Mounting EjC80 With Direct Mount Seal; Mounting; Connecting Impulse Piping To The Transmitter - YOKOGAWA DPharp EJXC80A User Manual

4.5 Mounting EJC80 with
Direct Mount Seal

4.5.1 Mounting

The transmitter is mounted on a process using its
high-pressure side flange as shown in Figure 4.7.
The mating flange, gasket, stud bolts and nuts are
to be procured by the customer.
Gasket
Nut
Figure 4.7 Transmitter Mounting
IMPORTANT
Please use a gasket with an inside diameter
(ød) that is greater than the diameter of the
diaphragm seal. If a gasket with a smaller
inside diameter is used, the diaphragm may not
function correctly. (Refer to 'Dimensions' in the
chapter 7.)
4.5.2 Connecting Impulse Piping to the
Transmitter
The impulse piping that connects the process
outputs to the transmitter must convey the process
pressure accurately. If, for example, gas collects in
a liquid-filled impulse line, or the drain of a gas-filled
impulse line becomes plugged, it will not convey the
pressure accurately. Since this will cause errors in
the measurement output, select the proper piping
method for the process fluid (gas, liquid, or steam).
Pay careful attention to the following points when
routing the impulse piping and connecting the
impulse piping to a transmitter.
Stud bolt
F0407.ai
<4. Installation>
(1) Check the High and Low Pressure
Connections on the Transmitter (Figure 4.8)
The letters H and L on the capsule assembly
indicate the high and low pressure sides. For
liquid level measurement in an open tank, the low
pressure side measures atmospheric pressure.
For a closed tank, connect the impulse line to the
low pressure side of the transmitter to measure the
pressure in the tank.
Figure 4.8 H and L Symbols on a Capsule
Assembly
(2) Tightening the Process Connector
Mounting Bolts
After connecting the impulse line, tighten the
process connector mounting bolts uniformly.
(3) Removing the Impulse Piping Connecting
Port Dustproof Cap
The impulse piping connecting port of the
transmitter is covered with a plastic cap to keep out
dust. This cap must be removed before connecting
the line. (Be careful not to damage the threads
when removing this cap. Never insert a screwdriver
or other tool between the cap and port threads to
remove the cap.)
(4) Impulse Piping Slope
The impulse piping must be routed with only an
upward or downward slope. Even for horizontal
routing, the impulse piping should have a slope of
at least 1/10 to prevent condensate (or gases) from
accumulating in the pipes.
(5) 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.
4-5
H and L appear here
Low pressure
connection
Process connector
Bolt
F0408.ai
IM 01C25W01-01EN