Year 2 Review Flashcards
What does a storage hwt use to heat liquid?
Heat exchanger
A fresh air inlet is used to with what sanitary arrangement?
Building trap
Lowest fuel input that a burner can run on to keep from flaming out
Low Fire
What type of burner relies on atmospheric conditions to supply all air to burner
Non-me handicap burner
What type of burner uses a fan downstream of combustion zone to draw in air supply for combustion and vent products of combustion with positive vent pressure?
Induced draft burner
What type of burner uses a mech. Supply to supply combustion air at pressure necessary only to overcome the resistance of the burner
Fan assisted
What type of pre-mix burner has become common in redo condensing boilers
Aspirating mixer
Max flame temps for my c3h8 and butane
1980C
What is the purpose of a burner flame retention device
Reduce gas mixture velocity
What are the 3 common types of pilot ignition systems?
Continuous, intermittent, interrupted
Which pilot ignition system uses a thermocouple or similar as a safety
Continuous pilot
Which pilot system uses the pilot while the main burner is going and shuts both off after satisfying demand
Intermittent pilot
Which of the pilot systems extinguishes pilot while main burner runs
Interrupted pilot
Thermocouples are used with what type of pilot
standing pilot
In a flame rectification system what setting should multimeter be set to
microamps dc
How many thermocouples in a thermopile
10-30
How are multiple thermocouples connected in themopile
Series
How long can the thermocouple take to cool down and close off gas valve in the event of a failed ignition?
90 seconds
What should an open circuit test on a thermo couple produce
30mv
What does a closed circuit test show?
Millivolt maintained under load
Thermocouple should be replaced if it cannot produce a closed circuit reading of less than?
9mv
What is the minuimum bend radius of a radiant tubing bend?
10* the od of tubing
How much concrete must be maintained over top of tubing?
3/4”
Minimum spacing for restraints in a bend on a radiant heating loop?
0.2M or 8”
Test for radiant piping? Time/psi
100psi for 30 min
Max spacing between ties on radiant tubing on a straight run
3M 10’
How much larger should a heat plant on a radiant system be that it’s sized for ?
10%
What does pump curve indicate?
Pumps gym capacity given the feet of head needed to overcome
