16
46-624 Series 3 Liquid Level Switches ASME B31.1 Construction
NOTE: Care must be taken not to place side force on the float which
could bend the stem.
7. With the unit resting in its temporary fixture in an upright
position, it can now be inspected or repaired.
Caution:
Do not
place the unit on its side — this could result in
damage to the stem.
8. Conduct a check for float stem straightness as follows:
8.1 Remove the stem assembly including attraction sleeve
from the head assembly by removing the two screws
holding the stop strap to the bottom of the flange.
See
Figure 20
for assembly schematic.
8.2 Check the stem straightness by aligning the stem
against a straight edge. Stems that are bent in excess
of
1
⁄
8
inch over any 6 inch length should not be used
in this condition. Replace any bent stems. See
Replacement Parts, Section 5.3.
8.3 Ensure that the components in the stem assembly are
in good condition and surfaces are clear of potential
obstructions. The stem assembly is reinstalled by
securing the stop strap to the flange. Ensure that the
attraction sleeve moves freely through the enclosing
tube and that the stem assembly surfaces are smooth.
NOTE: Care must be taken during the straightness check to ensure
the attraction sleeve is not removed from the stem and the
jam nuts settings are not changed.
9. In the container that the unit is set on, raise the liquid
level sufficiently to lift the float and trip the switch mecha-
nism. Inspect inside of chamber for any obstructions or
scale buildup. If excessive buildup is present, the interval
between inspections should be shortened. Remove old gas-
ket such that mating flange surfaces are completely clean.
Position new gasket on chamber flange before replacing
the head assembly.
NOTE: The float is restricted from moving laterally by the chamber, in
the test configuration the float and stem can move further off
center than possible under normal operation. Avoid excess
movement in this lateral direction during the test. If switch
trips, the unit may be reassembled.
10. Replace the assembly keeping it as vertical as possible.
Carefully lower the assembly into the chamber making
sure that the stem does not become bent during installa-
tion. Refer to
Figure 19
on page 15.
11. Tighten flange bolts per torque values as indicated in table
on the next page.
0.03"
Minimum
gap setting
Top jam
nuts
Bottom jam
nuts
Attraction
sleeve
Enclosing tube
(ref.)
Stop tube
Sleeve
stop strap
Retaining
screws
Float and stem
assembly
Head
flange
(ref.)
Dim. A
Figure 20
