Heating I Section#2 Hot Water Boiler Quiz#4

This study session deals with getting the hot water to the rooms of the house.

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 four problems found with expansion tanks.
• List three problems found with pumps.
• List four problems found with pipes.

In a radiant hot water heating system, the pipes serve two purposes. What are they?

1. Distribute heated water to the rooms
2. Transfer heat to the rooms and return the cooled water to the boiler to be reheated.

List three materials that have been used for distribution piping in hot water systems in the past.

1. galvanized steel

2. black steel

3. copper

List three styles of circulators.

1. Pump and motor are mechanically coupled with bearings that have to be oiled.
2. Pump and motor are close-coupled with permanently lubricated bushings.
3. Pump and motor are close-coupled with water lubrication.

What are the four components in the distribution system for a hot water system?

1. Pump

2. Pipes

3. Radiators, convectors or baseboards

4. Expansion tank

What is the basic difference between an open system and a closed system?

1. The open system operates at atmospheric pressure, the closed system is pressurized.
2. The open system does not have a pump and does not need a pressure relief valve. An open system does not have automatic water make-up (pressure reducing valve).

What is the function of the expansion tank in a closed water system?

The expansion tank allows the water to expand as it is heated, so that excess pressure will not build up in the system.

What is the purpose of the reverse return in a two pipe closed system?

The reverse return serves to make each piping loop similar length. This equalizes heat delivery to each room.

Where is the expansion tank typically, in an open system?

Above the highest level radiator.

Where is the expansion tank, typically, in a closed hot water system?

Expansion tanks in closed systems are typically located near the boiler, often hung from the ceiling.

When a black steel pipe is extended with copper pipe, what can occur?

the pipe may rust at the connection due to galvanic reaction <selected answer>

the circulator may not be able to overcome the pressure change at the junction

the copper pipe will wear through with the friction force of the water

the copper pipe will rust because of the galvanic reaction

nothing occurs when steel and copper piping are joined

Closed systems must have circulators.

False