Yokogawa EJX438B - Manual (Page 21)

<4. Installation>
4-3
IM 01C27H01-01EN
■ When mounting the bracket on the transmitter,
tighten the (four) bolts that hold the transmitter
to a torque of approximately 39 N·m {4 kgf·m}.
IMPORTANT
• The transmitter should be installed at least
600 mm below the high pressure (HP)
process connection to ensure a positive
head pressure of fill fluid. Pay special
attention to vacuum applications.
Refer to “When the transmitter can’t be
installed at least 600 mm below the HP
process connection” if the transmitter can’t
be installed at least 600 mm below.
• Never loosen the four bolts securing the
cover flange or the screws at the joints
between the capillary tube and cover flanges
(Refer to figure 3.2.) If the seal liquid leaks,
the transmitter cannot be used.
Horizontal pipe mounting
Vertical pipe mounting
Transmitter
mounting bolt
Transmitter
mounting bolt
U-bolt nut
U-bolt nut
Mounting
bracket
Mounting
bracket
50mm (2-inch) pipe
50mm
(2-inch) pipe
U-bolt
U-bolt
F0404.ai
Figure 4.4 Transmitter Mounting
■ When the transmitter can’t be installed at least
600 mm below the HP process connection.
IMPORTANT
The transmitter should be installed at least
600 mm below the high pressure (HP) process
connection to ensure a positive head pressure
of fill fluid. Pay special attention to vacuum
applications.
If it can not be installed at least 600 mm below
the HP process connection, please use the
equation below:
h = Ч7.5Ч10 –3 [mm]
(P–P0) × dHg
ds
h: Vertical height between the HP process
connection and the transmitter (mm)
h≤0: Install the transmitter at least h (mm)
below the HP process connection
h>0: Install the transmitter at most h (mm)
above the HP process connection
P: Pressure in the tank (Pa abs)
P0: Minimum working pressure limit of
the transmitter (Pa abs) If the ambient
temperature range is –10 to 50°C.
2951 (Wetted parts material code SW, SE
and SY)
3185 (Wetted parts material code TW)
4573 (Wetted parts material code HW)
3810 (Wetted parts material code UW)
ds: Specific gravity of fill fluid (at 25°C), refer
to table 10.1 on section 10.1 General
Specifications.
dHg:Specific gravity of the Mercury 13.6 (at
25°C)