30
SCC-F Sample gas feed unit Operator’s manual
42/23-51 EN Rev. 3
Replacing the diaphragm and valve plates,
continued
Replace diaphragm
and valve plates in the
diaphragm pump
(continued)
Step Action
Replace valve plates:
13
Separate head cap
1
from the spacer plate
3
.
14
Remove the valve plates
7
and the sealing rings
8
from the spacer
plate
3
.
15
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.
16
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.
17
Move the valve plates gently in a horizontal plane to ensure that they
are not locked.
18
Insert sealing rings in the spacer plate.
Fit the pump head:
19
Using the fan impeller, move the structural diaphragm to its upper dead
point.
20
Place the spacer plate
3
, the valve plates
7
, sealing rings
8
and the
head cap
1
on the casing in accordance with the markings.
21
Check that the head cap is centered correctly by moving it gently
sideways.
22
Tighten the head cap screws
2
crosswise only slightly.
23
Check that the pump moves freely by turning the fan impeller.
24
Using the fan impeller, move the structural diaphragm to its upper dead
point.
25
Hand-tighten the head cap screws.
Reinstall diaphragm pumps:
26
Connect pump hoses.
27
Insert mounting plate with the pumps into the sample gas feed unit’s
casing and fasten it with the two hex socket head screws
1
. Connect
electrical connection
2
.
Start the sample gas feed unit again:
28
Check that the gas paths have no leaks (see instructions on page 31).
29
Switch on power supply to feed unit.
30
The sample gas flow should only be restarted after the lead time
period.
