Term
Controls
FLAME SUPERVISION |
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Definition
Thermoelectric
Flame rectification
Vapour Pressure |
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Term
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Definition
Taper plug Valve
Ball Valve
Solenoid |
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Term
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Definition
Permanent Pilot
Electronic/electrical
Hot Surface |
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Term
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Definition
Simple Regulator
Modulating Regulator
Air/Gas Ratio Control Valve |
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Term
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Definition
TTB
Interrupted thermocouple
Vitiation Sensing
Pressure Switch
Hi-Limit stat |
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Term
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Definition
Liquid Expansion Thermostatic Switch
Thermistors
Bi metallic Switch
Rod Type
Wax Capsule |
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Term
FSDs that have a max operating time of
180seconds |
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Definition
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Term
FSDs that have a max operating time of
45 seconds |
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Definition
| Storage water heater 35-70kW |
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Term
FSDs that have a max operating time of
50 seconds |
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Definition
| Storage Water Heater <35kW |
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Term
FSDs that have a max operating time of
60seconds |
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Definition
Central Heating Boilers
Cooker Ovens
DFE
W.A.U 60kW gross
Combi/Multipoint WH |
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Term
FSDs that have a max operating time of
90seconds |
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Definition
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Term
Flame Supervision Devices
Flame Rectification (Ionisation) |
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Definition
Electronic method of FSD,very quick acting.
Principle:
Within a flame there are positively charged particles called IONS
These can conduct an electrical current.
But will only happen when a flame is present. |
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Term
Flame Supervision Devices
Thermo-Electric |
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Definition
Principle:Same as thermocouple.
Small Electromagnet
spring loaded Main Valve
Interrupter Valve
Thermocouple |
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Term
Flame Supervision Devices
Thermo-Electric
"CLICK TEST" |
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Definition
1.With MAIN BURNER operating
2.Isolate the gas supply at A.I.V
3.Check time taken for thermoelectric,magnetic valve to close.
4.After close of valve,Restore gas supply at A.I.V
5.Check there is no gas at the burner before relighting the appliance |
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Term
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Definition
Used to control throughput of gas fires n cookers
Consist of taper plug held in position by compression spring. |
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Term
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Definition
Commonly used for isolating appliances, and as ECVs.
Maintainance free ,cannot be repaired |
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Term
Flow Controls
Fire pedestal elbow |
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Definition
Consists of
Washer or O ring,attached to disc,which is then driven onto a seat by means of a screw thread or spring. |
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Term
Flow Controls
Self sealing valves |
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Definition
(Bayonet plug in sockets)
Used in conjunction with flexible gas pipes for cookers. |
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Term
Flow Controls
Solenoid Valves |
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Definition
Electrically controlled gas valve,normally constructed so as to be normally closed.
"copper wire on a bobbin"
purpose is to turn on or off a gas supply by electrical means. |
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Term
Flow Controls
Taper Plug Valves |
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Definition
Normally consists of tapered brass or aluminium plug.
Valve is operated manually by means of a handle |
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Term
Flow Controls
Cooker Lid Safety Shut-Off Valve(SSOV) |
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Definition
Unique to gas cookers with drop down lids.
If the lid is dropped without the hotplate burners being turned off.
This valve will extinguish the burners |
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Term
Flow Controls
Self Sealing Disc on Seat Valve |
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Definition
AKA Bayonet plug in sockets.
Used with flexible gas pipes.
For Cookers and tumble dryers |
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Term
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Definition
when two dissimilar metals are joined together at one end and heated a small electric current is generated.
When tip of thermocouple is heated by a flame,(normally pilot),this generates small electric current,which is transmitted to control. |
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Term
| Main Purpose of Controls into catagories |
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Definition
Gas Pressure Regulation
Flow Control
Temperature
Flame Supervision
Multifunctional
System Monitoring/safety |
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Term
Temperature Control
Liquid Expansion Thermostatic Switch |
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Definition
Positioned where the temp is to sensed.
1)spring loaded electrical contacts
2)When Contacts separate(due to liquid expansion)current flow stops
3)this switch controls gas flow by switching a solenoid gas valve on and off
4)found on trad CH boilers and combi boilers
5)PHIAL is located within the top of the heat exchanger |
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Term
Temperature Control
Liquid Expansion Thermostatic Valve |
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Definition
Principle:Liquid when heated expands
Liquid contained in a PHIAL
Flexible Metal Bellows
Capillary Tube
Most commonly found on gas cooker ovens |
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Term
Temperature Control
Thermistor |
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Definition
Do not contain any moving parts.
Contain materials which when heated either decrease or increase in electrical resistance.
This can be monitored by a PCB to activate an electrical solenoid to control flow of gas to a burner |
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Term
Temperature Control
Thermo Disc |
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Definition
Contained in a plastic housing,ativated by a bi-metallic disc.
Disc will flex at predetermined temp
Used on ch boilers,W.A.U and tumble dryers |
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Term
Temperature Control
Thermostatic valves and switches |
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Definition
Purpose is to automatically maintain or limit the temp of a given situation.
eg air temp,water temp etc |
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Term
| Which is the most common type of flame supervision device is fitted to domestic cooker ovens? |
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Definition
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