Yokogawa EJA310E - Manual (Page 30)

<5. Installing Impulse Piping>
5-4
IM 01C25B01-01E
(7) Preventing Freezing
If there is any risk that the process fluid in the
impulse piping or transmitter could freeze, use a
steam jacket or heater to maintain the temperature
of the fluid.
NOTE
After completing the connections, close the
valves on the process pressure taps (main
valves), the valves at the transmitter (stop
valves), and the impulse piping drain valves,
so that condensate, sediment, dust and other
extraneous material cannot enter the impulse
piping.
5.2 Impulse Piping Connection
Examples
Figure 5.5 and 5.6 show examples of typical
impulse piping connections. Before connecting the
transmitter to the process, study the transmitter
installation location, the process piping layout,
and the characteristics of the process fluid
(corrosiveness, toxicity, flammability, etc.), in order
to make appropriate changes and additions to the
connection configurations.
Note the following points when referring to these
piping examples.
• The high pressure connecting port on the
transmitter is shown on the right (as viewed
from the front).
• The transmitter impulse piping connection is
shown for a vertical impulse piping connection
configuration in which the direction of
connection is either upwards or downwards.
• If the impulse line is long, bracing or supports
should be provided to prevent vibration.
• The impulse piping material used must
be compatible with the process pressure,
temperature, and other conditions.
• A variety of process pressure tap valves (main
valves) are available according to the type
of connection (flanged, screwed, welded),
construction (globe, gate, or ball valve),
temperature and pressure. Select the type of
valve most appropriate for the application.
Tee
3-valve
manifold
Drain
valve
Orifice
Drain
plug
Tap
valve
Union
or flange
Liguid Gas
Condensate pot
Steam
F0505.ai
Figure 5.5 Impulse Piping Connection Examples
for Differential Pressure Transmitters
F0506.ai
Liquid Gas Steam
Union or flange
Tee
Tee
Drain plug
Drain valve
Drain valve
Drain plug
Union or flange
Union or
flange
Union or flange
Tap valve
Tap valve
Tee
Drain valve
Drain plug
Tap valve
Figure 5.6 Impulse Piping Connection Examples
for Gauge/absolute Pressure
Transmitters