Instruction and Operation Manual
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9.5
numbers of valves, valves shall be installed on the same platform as likely as possible for
convenient of operation
.
For single valve installed at location over 1.8m and less operated, apparatus may be used such as
chain-wheel
, extension bar, move platform and move ladder etc. Where valve is installed
underground
, extension bar or ground-well shall be set. For safety reason, the ground-well shall be
covered
.
9.6
For valve installed on horizontal pipeline, the stem is suitable at uprightness position; or,
the downward stem shall be inconvenience for operation and maintenance, as well the valve is
liable to corrosion
. If the ground valve slant installed, operation and maintenance shall also be
inconvenience
.
9.7
When valves are installed in pipeline side by side, enough space shall be considerate for
operation, maintenance and dismantle. The clearance of hand-wheels shall not less than100mm;
in case of narrow clearance, valves shall be installed interleaving.
9.8
For valve with flange end, user shall select proper bolt, gasket according to the working
temperature, working pressure and fluid, equally fasten the bolts and nuts. Bolt shall be with full
thread and 8UN serial thread shall be used for bolt over 1 inch in diameter
.
9.9
For valve with butt-welding end, user shall perform welding and post welding heat
treatment using qualified WPS and welder in accordance with the requirements of ASME B31.3.
10.
Valve Operation and Maintenance
10.1
After installation and for the pressure test of the pipeline or the system, the disc must be
fully opened
. It is not recommended to use the valve as adjustment of flow rate or emergent pressure
relief blow-
off
. SPECS is not responsible for damage, loss or expense arising out of
such usage
.
10.2
Usually globe valves have no heat insulation structure, never touch the surface of valves to
prevent burn when the valve has a high/low surface temperature
.
10.3
Dust, grease and medium residual trend to accumulate at the surfaces of body, and moving
parts such as stem, gearbox, the guide of yoke etc., wear and erode the valve, and even
generate friction heat that is dangerous in explosive atmosphere
, and shall be cleaned frequently
according to the
working conditions
.
10.4
After put into service, valve shall be checked and maintained periodically especially for the
situation of sealing surfaces and worn
, the age of packing and the corrosion of body. In
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