Edwards A726-01-805, Instruction Manual

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Replace the tip seals and exhaust valve
A726-01-840 Issue F
1 Replace the tip seals and exhaust valve
This instruction is applicable to the XDS replacement tip seal and exhaust valve kit (Code Number A726-01-805),
which can be used in any of the XDS5, XDS10, XDS5R, XDS10R, XDS5-C or XDS10-C scroll pumps.
For XDS pumps pre serial number 037874870 (XDS5) or 037869927 (XDS10) refer to Figure 1 . For XDS pumps post serial
number 037874870 (XDS5) or 037869927 (XDS10) refer to Figure 2 . Replace the components as described below.
1. Switch off the pump, isolate the electrical supply and allow it to cool to a safe temperature. Vent the pump
using the gas ballast control set to position 2.
2. Undo the 4 screws (410) and 4 washers (412) which secure the fan-cowl (113) to the pump-body. Remove the fan-
cowl and the fixed scroll together using a lever in the slot provided to ease it from the motor body as shown in
Figure 3 .
For pumps from serial number 066267928 the fan flying lead will need to be disconnected manually. When the scrolls
are a short distance apart, disconnect the fan from the pump body by carefully pulling the connector out of the
housing in the body.
Both tip seals (402) will now be exposed. Dispose of the tip seals in accordance with all local and national safety and
environmental requirements. If the pump has been used for anything other than clean applications, go to
Step 3 ; if
not move straight on to Step 14 .
3. Remove the gas ballast knob (if fitted) by turning to position II, pressing down and turning anti clockwise.
Remove the gas ballast knob spring (if fitted). Remove the 3 screws (130) and clamping plates (115) which clamp
the fixed scroll (101) to the fan cowl (113). Separate the fan cowl from the fixed scroll.
For XDS pumps pre serial number 037874870 (XDS5) or 037869927 (XDS10) read Step 4 to 8 and then continue at
Step 13 , for XDS pumps post serial number 037874870 (XDS5) or 037869927 (XDS10) continue at Step 9 .
4. The exhaust duct (105#) is now exposed on the outside of the fixed scroll. If the pump is an XDS-C, remove the
5 screws (117) and washers (116) securing this, and lift the exhaust duct (105#) away from the fixed scroll. If the
pump is an XDS, remove the 7 screws (117) and washers (116) securing this, and lift the exhaust duct (105#)
away from the fixed scroll.
5. Remove the O-ring (121#), valve pad (109) and spring (124). Dispose of these items in accordance with all local
and national safety and environmental requirements.
6. Separate the exhaust flange (102) from the exhaust duct (105#), exposing the exhaust duct O-ring. If you have
an XDS pump, these components are plastic and the O-ring is 128. On an XDS-C pump they are stainless steel,
and the O-ring is 137 (not illustrated). O-ring 128 is smaller than O-ring 137. Replace this O-ring and dispose of
the old one. Reconnect the exhaust flange (102) and exhaust duct (105#).
7. Fit the O-ring (121#) into the O-ring groove around the exhaust hole. Fit the exhaust spring (124) over the back
of the valve pad (109). Seat the exhaust valve pad (109) back into the hole on the fixed scroll, so that the spring
stands perpendicular to the scroll.
8. Replace the exhaust ducting, taking care not to dislodge the exhaust valve and spring. Replace the 7 screws
(117) and washers (116). Go to Step 13 .
9. The exhaust cover (105*) is now exposed on the outside of the fixed scroll. Remove the 3 screws (117) and
washers (116) securing this, and lift the exhaust cover away from the fixed scroll.
10. Remove the O-ring (121*), valve pad (109) and spring (124). Dispose of these items in accordance with all local
and national safety and environmental requirements.
11. Fit the replacement O-ring (121*) into the groove on exhaust cover (105*). Fit the exhaust spring (124) over the
back of the valve pad (109). Fit the assembled exhaust pad (109) and exhaust spring (124) onto the exhaust
cover’s (105*) spigot.
12. Replace this assembly back into the fixed scroll taking care to align the pad centrally. Whilst applying light
pressure to the back of the exhaust cover, replace the 3 screws (117) and washers (116).