Page 73 - B8773-AEW-XX-XX-PP-A-0001_[P4]_Contractors Manual
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D R A F T


          4.3.3 Best Practice Guidance
          Ventilation                                           Below ground entry connections
          Where the gas meter is to be located internally       In stores where the gas connection is entering
          and within a purpose built cupboard, adequate         the  building  below  ground  level  a  sand  filled
          ventilation must be provided.                         entry pit must be provided.
          •  The  ventilation  must  be  2%  of  the  nominal
             floor area                                         Best practice
          •  The ventilation must be both high and low          •  Excavate a pit which allows the service pipe
             level                                                  to enter the building
          •  The  housing  in  which  the  meter  is  located   •  Gas service pipe must be minimum 450mm
             must be completely sealed so gas can only              below ground level
             escape from the housing / cupboard to the          •  Gas service pipe must enter the building to
             external atmosphere                                    a minimum length of 450mm before it can
                                                                    bend to rise above the floor level and must
          In the event of a gas leak, the gas must not be           have a further 450mm from the gas service
          able to  escape into  the  room  the  cupboard            pipe to the inner side of the pit
          is located,  behind  boarded  walls or  to  upper     •  The pit must then be filled with sand
          floors or other parts of the building.


          Best Practice
          •  Install air bricks at high and low level within
             the  cupboard  (so  gas  can  escape  to  the
             external atmosphere)
          •  Ensure the cupboard is fully boarded and
             sealed.  (Gas can  become  trapped  and
             permeate in the void between the wall and
             the boarding)
          •  Ensure the top of the housing has a ‘ceiling
             / roof’ and no upper floors can be seen (as
             gas  will  seep  through  and  travel  to  upper
             parts of the building)



















          4.3.3                      Best Practice Guidance                                 5 January 2018
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