Unit 22 - Chapter 99 Flashcards
An air separator should always be installed in
A horizontal pipe
Diverted fittings are used in the supply lines to heating units
When a higher heating output is required from the unit or when the distance from the unit to the supply is far
The air removed by the air separator is vented to the
Expansion tank
Flow control valves are necessary in each circuit in the multi zone pump system
To prevent continued circulation of hot water after the circulator has been stopped by the zone control
To ensure that each zone circuit (of a multi zone system) has the proper flow of water to provide the required heat a
Balancing valve is used
Excessive pressure build up due to a rise in temperature and the resulting expansion of the water in the system is prevented by the use of
An expansion tank
To prevent corrosion in the expansion tank it is sometimes filled with
Nitrogen
The temperature control on a steam to hot water converter controls
The steam control valve
The expansion tank in normally attached to the
Boiler or hot water supply line near the boiler
Improper location of the circulating pump and expansion tank can cause
- the circulating pump to cavitate
- some points in the system to be under negative pressure
- air to be drawn into the system
- vapour bubbles to form in the circulating pump
The minimum reading on an altitude gage from the top of the boiler to the highest point in the system plus
1.2 m (equivalent to 12 kPa)
The purpose of a pressure reducing valve is to
Automatically reduce pressure and maintain it
What type of boiler would you expect to find in a hot water systems incorporating a converter?
A steam boiler
For hot water heating systems in small buildings, the minimum operating pressure should be
83 kPa
Which of the following chemicals are used for cleaning in hot water systems?
- soda ash
- sodium hydroxide
- Trisodium phosphate
NOT weak acid solution
