Procedures followed during the maintenance of water tube boilers

Procedures followed during the maintenance of water tube boilers :

• Remove the air register (s), clean thoroughly and check for proper operation.

• Diffusers and burner tubes which are prone to get dirty/clogged are cleaned.

• Register-flaps if worn due to their oscillating movements are repaired/renewed.
• Superheater tube compartment is to be thoroughly cleaned of dirt and the tubes must be properly inspected.

• Stiffeners/ supports may be checked and renewed as necessary.
• Water-washing may be carried out provided the refractory is not affected.

• Soot and deposits are cleaned out from the furnace and tube-walls.

• The main tube-bank and fire-row tubes should be examined for damage and cleanliness.
• Sliding feet for the boiler frame is to be checked and greased.

• During commissioning back, the boiler should be checked for steam and gas leakage.

Following are the additional procedures carried out for major overhauls:

• Header tubes and water tubes as accessible through the hand holes should be inspected by an introscope and internal of the steam drum should also be checked.
• Improper boiler fittings should be dismantled, checked, grounded/polished and repacked.
• Soot-blowers are overhauled and refractory damage must be repaired.

• Chemical cleaning may be required in consultation with a specialist if deposits are found in the boiler tubes in spite of water treatment.

• The chemicals in use are usually sodium carbonate (added with sodium phosphate if required and in a proper solution) and anhydrous trisodium phosphate.
• While water-washing, drain connections are to be provided / kept open in the boiler floor.