6.2
Installation position
The valve bodies are marked with an arrow indicating the
flow direction. Valves should always be installed in such a
way that the actual flow direction of the medium matches the
arrow on the body.
6.2.1 Gate valves
In general flow may pass a gate valve in either direction.
However in high pressure valves with pressure relieving
arrangement valves are unidirectional. When installing a
gate valve in a horizontal pipe, the stem should be vertical,
i.e. the handwheel or actuator is on top. Inclined or horizontal
stem position (e.g. in a vertical pipe) is also possible, in this
case, however, the actuator must be supported by some
suitable means.
6.2.2 Globe valves
Flow may pass a globe valve in either direction if not
indicated otherwise. When installing a globe valve in a
horizontal stem position (e.g. in a vertical pipe) is also
possible, in this case, however, the actuator must be
supported by some suitable means.
6.2.3 Swing Check valves
Swing check valves should preferably be installed in
horizontal pipes. When installing them in vertical pipes, make
sure that the flow direction is upward, so that in the
unpressurized condition, the disc will be closed by its own
weight.
6.2.4 Piston Check valves
Piston check valves should preferably be installed in
horizontal pipes. Installing them in vertical pipes is not
allowed because the blocking between disc and body may
occur.
6.3
Welding instructions / installation of pipe
Responsibility for welding the pipes lies with the piping
installation contractor.
When welding valves on to the piping or when
welding pipes after the valves have been
installed, the welder must make sure that no foreign particles,
e.g. weld beads, enter the valve body and remain there,
because these will cause damage to the valve seats and or
the valve stem.
When welding these valves, use adequate
precautions, e.g. welding in several steps, to
make sure that the temperature in the middle of the body
does not rise above 80 to 100 . Gate valves / Globe valves
must be in open position during welding to prevent the
sealing elements from contacting body sealing surface
otherwise the seats may be welded together.
Do not attach the welding cables (opposite
pole) to the moveable parts of the valve,
otherwise these parts may be scorched.
6.4
Actuated valves
Read the instruction manual of the actuator
before installation.
Electrical cables may only be connected by
qualified personnel.
The applicable electrical regulations (e.g. VDE),
also for equipment in hazardous locations, must
be observed.
All electrical equipment such as actuator, switchboard,
magnetic valve drive, limit switch etc. must be installed in
floodproof dry locations.
Voltage and frequency must match the valves stated on the
name plate.
7
Commissioning / Decommissioning
7.1
Commissioning
7.1.1 General
Prior to commissioning the valve, the pressure, temperature
and material data stated on the valve should be compared to
the actual operating conditions in the piping system to check
whether the valve can withstand the loads occurring in the
system.
Possible pressure surges (water hammer) must not
be exceed the highest admissible pressure.
Adequate precautions should be taken.
Caution
Caution
Caution
Caution
