Yokogawa EJA115 - Manual (Page 61)

IM 01C22K01-01E 9-5
9. MAINTENANCE
9.4.4 Cleaning Manifold Assembly and
Replacing Orifice
This subsection describes the procedures for cleaning
the manifold assembly and replacing the orifice to
change flow rate. (See Figure 9.4.4.)
᭿ Removing the Manifold Asssembly
1) Remove the process connector as shown in Subsec-
tion 9.4.3.
2) Remove the four bolts that connect the cover flange
with the manifold.
3) Remove the spacer, orifice, and orifice gasket from
inside the manifold.
4) Clean the manifold, spacer, and orifice, or replace
them as necessary.
IMPORTANT
Exercise care as follows when cleaning the
manifold assembly.
• Handle the manifold assembly with care, and
be careful not to damage the inner part of the
manifold, spacer, and orifice. Be especially
careful not to damage or distort the orifice edge
(orifice bore).
• Do not use a chlorinated or acidic solution for
cleaning.
• Rinse thoroughly with clean water after clean-
ing and dry thoroughly.
᭿ Reassembling the Manifold Assembly
1) Reassemble the orifice gasket, orifice, and spacer
into the manifold in that order.
When reassembling, refer to Figure 9.4.4 to ensure
that they are placed in the correct direction.
Replace the orifice gasket with a new gasket.
2) Mount the process connector as shown in Subsec-
tion 9.4.3.
3) Mount the manifold on the cover flange with the
four bolts. Tighten the four bolts uniformly to a
torque of 39 to 49 N·m {4 to 5 kgf·m}.
Replace the manifold gaskets with new gaskets.
4) After completing reassembly, a leak test must be
performed to verify that there are no pressure leaks.
NOTE
Exercise care as follows when reassembling the
manifold assembly. (See Figure 9.4.4.)
• Be careful not to reassemble the orifice in the
wrong direction. Note that the spacer is config-
ured so that it cannot be placed in the reverse
direction.
• When mounting the manifold on the cover
flange, confirm the indication “flow direction”
shown on the manifold surface and the high
and low pressure sides of the pressure-
detector section.
Mount the manifold so that the upstream side
of process fluid flow is located at the high
pressure side of the pressure-detection sec-
tion.
F0905.EPS
Process connector
gasket
Process connector
gasket
Spacer
Orifice
Bolt
Orifice gasket
Manifold gasket
Cover flange
Manifold
Low pressure side
High pressure side
Figure 9.4.4 Manifold Assembly