Heating I Section#2 Hot Water Boiler Quiz#2

This study session deals with automatic safety controls.

The estimated completion time for this study session is sixty minutes.

Objectives
At the end of this study session, you should be able to:

• List and describe in one sentence the function of the four types of automatic safety controls.
• List fifteen problems found with automatic safety controls.

List the four safety controls which may be found on all hydronic systems.

1. Pressure-relief valve

2. High-temperature limit (aquastat)

3. Low-water cut out

4. Backflow preventer

What is the purpose of the low water cutout on a large residential boiler?

the low-water cutout prevents boiler damage if the system loses its water for any reason. The cutout prevents the boiler from firing.

Where is the pressure relief valve typically located? Also, where does it typically discharge?

The pressure relief valve is located on top of the boiler, and typically discharges near the floor.

Why do we need a backflow preventer on a modern hydronic system?

To prevent contaminated boiler water from flowing backwards into the domestic water piping (drinking water) if the domestic side loses pressure for any reason.

Are we required to test the pressure relief valve?

No

Is it possible to have a pressure relief valve that is too small for the boiler?

Yes

What is common temperature setting for the high temperature limit switch?

210F

What is the normal operating pressure in a boiler?

12psi to 15psi

What is the normal setting on the pressure relief valve?

30psi

What is the safety control which prevents us from get superheated water in a boiler system?

The pressure relief valve