🔍 Key Concepts

• Trace the steam path from the inlet fitting up through the valve body and into the soot blower element. Note where the labeled pressure control disk is located relative to the nozzle and valve spring. • Think about what happens to steam pressure and velocity as it passes through a restriction or orifice versus what happens when you change the rotation arc of the blower. • Distinguish between parts that control motion (rotation, travel, arc) and parts that control steam conditions (pressure, flow, velocity).

💭 Think About

• Look at which component is in direct contact with the high‑pressure steam just after the inlet. Would a disk in this location more likely affect the blower’s rotation, or the steam characteristics entering the element? • If boiler pressure fluctuates, what device in this assembly would keep the soot blower element from seeing excessive pressure while still allowing effective cleaning? • Which choice describes something that could be done by a fixed disk/plate with a small passage, and which choices describe functions that usually require linkages, cams, or external adjustments?

✅ Before You Answer

• Identify on the illustration whether the pressure control disk is in the steam passage or in the mechanical drive/gear area. • Ask yourself: does the disk appear connected to any gears, levers, or stops that would change the arc of rotation? If not, that helps eliminate some options. • Consider that soot blowers normally need a relatively lower, controlled pressure at the nozzles compared with main boiler pressure; which option matches that role for a pressure control disk?