Question

 Which of the following is not mounting of boiler ? 
 

• A. Blow-off cock
• B. Feed check valve
• C. Steam stop valve
• D. Steam strap

Hint:

To easily distinguish between the two: - Mountings = safety and control devices mounted directly on the shell (e.g., safety valves, water level indicators, pressure gauges, blow-off cocks).
- Accessories = efficiency-boosting auxiliary equipment (e.g., superheaters, economizers, air preheaters, steam traps).

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
Boiler components are broadly classified into two categories: "mountings" and "accessories".
- Boiler Mountings: Essential safety and operational fittings mounted directly onto the boiler shell, without which the boiler cannot operate safely.
- Boiler Accessories: Additional components installed to increase the efficiency of the boiler, though they are not strictly required for basic operation.
Detailed Explanation:
Let us evaluate each of the listed options:
- Blow-off cock (A): A mounting used to empty the boiler water or discharge accumulated mud, scale, and sediments from the bottom of the boiler shell.
- Feed check valve (B): A non-return valve mounted on the boiler shell that controls the flow of high-pressure feed water into the boiler and prevents backflow when the pump stops.
- Steam stop valve (C): A mounting used to regulate and control the flow of steam leaving the boiler to the main steam pipe.
- Steam strap (or Steam trap) (D): An auxiliary device installed in steam pipelines to automatically drain condensed water (condensate) and discharge non-condensable gases without allowing live steam to escape.
Because it is a pipeline component used to improve thermal efficiency rather than a safety/operational fitting mounted directly on the boiler shell, it is classified as a steam accessory, not a mounting.

Step 2: Final Answer:
The component that is not a boiler mounting is the steam strap.