Page 58 - kursus eBook

DRAFT GUIDELINE ON DOMESTIC GAS PIPING SYSTEM

o Enclosed staircase
o In rooms provided with high voltage power facilities
o Air handling room
o Unventilated void space
o Fire protected/smoke free/enclosed lift lobby areas.
o Within protected corridors or passageways which are routes of escape/exit
o Under load bearing foundations and walls

o All piping outlets shall be installed to provide sufficient clearance from ceilings, walls
and floors to permit use of a pipe wrench of suitable size without straining or bending
the pipe. The outlet fitting or piping shall not be placed behind doors.

o Each outlet, including pipe terminating with a valve, shall be securely closed gas-tight
with an approved threaded plug or threaded cap immediately after installation and
shall be left closed until an appliance is connected.

Pipe shaft or duct

Where practicable, gas pipes within the building, including gas risers, should be run
exposed. The areas through which the riser passes should be well ventilated. This will
ensure early detection of gas leaks, prevent accumulation of gasses to dangerous levels
and allow for access for maintenance.

Where a gas riser is to located in a pipe shaft (or duct), permanent ventilation to the outside
of the building should be provided to ensure that minor gas leakage does not cause the
atmosphere within the duct to become unsafe.

Where shafts are continuous, ventilation can normally be achieved by the provision of
openings at the top and bottom to the outdoors. The opening shall have a minimum free
area (in square inches) equal to the product of one-half of the maximum pressure in the
piping (in psi) times the largest nominal diameter of that piping (in inches), or the cross-
sectional area of the duct, whichever is smaller.

When a pipe shaft takes the form of an enclosure at each storey level, riser pipes shall be
fire stopped as the pass from one floor to another unless in their own protected shaft which
is ventilated top and bottom to outside atmosphere. When riser pipes from a shaft or duct
enter a flat or apartment unit they shall be fire stopped at the point of entry.

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