Ancillary

Main Steam Stop Valve

Isolates and regulates steam flow from boiler to the steam main. Covers gradual opening, warming and water-hammer prevention.

Indian Boiler Course presents this topic in a plant-oriented, examination-ready format. The lesson combines principles, construction, operation, safety, inspection points, troubleshooting and revision questions.

Function

Isolates and regulates steam flow from boiler to the steam main. Covers gradual opening, warming and water-hammer prevention.

Construction and Working

Identify the body, flow path, moving parts, sealing surfaces, actuation method, instrumentation and isolation provisions. Relate each component to the failure it prevents.

Operating Checks

  • Correct line-up and accessibility
  • No leakage, blockage, abnormal vibration or overheating
  • Valid calibration or functional test where applicable
  • Clear identification and documented maintenance history

Common Faults

Typical faults arise from deposits, corrosion, erosion, misalignment, wrong adjustment, instrument failure, sticking, leakage or unsuitable operating conditions.

Exam Questions

  1. State the purpose and explain working.
  2. Draw a labelled sketch.
  3. List failure modes and safety consequences.
  4. Describe testing and inspection.