🔍 Key Concepts

• Thermal stress in boiler components when heating from cold conditions • Effect of burner sprayer plate orifice size on heat input and rate of temperature rise • Manufacturer recommendations and typical time frame for gradual warm-up of a cold boiler

💭 Think About

• Which option best protects the boiler metal from rapid temperature changes that could cause cracking or distortion? • How does the size of the sprayer plate orifice affect the initial firing rate and heat intensity on cold boiler surfaces? • Is it more important to strictly meet a short time limit, or to control the rate of heat input during a cold start?

✅ Before You Answer

• Compare how a small vs. large orifice affects flame size, heat input, and metal temperature gradients on a cold boiler • Eliminate any options that imply rushing the warm-up in a way that could cause thermal shock • Think about what procedure would most likely be found in a safe, conservative start‑up checklist for raising steam on a cold boiler