Regulations

• Regulations 22 and 23 - Gas Safety (Installation and Use) Regulations 1998
• IGE/UP/1B Edition 2, Tightness Testing and Purging of Small Natural Gas Installations

When to carry out?

• Smell of gas
• New pipework installation (before it painted or covered)
• After alteration to, replacement of, or re-use exciting installations
• Prior to any work on exciting pipework
• After work on a gas fitting
• Yearly in rented accommodation
  

Pressure Gauges

• Water Gauge (U-gauge manometer)
  
  

• indirect reading type (division = 1mbar) and direct reading type (division = 2mbar)
• Accuracy is 0.5mbar
• 300mm - size for natural gas (measures up to 30mbar)
• 1m - size for LPG
• Water level SHOULD be set at 0
• Maximum 0.2 mbar perceptible movement
• Electronic Gauge
  • MIN accuracy - 0.3mbar
  • Must be calibrated and certificated annually
  • Maximum 0.25 mbar perceptible movement
    

Soundness Test Procedure

• Domestic tightness testing if:
  • Meter volume in not greater 16m³/h
  • Meter Operating Pressure is up to 2Bar
  • Maximum 35mm gas installation
• Let-by Test (ECV is not letting by)
  • rise the pressure to 10mbar
  • isolate the supply
  • maximum 0.5 mbar drop over the next 1 minute
  • National Gas Emergency Call Center shall be notified if ECV is passing the gas when closed
• Tightness test:
  • Turn off all pilot lights
  • rise the pressure to 20mbar (meter regulator can lock up if higher)
  • left for 1 minute for temperature stabilization
  • no more than 0.5mbar pressure loss within next 2 minutes
  • No pressure drop permitted
    • for installations without appliances
    • for new installations
    • for gas meter
    • for new appliances

Maximum Permissible Pressure Loss

• Pipe Diameter	Ultrasonic meter (up to 6 m3/h) E6 or no meter	Diaphragm meter (up to 6 m3/h) U6/G4	Diaphragm meter (> 6 m3/h and up to 16 m3/h) U16/E10
  Up to 28mm	8 mbar	4 mbar	1 mbar
  >28mm and up to 35mm	4.5 mbar	2.5 mbar	1 mbar

• Pipework only test:
  • rise the pressure to 20mbar (meter regulator can lock up if higher)
  • left for 1 minute for temperature stabilization
  • no more than 0.5mbar pressure loss within next 2 minutes
• Governor lock-up
  • The governor at the meter is set to give a working pressure of 21mbar (±2mbar)
  • If the pressure goes above 23mbar the valve will be forced into seating (lock up)
  • This would result in the pipe from the ECV to the governor not being tested