Chapter 12 - Quiz

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

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

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

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

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

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

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

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

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

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.

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

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

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.

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

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.

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

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.

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.

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