🔍 Key Concepts

• Boiler start-up sequence when bringing a boiler on the line with the main steam system already pressurized • The purpose of air cocks, vents, and drains on boilers, superheaters, economizers, and air heaters • What must be removed (air, condensate, or water) from each component before it can safely carry full-pressure steam

💭 Think About

• Think about which component must have all the air and non‑condensable gases removed just before admitting live steam to the main steam line at operating pressure. • Ask yourself: which fitting, if left open when you place the boiler on the line, would cause a dangerous loss of steam instead of just finishing a warm‑up or drainage function? • Consider the normal order: first warm up and drain/vent components at low flow, then which specific item is finally secured when placing the boiler in parallel with the line?

✅ Before You Answer

• Verify which device is used primarily to vent air and non‑condensables from the boiler drum during initial firing and warm‑up. • Confirm which vents or drains are normally left open only during warming and then shut before full line-up with the main steam line. • Be sure you know the difference between continuous drains (that may stay in service) and vents or cocks that must be shut once the boiler is up to pressure.