Yokogawa EJX438B - Manual (Page 20)

<4. Installation>
4-2
IM 01C27H01-01EN
IMPORTANT
• When measuring the liquid level of the tank,
the minimum liquid level (zero point) must
be set to a level at least 50 mm above the
center of the high pressure side diaphragm
seal (see Figure 4.2).
• Correctly install the diaphragm seals on the
high and low pressure sides of the process,
checking the label on each seal.
• To avoid measuring error duets temperature
difference between the two diaphragm
seals, capillary tube must be bound together.
The capillary tube must be securely fixed
to the tank wall to prevent movement by
wind or vibration. If the capillary tube is too
long, loosely coil the extra tube portion (coil
diameter of 300 mm or more) and secure the
coiled tube with a clamp.
• During the diaphragm seal installation,
ensure as far as possible that no seal liquid
head pressure is applied to the diaphragm
seals.
• Exercise care so as not to damage
diaphragm surfaces. Since the diaphragm
protrudes approx. 1 mm from the flange
surface, do not place the pressure detector
section face down on a surface as this can
damage the diaphragm.
• Do not sharply bend or twist capillary tube or
apply excessive stress to them.
F0402.ai
High
pressure
side
50mm minimum
Minimum
liquid level
The transmitter should be
installed as low as possible
below the position where
the high pressure side
diaphragm seal is installed.
Install the sealed diaphragm
so that the shank positions
downward.
IMPORTANT
Low
pressure
side
Figure 4.2 Installing the Diaphragm Seals to a
Tank (differential pressure transmitter)
F0403.ai
Install the sealed diaphragm
so that the shank positions
downward.
IMPORTANT
Figure 4.3 Installing the Diaphragm Seals to a
Tank (pressure transmitter)
4.3 Transmitter Mounting
■ The transmitter can be mounted on a nominal
50 mm (2-inch) pipe using the mounting
bracket supplied, as shown in Figure 4.4.
The transmitter can be mounted on either a
horizontal or a vertical pipe.