What conditions must be met regarding uptake dampers and air register doors while fires are lit in a boiler?

When operating a boiler with fires lit, it is crucial for safety and efficiency that the uptake dampers are locked open. This requirement helps to ensure that exhaust gases produced by combustion are effectively routed away from the boiler and do not accumulate within the boiler space. Keeping the uptake dampers locked open also aids in maintaining proper combustion air flow and prevents the risk of backdrafting, which can lead to dangerous situations such as explosions or excessive pressure build-up.

In terms of boiler operation, locking the uptake dampers open promotes the safe and efficient release of flue gases to the atmosphere, while also improving combustion efficiency by ensuring that there is sufficient draught. This supports optimal flame stability and helps maintain appropriate temperatures within the boiler.

While other conditions regarding air registers and dampers may be relevant under different operational circumstances, the specific requirement to have the uptake dampers locked open during active firing of the boiler is fundamental to safe operations.