ABB SCC-S, Operator'S Manual, Page: 26 / 40

26
Replace the valve plates:
15 Separate head cap 1 from the spacer plate 3 .
16 Remove the valve plates 7 and the sealing rings 8 from the spacer plate.
17
Check that the valve seats, spacer plate and head cap are clean; if any of
them display unevenness, scratches or corrosion they should be replaced.
18 Insert the new valve plates in the valve seats on the spacer plate. The valve
plates for the compression and suction sides are identical; the same applies
to the upper and lower sides of the valve plates.
19 Move the valve plates gently in a horizontal plane to ensure that they are not
locked.
20 Insert sealing rings in the spacer plate.
Fit the pump head:
21 Move the structural diaphragm 4 by rotating the fan impeller to its upper
return point.
22
Place the intermediate plate
3
with valve plates
7
and sealing gaskets
8
and
head cover 1 on the case according to the markings.
23 Check that the head cap is centered correctly by moving it gently sideways.
24
Tighten the head cap screws
2
crosswise only slightly.
25 Check that the pump moves freely by rotating the fan impeller.
26 Move the structural diaphragm 4 by rotating the fan impeller to its upper
return point.
27
Hand-tighten the head cap screws.
Reinstall the diaphragm pump:
28 Mount the pump in the case of the sample gas feed unit.
29
Attach the hose coming from the diaphragm filter outlet to the pump inlet
and the hose going to the flow meter inlet to the pump outlet. Take care not
to bend or squash any hoses. Connect the pump's power supply leads.
30 Close and fasten the case cover of the sample gas feed unit.
Restart the sample gas feed unit:
31 Check gas path seal integrity (see section "Checking Gas Path Seal
Integrity", page 27).
32
Switch on power supply to the sample gas feed unit.
33 The sample gas flow should only be restarted after the lead time period.