63
Connecting method of the mounting flange
Tighten bolts of mounting
fl
ange and process
fl
ange in a diagonal order and about three
cycles.
Removal of protective cap from process connection port
The process connection port on the low pressure side is
fi
tted with a protective cap. Before
piping, remove the cap carefully. When removing the cap, carefully protect the threaded
portion and sealing face from damage.
Connection of transmitter and impulse pipe
• The pipe on the low pressure side can be connected with an oval
fl
ange. Also, the im-
pulse pipe can directly be screwed into the transmitter. Tightening torque of 7/16-20UNF
mounting bolt in an oval
fl
ange should be 30 to 40 N·m (3 to 4 kgf·m).
• After connection, close the stop valve of transmitter in order to prevent foreign materials
from entering the inside.
Typical examples of piping
(1) Level measurement on open tank
Leave the low pressure side of transmitter open to atmosphere.
Level calculation formula:
LRV:
ρ
H
1
URV:
ρ
(H
1
+ h)
Span
(
∆
P):
ρ
h
LRV: Low limit of measurement (0%)
URV: High limit of measurement (100%)
ρ
: Measuring liquid density
H
1
: Liquid level
h: Liquid level change
(2) Level measurement on close tank
1- In case of wet leg
Connect the highest liquid level tapping of tank to the low pressure side of transmitter,
and the lowest liquid level tapping of tank to the high pressure side (
fl
ange side) of
transmitter.
Level calculation formula:
LRV:
ρ
H
1
–
ρ
0
H
2
URV:
ρ
(H
1
+ h) –
ρ
0
H
2
Span (
∆
P):
ρ
h
LRV: Low limit of measurement (0%)
URV: High limit of measurement (100%)
ρ
:
Measuring liquid density
ρ
0
:
Seal liquid density
H
1
: Liquid
level
h:
Liquid level change
H
1
R
h
Max. liquid level
Min. liquid level
H
1
h
H
2
R
0
Drain port
Stop valve
Max. liquid level
Min. liquid level
R
