In a forced hot-water heating system, the thermal circulation of water is prevented by _____.
a. using small diameter water return lines
b. using large diameter water return lines
c. isolating the circulating pump
d. placing a check valve in the water return line
Question 2
In a given length of pipe, if the flow rate in gallons per minute (gpm) is doubled, pressure drop _____.
a. stays the same
b. doubles
c. quadruples
d. increases slightly
