Deck 12: Expansion Tanks

Question 1

It is good practice to install a pressure-regulator valve near the inlet of any expansion tank.

Answer 1

False

Question 2

Standard expansion tanks typically need to be drained and refilled with air at least once each year.

Answer 2

True

Question 3

Many systems with chronic "air problems" can be corrected by simply rearranging the piping so that the circulator pumps away from the point of no pressure change.

Answer 3

True

Question 4

One inherent problem with standard expansion tanks is that the air and water they contain are in direct contact.

Question 5

When ____ occurs, there is no longer a cushion of air for the system's water to expand against.

A) waterlogging
B) deaeration
C) thermal shutdown
D) hydraulic separation

Question 6

The entire volume of system fluid reaches the maximum fluid temperature simultaneously.

Question 7

In systems that are open to the atmosphere, such as a nonpressurized thermal storage tank, the volume increase of heated fluid is accommodated by an expansion tank.

Question 8

A software module called Expansion Tank Sizer in the Hydronics Design Studio software is an aid for determining tank size and ____.

A) placement
B) pressurization
C) type
D) brand

Question 9

The expansion tank should always be connected to the system near the outlet port of the circulator.

Question 10

It is ____ to install two or more expansion tanks at different locations within a system.

A) standard procedure
B) a manufacturer's recommendation
C) not advisable
D) the user's requirement

Question 11

In a diaphragm-type expansion tank, since the diaphragm separates the fluid from the air, the air ____ the fluid.

A) cools
B) easily combines with
C) is proportional to
D) cannot be reabsorbed by

Question 12

In a typical closed-loop hydronic system, the extra space caused by heated liquid is usually provided by a separate chamber called the expansion tank.This tank contains a volume of ____ that is compressed.

A) air
B) gas
C) water
D) sludge

Question 13

Most modern diaphragm-type tanks use a butyl rubber or EPDM diaphragm.

Question 14

Many of the shortcomings of standard expansion tanks can be avoided by separating the air and water in an expansion tank.

Question 15

A properly sized diaphragm-type expansion tank allows the pressure relief valve to reach a pressure of about ____ psi lower than its rated opening pressure when the system reaches its maximum operating temperature.

A) 1.25
B) 3.33
C) 5.0
D) 6.66

Question 16

The static pressure at the expansion tank connection when the system is filled is based on the height of the system piping above the expansion tank, the type of fluid used, and a customary allowance for ____ psi pressure at the top of the system for proper operation of the air vents.

A) 1.5
B) 3.33
C) 5.0
D) 7.5

Question 17

When ____ circulators are used, the header they connect to should be located close to and just downstream from the point where the expansion tank is connected.

A) multiple zone
B) variable speed
C) hydraulic
D) single zone

Question 18

The air in a standard expansion tank is initially at atmospheric pressure.

Question 19

Expansion tanks have maximum pressure and temperature ratings.This information is stamped on the label of the tank.Typical ratings are ____ psi and 240 F.

A) 5.0
B) 60.0
C) 25.0
D) 86.0

Question 20

The ____ fixes the pressure of the system's fluid at its point of attachment to the piping.This is called the point of no pressure change.

A) circulator
B) heat emitter
C) expansion tank
D) diaphragm