Purging Volume

• All air and gas mixtures have to be removed before commissioning an appliance
• Inform the customer and put up notices if necessary
• Open the ECV and note the meter
• The following chart shows how much gas should be purged:
  

  Meter	Pipework Purge Volumes
  E6, G4, U6 Pipework ≤28mm	0.01m3
  U6, G4 35mm ≤ pipework > 28mm	0.01m3 + 1.5 x Vp*
  E6 35mm ≤ pipework > 28	0.0036m3 + 1.5 x Vp*
  G10, U16 pipework ≤ 32mm	0.03m3 + 1.5 x Vp*
  *Vp - volume of pipes and fittings

• If the volume is 0.02m³ or less the gas can be purged into the building
  • if more than 0.02m³ a temporary burner must be installed
• Open the appliance furthest from the meter
• Establish a stable flame at each appliance
  

When to carry out?

• New installation
• Alteration to, replacement of, or re-use exciting installations
• New extensions to existing pipework
• Where there has been a complete loss of pressure for any reason
• Where there is the possibility of air being present in an installation
• Where an installation is to be taken out of service temporary or permanently