Boilers represent large capital expenditures. Their operational reliability and availability are often critical to facility profitability. Therefore, training and developing personnel responsible for this equipment is essential. Failure to follow a few well-established practices can result in catastrophe. The most common causes of catastrophic boiler failure include: fuel explosion, low water incident, poor water treatment, contaminated feedwater, improper blowdown techniques, improper warm-up, impact damage to tubes, severe overfiring, improper storage, and pulling a vacuum.