Operation Manual

8-5
IM 1F5B2-01E
8. MAINTENANCE
8.3 Disassembly and Reassembly
When disassembling or reassembling ULTRA YEWFLO for a part replacement or
maintenance, ALWAYS turn off both the flowmeter and flow of the process fluid. Use
the appropriate tools for the disassembly/reassembly of ULTRA YEWFLO.
CAUTION
• The maintenance work described hereinafter can be done at the location where
ULTRA YEWFLO is installed if it is a standard model. If your ULTRA YEWFLO is
an explosion-protected model, however, it is an established rule that you relocate it to
a non-hazardous area, do the maintenance work, and then reassemble it in its original
form. See “Installation and Operating Precautions for Flameproof Explosion-Pro-
tected Instruments” at the end of this manual for more information.
• No user modification is permitted on flameproof models of ULTRA YEWFLO. You
therefore are not allowed to add any additional indicator/totalizer component to those
models of ULTRA YEWFLO nor can you use ULTRA YEWFLO with the compo-
nent removed. If such modification is unavoidably necessary, consult Yokogawa
Electric Corporation.
• When disassembling a flameproof model of ULTRA YEWFLO, first turn the lock
screw clockwise with a special tool (Allen wrench) to unlock the cover, and then
remove the cover. After having replaced the cover, ALWAYS turn the lock screw
counterclockwise to lock the cover.
8.3.1 Removing the Indicator/Totalizer Component
• When removing the indicator/totalizer component to change the way it is viewed,
follow the procedure described below.
<1> Turn off ULTRA YEWFLO.
<2> Remove the cover on the converter.
<3> Using a flat-blade screwdriver, remove the two setscrews from the indicator/
totalizer component.
<4> Take the component out by hand.
<5> When reassembling the component into the converter after the component is
repositioned, follow these steps in their reverse order, while aligning the
component’s screw holes with the bolts in the converter and then fastening the two
set screws.