Line D ? Supervisory Systems

Question 1

What is a supervisory system?

Answer 1

A burner control system that requires physical presence of an operator for manual starting of the burner cycle

Question 2

What is the difference between a regular lubricated plug cock and a FM or supervising cock?

Answer 2

The supervising cock incorporates two side outlets which are only open after the main gas passage is completely closed.

Question 3

What is a common name for a manual reset gas shut-off valve?

Answer 3

A Latch valve

Question 4

What prevents the electrically powered manual reset gas shut-off valve from being reset or latched when the valve is not energized?

Answer 4

The handle moves freely and will not engage the internal latch mechanism

Question 5

Referring to Figure 1, before start-up the FM Valve is in the open position to allow gas to the burner. When attempting to open the diaphragm latch valve, why will the valve not engage the latch and open?

Answer 5

The gas pressure is not able to pressurize the diaphragm of the latch valve

Question 6

Referring to Figure 2, after start-up of the burners (FM valves opened), what keeps the solenoid latch valve energized?

Answer 6

Gas pressure to PS1

Question 7

Referring to Figure 3, what must be proven before the burner can be lit?

Answer 7

FM valve closed, gas pressure and air pressure

Question 8

Referring to Figure 3, how does the latch valve stay open when the FM valve is opened to the burner?

Answer 8

The gas bypass and combustion air

Question 9

Referring to Figure 4, what allows the initial engagement of the latch valve before the FM valve is opened?

Answer 9

Air pressure to PS1 and combustion air to the latch valve

Question 10

Referring to Figure 4, what allows the engagement of the latch valve after the FM valve is opened?

Answer 10

Gas pressure to PS2 and combustion air to the latch valve