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WorksheetsNatural Gas Distribution Network Quiz
Total questions: 57
Worksheet time: 29mins
What is the purpose of pressure regulation in a natural gas distribution network?
Close the supply.
Ensure safe delivery.
Prevent gas leaks.
Open the supply.
What is the purpose of a pressure regulator fitted on the inlet to a primary gas meter?
To maintain a defined pressure to a system, by adjusting the flow of gas.
To adjust the pressure so that it meets the needs of the system design.
To maintain and monitor pressure to a system, by cutting off the gas flow in an emergency.
To remove pressure and prevent damage to the system in an emergency.
What is the most likely cause of pressure loss when carrying out a tightness test?
An overrated gas appliance on the system.
The regulator letting by during the test period.
A gas escape somewhere on the system.
The ECV letting by during the test period.
Which statement correctly describes how a dangerous occurrence could happen during the combustion process?
Incomplete combustion due to insufficient oxygen, which results in carbon monoxide.
Incomplete combustion due to excessive oxygen, which results in carbon monoxide.
Incomplete combustion due to insufficient oxygen, which results in carbon dioxide.
Incomplete combustion due to excessive oxygen, which results in carbon dioxide.
How is evidence of incomplete combustion on a gas appliance identified?
A blue flame is present.
The appliance is hot to touch.
Noisy burner when in operation.
Soot deposits around the appliance.
What is the required activation time for a carbon monoxide alarm, when exposed to a concentration of 100 ppm?
Between 10 minutes and 40 minutes
Within 10 minutes
Between 45 minutes and 60 minutes
After 60 minutes
A new hair salon has recently opened. A carbon monoxide detector in the salon is being activated intermittently during business hours. A new room-sealed appliance was recently installed on the premises; a gas-safe engineer has confirmed that the appliance is in good working order. What is the cause of this issue?
Heat produced by electrical panel heaters.
Aerosol products used on hair.
Warm air currents from hair dryers.
Bright lighting used during business hours.
What is a disadvantage of ‘Black-spot’ indicator cards?
They have a short expiry date.
They are not audible.
They are difficult to see.
What type of burner is shown in Figure 1?
Pre aerated burner.
Forced draught burner.
Post aerated burner.
Atmosphere burner.
A customer has noticed a problem with an open flued gas boiler, after having the outside of their property covered with sheet cladding. The flame picture is yellow. Previously, it was blue. What is the cause of this problem?
Heat loss through the external walls when the cladding was installed.
Gas pipework has been obstructed by the cladding, preventing air circulation.
Heat gain through the external walls when the cladding was installed.
Obstruction of ventilation to the outside when the cladding was installed.
According to IGEM/UP/1B, what is the maximum pipe size a domestic gas engineer can install or maintain in domestic premises?
Up to 22 mm
Up to 28 mm
Up to 35 mm
Up to 42 mm
What is the correct method for fluxing an end feed fitting, in preparation for soldering?
Only flux the end of the pipe.
Flux both the fitting and pipe.
Only flux inside the fitting.
Flux the fitting once connected.
What is the requirement for pipes passing through walls with or without cavities?
Must be sleeved with a corrosive-resistant material and sealed at both ends between the sleeve and the wall.
Must be sleeved with a corrosive-resistant material and be slightly shorter than the thickness of the wall.
Must be sleeved with a ferrous metal and not sealed at both ends between the sleeve and the wall.
Must be sleeved with an insulation material and sealed at both ends between the sleeve and the wall.
What is the minimum depth that pipework can be buried below a private garden with no vehicular traffic?
75 mm
200 mm
375 mm
450 mm
What is the allowance for adventitious air through the structure of a property?
25 cm2
30 cm2
35 cm2
40 cm2
A landlord has requested a landlord's certificate for a property. The gas engineer has noticed that an open-flued appliance in a compartment has no ventilation. The landlord has requested that the door to the compartment is not altered. What options should be discussed with the landlord?
The installation is categorised as an At Risk. The boiler must be isolated or ventilation installed directly to outside.
The installation is categorised as an Immediately Dangerous. The boiler must be disconnected or ventilation installed directly to outside.
The installation is categorised as an At Risk. The boiler must be disconnected or ventilation installed directly to outside.
The installation is categorised as Not to current standards. A warning notice must be issued or ventilation installed directly to outside.
What is the ventilation requirement for a single DFE up to 7kw?
50 cm2
100 cm2
150 cm2
200 cm2
What are the requirements for ventilation used for open flued appliances direct to outside?
Must be sleeved, with a fly screen and not closable.
Must not be sleeved, with a fly screen and closable.
Must be sleeved, without a fly screen and not closable.
Must not be sleeved, without a fly screen and closable.
What is the maximum height for an external air vent, from the finished floor level?
150 mm
300 mm
450 mm
600 mm
What notice must be visible on a balanced compartment?
