YOKOGAWA AXG1A Installation Manual page 15

(3) Installation of Gasket and Grounding
Device
The gaskets (supplied by customer) used for connection
with customer pipes differ by the presence or absence of
grounding device (grounding ring) and the specifications
selected. Be sure to use the gaskets in compliance
with the flange ratings and fluid specification. Install the
gaskets as the followings.
Be sure to choose gaskets with inner and outer diameters
that do not protrude inside the piping by referring to
Subsection 3.3.3.
WARNING
• All gaskets used for piping of magnetic flowmeters
should be prepared by customers except in some
cases.
For the following cases, be sure to use a gasket
between the grounding ring and the lining flare
section, to prevent fluid leaks.
- Size 50 to 200 mm (2 to 8 in.), natural hard rubber
lining, and with grounding ring are specified.
- Grounding rings are added at a later time.
• Be sure to choose the gasket with hardness
comparable to soft rubber or the PTFE-sheathed
non-asbestos gasket, or the equivalent in hardness
gasket depending on process pressure. The
thickness of the gasket should cover the range
shown in Table 3.3.1.
Table 3.3.1 Gasket thickness
Size mm
50 to 125 (2 to 5 in.)
150 to 200 (6 to 8 in.)
For size 25 to 125 mm, the grounding ring has mounting
fixing brackets (See Figure 3.3.1).
Figure 3.3.1 Mounting of grounding ring
Gasket thickness (mm)
2
3
Gasket
Grounding ring
Screw
F0309.ai
<3. Installation>
• Installation: Natural hard rubber lining type and
Metal pipe
When a magnetic flowmeter with natural hard
rubber lining is installed to metal pipe without
lining, installation method without grounding ring is
recommended.
With grounding wire (supplied by customer), connect
between the pipe and the sensor mini-flange, or
between the transmitter and the grounding terminal of
terminal box. For grounding in detail, read Subsection
4.4.3.
For gasket A (customer pipe side), use non-asbestos
joint sheet gasket, PTFE-sheathed non-asbestos joint
sheet gasket (optional code BSF) or gasket with the
equivalent hardness.
In the case grounding ring is used, for gasket B
(sensor side), use non-asbestos joint sheet gasket,
PTFE-sheathed non-asbestos joint sheet gasket
(optional code BSF) or gasket with the equivalent
hardness.
It is recommended to use gasket with same hardness
for gasket A and B.
• Installation without grounding ring
Customer pipe
(Metal)
A
With grounding wire, connect between the pipe and the sensor mini-flange,
or between the transmitter and the grounding terminal of terminal box.
Gasket A
to be supplied by customer or by specified optional code
• Installation with grounding ring
Grounding ring
Customer pipe
(Metal)
A B
Gasket A
to be supplied by customer
Gasket B
to be supplied by customer, or to be supplied by specified optional code
14
Customer pipe
(Metal)
A
F0310.ai
Customer pipe
(Metal)
B A
F0311.ai
IM 01E24A01-01EN