ВУЗ:
Составители:
Рубрика:
83
ignition and safety controls
manufactured gas
natural gas
pipe size
pressure drop
pressure governor
specific gravity
U-tube manometer
Gas service entry into a building
The gas service pipe from the road main should slope at 1 in 20 up to the
entry point to the building, at right angles to the road main and entering the
building at the nearest convenient place. Ground cover of 375 mm is main-
tained and new pipework is made of plastic. When old steel services are re-
newed, the plastic pipe can be run inside the steel.
A meter compartment can be built into the external wall in housing instal-
lations and the service clipped to the wall under a cover. This facilitates meter
reading without entry to the property. Computer monitoring of energy meters
using a telephone link to the supply authority will eventually replace manual
reading.
Where the meter compartment is inside the building, the service should
pass through the foundations in a pipe sleeve, plugged to stop the ingress of
moisture and insects but allowing for some movement. A 300 mm square pit is
provided in a concrete floor to allow the service to rise vertically to the meter.
The pit can subsequently be filled with concrete.
The meter compartment must not be under the only means of escape in
the event of a fire in a building where there are two or more storeys above the
ground floor unless it is located in an enclosure having a minimum fire resis-
tance of half an hour.
Gas service pipes, meters and appliances should always be in naturally
ventilated spaces, as dilution with outside air is the best safety precaution
against the accumulation of an explosive mixture with air. Early detection of
Страницы
- « первая
- ‹ предыдущая
- …
- 81
- 82
- 83
- 84
- 85
- …
- следующая ›
- последняя »
