SNiP 2.04.08-87*

СНиП на английском языке SNiP 2.04.08-87*

4.66. Shut-off devices designed for installation at crossings with water
barriers in accordance with Item 4.58 shall be positioned at elevation not
lower than high water horizon at 10% provision and above level of ice or
stubs and roots movement; at mountainous rivers it shall be positioned not
lower than high water horizon at 2% provision. At looped gas pipelines shutoff devices shall be located of both sides of water barrier and at single dead-end gas pipelines they shall be located on one side before the crossing (along the gas flow).
4.67. Shut-off devices designed for installation at crossings with railroads
shall be located:
on dead-end gas pipelines – not more than 1,000 m from crossing (along
the gas flow);
on looped gas pipelines – on both sides of crossing at the distance of not
more than 1,000 m from the crossing.
4.68. Wells for installation of shut-off devices shall be made of noncombustible,
wet-proof and biologically stable materials. The design and
material of wells shall rule out penetration of subsoil waters.
External wall surface of wells shall be smooth, plastered and coated with
bitumen-based hydroinsulating materials.
4.69. Encasements shall be designed at places where gas pipeline runs
through well walls.
4.70. Covers installed on concrete, reinforced concrete or other
foundations to ensure stability and rule out soil settlement shall be designed to protect control pipes, terminal leads of control and measuring instruments,
water drain pipes of condensate accumulators, hydraulic locks and valves
from mechanical damage.
4.71. To detect the position of gas pipeline installations, descriptive tables
shall be installed above or near gas pipeline (on walls of buildings or structures or on special poles).
4.72.* Steel gas pipelines shall be protected from corrosion caused by
environmental factors and earth current.
Corrosion protection of underground gas pipelines shall be designed in
accordance with the requirements of GOST 9.602—89 and normative
technical documents approved in conformity with established procedure and provisions of this sub-section.
Material of protective coating shall meet the requirements specified in
Part 11.
4.73.* Within settlements control and measuring points shall be installed
at underground gas pipelines at intervals not exceeding 200 m; outside
settlements such intervals shall not be more than 500 m; at arable lands such intervals shall be established by design. In addition, control and measuring points shall be placed at intersections of gas pipelines with underground gas pipelines of other underground metal-based utility lines (except power cables), rail tracks of electrified transport lines (in case more than two rail tracks are crossed, they shall be placed on both sides of the crossing) and at crossings of gas pipelines across water barriers more than 75 m wide.
At gas pipeline intersections with other gas pipelines or other underground utility lines the need to install control and measuring instruments shall be decided by the design organization in accordance with corrosive conditions.
4.74. Shut-off devices, condensate accumulators and other gas pipeline equipment and installations can be used to measure protective electric potential of gas pipelines.