3.4 Affixing The Teflon Film - YOKOGAWA Dpharp vigilantplant EJA Series Manual

IMPORTANT
The transmitter should be installed below the high
pressure (HP) process connection to ensure a
positive head pressure of fill fluid. The recommended
height between the HP process connection and the
transmitter is show in the following table. Pay special
attention to vacuum applications.
Model
EJA118
EJA438W Wetted parts material code S,
T, U, EJA438N
EJA438W Wetted parts material code H
Wetted parts material code
If it can not be installed below the HP process
connection with the recommended height above,
please use the equation below:
(P–P0)×dHg
h= ×7.5×10
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
(ambient temperature range: -10 to 50°C)
EJA118
Wetted parts material
S
code
P0: Minimum working
3178
pressure limit
EJA438
Wetted parts material
S
code
P0: Minimum working
5254
pressure limit
ds: Specific gravity of fill fluid (at 25°C)
Fill fluid code A
1.07
ds: Specific gravity
dHg: Specific gravity of the Mercury 13.6 (at 25°C)
Wetted parts material code
Height (h)
600 mm
700 mm
1,300 mm
–3
[mm]
T H U
3596 6074 4711
T, U H
6980 13019
B C, E D
1.90 to
0.94 1.09
1.92
Fill fluid code
<3. Installation>
Low
pressure side
h
(+)
0
(–)
Figure 3.8 Example of Installation to Tank
(Caution on Installation)
3.4 Affixing the Teflon Film
IMPORTANT
The FEP Teflon option includes a teflon film and
fluorinated oil. Before mounting the transmitter to the
process flange, affix the teflon film as follows:
1) Position the diaphragm so that the diaphragm is in
an upward position.
2) Pour the fluorinated oil on the diaphragm and
gasket area covering it completely and evenly. Be
careful not to scratch the diaphragm or change the
its shape.
3) Affix the teflon film over the diaphragm and gasket
area.
4) Next, carefully inspect the cover and try to identify
any entrapped air between the diaphragm and
the teflon film. The air must be removed to ensure
accuracy. If air pockets are present, use your
fingers to remove the air by starting at the center of
the diaphragm and work your way out.
5) Place the gasket with the teflon film and affix to the
process flange.
Fluorinated oil
[PART No. : F9145YN]
Figure 3.9 Affixing the Teflon Film
17
P
High
pressure side
F0308.ai
Teflon film
PART No.
EJA210A F9347YD
2B
EJA118W
(50A)
F9347YA
EJA438W
3B(80A) F9347XA
Diaphragm
Gasket area
F0309.ai
IM 01C22A01-01E
3