ACS examination prep Flashcards
How do you convert Gross Kw into Net Kw?
Heat input (Kw gross)/ 1.11
How do you convert from heat input into flow rate (m3/h)?
(Heat input (kw) x 3.6)/38.9
What is RIDDOR reportable as a gas engineer?
Anything classed as immediately dangerous
When did the Gas safe register become the official governing body?
1 April 2009
What is GSIUR 1998?
Gas safety installation and usage regulations
What are the Gas safety (management) regulations? (A to D)
A- Safe management of Gas flow through a network supplying domestic consumers
B- Arrangements for dealing with supply emergencies
C- Arrangements for dealing with gas escapes and incidents
D- Composition of Gas
Who has right of entry according to Gas safety regulations?
Gas transporter
What is the process for RIDDOR reporting?
Notify the HSE and fill in online form within 14 days
What is the installation volume made up of?
IV of meter + IV of pipework + IV of fittings
How do you calculate Purge volume?
1.5 x Installation volume
What is the maximum installation volume allowed?
0.035 m3
What is the maximum operating pressure on the outlet of the meter?
21 +/-2 mbar
What is the maximum incoming mains gas pressure on the inlet to the meter?
2 bar
What are the pressures for intermediate gas mains?
2-7 Bar
What are the pressures for Medium gas mains?
75mbar- 2 Bar
What are the pressures for Low pressure gas mains?
Around 30mbar- 75mbar
What is the equation for complete combustion?
CH4 + 2(O2)+ignition = CO2 + (2H20) + heat
What percentage of Natural gas is Methane?
90%
What are the explosive limits for natural gas?
15% to 5%
What does a Post aerated flame look like?
Orange floppy flame
What does a Pre-aerated flame look like?
Sharp purple flame
What is flame impingement?
When flames impinge each other on a burner and the shape is changed
What is flame chilling?
When a flame makes contact with an object which reduces it’s temperature
What is vitiation?
Lack of oxygen
What is linting?
Pre-aerated burner is blocked by dust
What does F.A.G.S stand for?
Flue Air Gas Safety
What is the calorific value of natural gas?
39 Mj/m3
How much CO2 in the air means it can’t support efficient combustion?
1.5-2%
How much CO2 is in the air?
400ppm
How much CO is in the air?
109,000ppm
What are the two types of burners?
Naturally aspirated and forced draught mechanical means)
At what mbar will the gas meter lock out?
23 mbar
What is the minimum depth of screed?
75mm
An electronic token meter with a tamper device that has activated will?
Will stop gas from flowing to the outlet pipework
