Yokogawa EJX430B - Manual (Page 38)

<7. Operation>
7-6
IM 01C27B01-01EN
7.6 Venting or Draining
Transmitter Pressure-
detector Section
Since this transmitter is designed to be self-
draining and self-venting with vertical impulse
piping connections, neither draining nor venting
will be required if the impulse piping is configured
appropriately for self-draining or self-venting
operation.
If condensate (or gas) collects in the transmitter
pressure-detector section, the measured pressure
may be in error. If it is not possible to configure the
piping for self-draining (or self-venting) operation,
you will need to loosen the drain (vent) screw on the
transmitter to completely drain (vent) any stagnated
liquid (gas.) After venting or draining, fasten the
drain (vent) screw on the transmitter.
IMPORTANT
Draining condensate or bleeding off gas disturbs
the pressure measurement, this should not be
done when the loop is in operation.
7.6.1 Draining Condensate
1) Gradually open the drain screw or drain plug
and drain the transmitter pressure-detector
section. (See figure 7.7.)
2) When all accumulated liquid is completely
removed, close the drain screw or drain plug.
3) Tighten the drain screw to a torque of 10 N·m,
and the drain plug to a torque of 34 to 39 N·m.
WARNING
Since the accumulated liquid (or gas) may be
toxic or otherwise harmful, take appropriate care
to avoid contact with the body, or inhalation of
vapors.
When you loosen the drain screw or drain
plug, the accumulated liquid will be expelled
in the direction of the arrow.
F0711.ai
Drain screw
Drain plug
Figure 7.7 Draining the Transmitter
7.6.2 Venting Gas
1) Gradually open the vent screw to vent gas from
the transmitter pressure-detector section. (See
figure 7.8.)
2) When the transmitter is completely vented,
close the vent screw.
3) Tighten the vent screw to a torque of 10 N·m.
WARNING
Since the accumulated liquid (or gas) may be
toxic or otherwise harmful, take appropriate care
to avoid contact with the body, or inhalation of
vapors.
When you loosen the vent screw, the gas
escpes in the direction of the arrow.
F0712.ai
Vent screw
Vent screw
Figure 7.8 Venting the Transmitter