I.S. 821:2006

DECLARATION
Foreword
1 Scope
2 Normative references
3 Terms and definitions
4 I.S. EN 12186
5 Quality system
6 Layout of the gas pressure regulating station
   6.1 General
   6.2 Proximity requirements
   6.3 Layout of the site
   6.4 Site security
7 Housings
   7.1 General
   7.2 Requirements for housings
   7.3 Underground stations
        7.3.1 General
        7.3.2 Stations in a pit
        7.3.3 Buried vessel type stations
8 Design of the station
   8.1 General
   8.2 Gas pre-heating
   8.3 Filters, separators, scrubbers
   8.4 Noise control
        8.4.1 General
        8.4.2 Environmental acceptance
        8.4.3 Work area noise
   8.5 Apertures and vent lines
        8.5.1 Apertures
        8.5.2 Vent lines
   8.6 Electrical installation
   8.7 Lightning and earthing
   8.8 Cathodic protection and electrical isolation
   8.9 Ancillaries
   8.10 Pipework
   8.11 Welding
   8.12 Instrumentation pipework
   8.13 Stress analysis
        8.13.1 General
        8.13.2 Design pressure
        8.13.3 Design factor
        8.13.4 Supports
        8.13.5 Flexibility
        8.13.6 Temperature
        8.13.7 Gas velocity
   8.14 Isolating valves
        8.14.1 Supports
   8.15 Isolating valves
9 Pressure control
   9.1 General
   9.2 Pressure regulating system
   9.3 Pressure safety system
        9.3.1 General
        9.3.2 Operating principles of pressure safety
               systems
        9.3.3 Applications
   9.4 Non-venting pressure safety devices
        9.4.1 Safety shut-off devices
        9.4.2 Monitors
   9.5 Venting pressure safety devices
        9.5.1 General
        9.5.2 Creep relief valve
   9.6 Pressure warning system
   9.7 Instrumentation
   9.8 Bypasses
        9.8.1 Temporary bypasses for equalization or
               testing
        9.8.2 Bypasses of the pressure control and/or
               safety system
10 Testing
   10.1 General
   10.2 Strength test
        10.2.1 General
        10.2.2 Installations with MOP up to and including
               16 bar
   10.3 Tightness test
   10.4 Reporting
11 Commissioning
12 Operation and maintenance
   12.1 General
   12.2 Data
   12.3 Maintenance
   12.4 Training
   12.5 Work undertaken
   12.6 Firefighting
   12.7 Maintenance review
Annex A (normative) Proving tests
      A.1 Safety
      A.2 General
      A.3 Test equipment
      A.4 Pneumatic tests
      A.5 Hydrostatic tests
      A.6 Test certificates and records
Bibliography

Specifies the minimum requirements applicable to the design, materials, construction, testing, operation and maintenance of gas pressure regulating stations which form part of a gas distribution system.