With many businesses closing for Christmas, Byworth’s Chief Technician, David Tilleard, discusses how to prepare a boiler for short term storage.

David reports: “A boiler left idle for a extended period of time is likely to suffer corrosion as the normally low levels of oxygen scavenger are depleted. Any boiler that’s going to be left for a few days should be ‘laid up’.”

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Wet Layup Procedure

All parts, including any economiser or superheater, should be filled with correctly conditioned water.

Non drainable  superheaters should only be filled with condensate quality water that has been treated with volatile chemicals. Note: it is important that all air is eliminated and there should not be any leakage.

  • Shut boiler down and allow it to cool completely
  • During the cool down period some circulation of boiler water occurs – this is the best time to measure boiler chemistry in order to establish water conditions for lay-up
  • The content of sulphite within the water should be increased to 100 – 200 mg/kg and alkalinity raised to between pH 10 – 11.5 This will ensure the boiler internals are protected against corrosion
  • To ensure proper distribution of the chemicals, the boiler should be filled with a premixed solution or by heating the boiler while it is partially filled
  • The boiler should be completely filled and then sealed.
  • the pH and oxygen scavenger reserve should be checked weekly and additional treatment chemicals added if required to keep within the recommended range.

Before putting the boiler back into service, drain the boiler back to normal working level and re-establish reserves of conditioning chemicals if required. Refer to the manufacturers operating instruction on how to start a boiler from cold.

Dry Layup

If the boiler will be:

• idle for a longer period of time

• or where there is a risk of freezing of the boiler

• or condensation in the flue system is resulting in corrosion

read David’s dry layup procedure or consult Byworth for more instructions on dry layup.