gas controls

Question 1

How does a safety shut off valve work?

Answer 1

A spring loaded mechanism shuts off the gas supply to the gas tap if the lid closes downwards on a gas hob

Question 2

How does a Gas tap work?

Answer 2

A handle controls a barrel with different sized slots to allow more or less gas through

Question 3

How does a thermo-electric valve work?

Answer 3

The tip when heated by a flame generates a small current and voltage (15-30mV) to hold open a spring loaded gas valve

Question 4

How does a solenoid work?

Answer 4

Electricity flows through a coil of wire creating a magnetic field which can be used to open or close the gas valve

Question 5

How does a low pressure governor work?

Answer 5

Spring loaded diaphragm restricting flow at a certain pressure

Question 6

How does a liquid expansion thermostat work?

Answer 6

Relies on the expansion of a liquid or vapour to open or shut the gas valve

Question 7

How does a liquid expansion (electrical thermostat) work ?

Answer 7

Temperature sensing device that controls a microswitch to a solenoid vale that controls gas flow to the burner

Question 8

How does a liquid expansion FSD work?

Answer 8

Phial is placed in flame to detect heat. If the flame is no longer present the FSD will cut off the gas supply and prevent unburnt gas from escaping.

Question 9

How does a multifunctional valve work?

Answer 9

Combines several components all in one block

Question 10

How does a interrupted thermoelectric valve work?

Answer 10

The user manually opens the spring-loaded valve until the thermocouple creates a current that will energize the magnet within the thermoelectric valve. It also contains a overheat thermostat.

Question 11

How does a thermocouple work?

Answer 11

It’s made of two dissimilar metals, that when heated, will create a small current. This energises the magnet opening the thermo-electric valve.

Question 12

How does a liquid expansion anti spillage device?

Answer 12

Liquid expansion phial contains a microswitch to the solenoid which cuts out gas flow in case of flue reversal spillage. (Back boiler)

Question 13

How does a vitiation sensing device work?

Answer 13

Senses the CO2 level in the combustion air to the pilot burner. If this reaches 1.5-2% or 100PPM it will shut down the appliance

Question 14

How does a zero governor work?

Answer 14

gas pressure it reduced to atmospheric pressure. Negative pressure at the outlet side causes the correct amount of gas to mix with air to achieve complete combustion

Question 15

What is an air pressure switch?

Answer 15

Senses if the fan is working or not based on the air pressure