Yokogawa EJA438 - Manual (Page 19)

IM 1C22J1-01E 4-1
4. INSTALLATION
4. INSTALLATION
4.1 Precautions
᭿ Before installing the transmitter, read the cautionary
notes in Section 2.4, “Selecting the Installation
Location.” For additional information on the
ambient conditions allowed at the installation
location, refer to Subsection 9.1 “Standard Specifi-
cations.”
IMPORTANT
• When welding piping during construction, take
care not to allow welding currents to flow
through the transmitter.
• Do not step on this instrument after installation.
4.2 Mounting the Diaphragm
Seals
Mount the diaphragm seals using the flanges as shown
in Figure 4.2.1. Figure 4.2.2 shows how to mount the
diaphragm seals on a tank. The customer should
prepare the mating flange, gasket, bolts and nuts.
Nut
Flange
Diaphragm
ød
Gasket
F0401.EPS
Bolt
The product is shipped with
these parts assembled.
Correctly install the diaphragm seals on
the high and low pressure sides of the
process, checking the label on each seal.
Figure 4.2.1 Mounting the Diaphragm Seals
IMPORTANT
Please use a gasket which has a bigger inside
diameter than that of gasket facing (ød) on
diaphragm seal. In case a gasket which has a
smaller inside diameter than that of gasket
facing is used, it may cause an error as the
gasket prevents diaphragm from working cor-
rectly. (Refer to Subsection 9.4 ‘Dimensions’)
IMPORTANT
• During the diaphragm seal installation, ensure
as far as possible that no seal liquid head is
applied to the diaphragm seal.
• Exercise care so as not to damage diaphragm
surface. Since the diaphragm protrudes approx.
1mm from the flange surface, placing the
diaphragm seals with its diaphragm surface
facing downward may damage the diaphragm
surface.
• Do not sharply bend or twist capillary tube or
apply excessive stress to it.
F0402.EPS
Diaphragm seal
Capillary tube
IMPORTANT
Install the sealed diaphragm
so that the shank positions
downward.
Figure 4.2.2 Installing the Diaphragm Seals to a Tank
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 4.3.1 The transmitter
can be mounted on either a horizontal or a vertical
pipe.
᭿ 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
Never loosen the four screws securing the cover
flange or the screws at the joints between the
capillary tube and cover flanges (if the seal liquid
leaks, the transmitter cannot be used).