‘The door must be closed at all times’.
‘Do not store towels near the vents’.
‘The door must be open at all times’.
‘Vents must not be obstructed’.
Which statement correctly describes how a U-duct works?
The air inlet and the flue outlet are both at high-level.
The air inlet is at low-level, with the flue outlet at high-level.
The air inlet and flue outlet are both at low-level.
The air inlet is high-level, with the flue outlet at low-level.
What are the working principles of an open-flued appliance?
A flue removes combustion products to the outside. Air for combustion enters the appliance directly from outside.
A flue removes combustion products to the outside. Air for combustion enters the appliance from the room in which it is situated.
It consists of a fan to remove combustion products to the outside. Air for combustion enters the appliance directly from outside.
It consists of a fan to remove combustion products to the outside. Air for combustion enters the appliance via a fan.
How does a Vertex flue operate?
A vertical flue is taken through a roof space to the outside, with its air taken from where the appliance is located.
A horizontal flue is taken through a wall to the outside, with its air taken from where the appliance is located.
A vertical flue is taken through a wall to the outside, with its air taken from outside.
A horizontal flue is taken through a roof space to the outside, with its air taken from outside.
Which factor is most likely to have a negative impact on flue performance?
Flueless heating appliances too close to open-flued appliances.
Openable windows in the vicinity of open-flued appliances.
Over-ventilated areas close to open-flued appliances.
Extraction fans in the vicinity of open-flued appliances.
How should a boiler service be carried out if the manufacturers’ servicing instructions are not present?
Use the flame picture to ensure the pressures are adjusted correctly.
Calculate the output by using the property input requirements.
Refer to the appliance data badge for the correct pressures.
Calculate the input by using the property output requirements.
As part of a service activity, what test is carried out on an open-flued appliance connected to a chimney system?
Flue flow test.
Spillage test.
Integrity test.
Soundness test.
Who is allowed to undertake gas work?
A responsible person with knowledge and understanding and having grandfather rights.
A person holding current and valid gas competency certificates for the specific area of work.
A competent person holding competency certificates and recognised by an approved body.
A person who holds a Gas utilisation qualification issued by an awarding organisation.
Which document refers to the Gas industry's unsafe situation procedures?
IGEM/UP/1A.
IGEM/G/13.
IGEM/UP/1B.
IGEM/G/11.
Which statement correctly describes Regulation 36 (Duties of Landlords) (1) to (12) of the Gas Safety (Installation and Use) Regulations 1998?
Landlords must ensure an annual gas safety check is carried out on relevant gas appliances and their fuels.
Landlords must ensure, when reletting the property, that gas safety checks are carried out on relevant gas appliances and their fuels.
Landlords must inform tenants of the tenants’ responsibility to organise gas safety checks on relevant gas appliances and their fuels.
Landlords must receive confirmation that tenants have organised gas safety checks to be carried out.
An emergency has occurred where a gas appliance has been deemed unsafe. The building tenant refuses to have the appliance capped off and made safe. Which statement describes the correct Unsafe Situations Procedure?
Inform the tenant that Gas Safe will be contacted, and the incident will be recorded on a safety warning notice to be signed by the tenant.
The appliance should be removed. Warning labels and warning notices will be issued.
Inform the tenant that the gas emergency service provider will be contacted, and the incident reported. A reference number must be issued by the ESP.
The appliance should be isolated. Warning labels and warning notices must be issued.
When would the Unsafe Situations Procedure apply?
When homeowners deal with various situations which currently, or may in the future, affect safety.
When safety inspectors deal with various situations which currently, or may in the future, affect safety.
When competent engineers deal with various situations which currently, or may in the future, affect safety.
When building control representatives deal with various situations which currently, or may in the future, affect safety.
Which statement is correct for this situation, according to the Unsafe Situations Procedure?
Categorised as an Immediately Dangerous. With permission from the homeowner, disconnect the appliance, attach a ‘warning do not use’ label, issue a warning and report to RIDDOR.
Categorised as Not to Current Standards. With permission from the homeowner, disconnect the appliance. Attach a ‘warning do not use’ label, issue a warning notice and give advice to the homeowner.
Categorised as an Immediately Dangerous. With permission from the homeowner, disconnect the appliance. Attach a ‘warning do not use’ label and issue a warning notice.
Categorised as an At Risk. With permission from the homeowner, attach a ‘warning do not use’ label and issue a warning notice.
A flueless instantaneous water heater has been installed in a room where the room volume is inadequate. How must this be categorised?
Not to current standards.
At risk.
RIDDOR reportable.
Immediately dangerous.
In a block of flats, where gas meters are housed externally, how would residents turn off the gas to their flats, in order to isolate the gas supply?
Emergency Control Valves (ECV).
Appliance Isolation Valves (AIV).
Meter Inlet Valves (MIV).
Additional Emergency Control Valves (AECV).
An ECV has failed a let-by test. After disconnecting the union on the ECV and confirming let-by using LDF, what is the correct step to take?
Adjust the results of the tightness test.
Reconnect the ECV immediately.
Report the failure to the homeowner.
Contact ESP to Replace the ECV
Which statement correctly describes the requirements for gas meter boxes?
Made of insulated materials to prevent unnecessary heat loss from the property.
Housing is painted in a specific colour, in order to identify the meter operating pressure.
Externally fitted and sealed to prevent a potential gas escape from entering the property.
Housing is located indoors only, to protect against adverse weather conditions.
What action should be taken regarding a gas meter regulator with a broken seal?
Contact the gas transporter to replace the broken seal.
Notify the responsible person, issue a warning notice and fix a label.
A competent engineer must replace the broken seal.
Ask the responsible person’s permission to turn off the gas; issue a warning notice.
Which British standard covers gas meters with a maximum capacity not exceeding 6 m³/h?
BS 5440
BS 5871
When must a tightness test be carried out?
Upon completion of work carried out on a gas installation.
Before and after work has been carried out on a gas installation.
After diagnosing and carrying out repairs on a gas installation.
Before any work is carried out on a gas installation.
What is the maximum installation volume for individual tightness testing in line with IGEM/UP/1B?
Up to 0.025 m³
Up to 0.030 m³
Up to 0.035 m³
Up to 0.040 m³
What are the requirements for purging installations with an IV over 0.02 m³?
Purged to the atmosphere through a fitting.
Purged to the atmosphere through a fire trap.
Purged through a burner with constant ignition.
Purged through an air vent to the outside.
An operative is testing a new installation with appliances and a meter connected. Which statement correctly describes the permissible drop in this situation?
No permissible drop.
2 mb with no smell of gas.
2.5 mb with no smell of gas.
4 mb with no smell of gas.
What should be used when attempting to locate a leak on a gas installation?
Washing up liquid.
Leak detection pellets.
Spray silicone detector.
Leak detection fluid.
What is the most likely cause of pressure loss within a gas installation?
Oversized pipework and bends.
Undersized pipework and elbows.
Modulating gas appliances.
Undersized gas appliances.
The working pressure at the gas meter outlet should be within which range, as stated in IGEM/G/13?
18 mbar to 22 mbar
18.5 mbar to 23 mbar
19 mbar to 23 mbar
21 mbar to 24 mbar
Under IGEM/G/11, what are the requirements where an appliance or system cannot be fully commissioned?
A notice is issued, stating that the appliance or system must not be used.
The gas supply to the appliance or system must be isolated and the fuse removed.
The customer is advised that the appliance or system must not be used.
As part of the tightness test, what are the let-by test requirements?
1-minute let-by test between 5 - 7 mbar
1-minute let-by test between 7 - 10 mbar
2-minute let-by test between 7 - 10 mbar
2-minute let-by test between 13 - 15 mbar
Additional radiators have been installed in a loft conversion. The customer reports that heating levels in the property are not satisfactory since the additional installation was completed. The heat source is a back boiler unit. What is the most likely cause of this issue and how should this be resolved?
The boiler output is not sufficient. The appliance must be range-rated to meet the new demand of the property.
The central heating pipework is too small to accommodate the new flow rates required by the property. The pipework must be replaced.
The water content is higher than the boiler's design capacity. A boiler replacement is needed, to meet the new demand of the property.
The boiler has insufficient ventilation, due to the increase in volume. Additional ventilation must be installed.
What safety control must be incorporated into a cooker hotplate lid?
Safety shut-off valve.
Electric solenoid valve.
Thermal cut-off valve.
Thermoelectric valve.
What must be fitted on a flueless instantaneous water heater that uses a water manifold?
Condensate sensor.
Atmosphere-sensing device.
Pressure relief valve.
Temperature control valve.
What is the action level (CO/CO2 ratio) for a central heating boiler with an air/gas ratio valve?
0.001
0.004
0.008
0.010
How must a flueless appliance be categorised if it has failed an analyser check?
At risk.
Immediately dangerous.
RIDDOR.
Not to current standards.
Before locking off an MCB or fuse spur, what equipment should be used when carrying out safe isolation of electrical systems?
Voltage indicator and proving unit. GS38 kit
Contactless volt stick and proving unit.
Multimeter and proving unit.
Neon screwdriver and proving unit.
What type of wet central heating appliance can supply hot water directly in a domestic dwelling?
System boiler.
Heat only boiler.
Combination boiler.
Biomass boiler.
What type of gas water heating appliance can supply instant hot water to a wash hand basin?
Combination water heater.
Multi-point water heater.
Thermal store water heater.
Solar water heater.
Which type of boiler requires an external feed and expansion system and a pump as part of the installation?
System boiler.
Combi boiler.
Heat only boiler.
Storage combi boiler.
