Flowserve Torex butterfly valves - Manual (Page 4)

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2. Remove the bolts, retainer ring (6), gasket (8)
and seat ring (10). Use the two tapped holes
(M6) in the retainer ring to remove the ring from
the valve body.
3. Carefully wash all parts. First use warm water
and then, if necessary, a suitable solvent. Do not
scrape any of the machined surface with hard
tools.
4. Examine the surfaces on the periphery of the
valve disc. Minor scratches and marks on the
sealing surface can be rubbed down with emery
paper.
5. Inspect the seat ring. During such overhauls, it is
always advisable to fit a new seat ring.
6. Refit the gasket (8).
7. Spray the valve disc, sealing surface and seat
ring with a suitable lubricant, such as Molykote
321 R or Gleitmo 900 or Unimoly C 220. Allow
the lubricant to dry for at least 15 minutes.
8. Fit the seat ring (10) and retainer ring (6) into
the valve body.
9. Screw in the retainer ring bolts, but don’t tighten
the retainer ring.
10. Check that the A-measure is correct according to
9.5.
9.3 To replace EPDM and FPM seat rings.
1-4 See the corresponding items in section 9.2.
5. Carefully clean the groove in the body into which
the seat ring is mounted.
6. Turn the valve disc almost to the closed position
(about 2° from the closed position) and lock it in
this position.
7. Spray the seat ring with a PTFE lubricant, such
as Fluor Carbon 1094, and fit the ring into its
seat in the body. Fit the retainer ring (6) over the
seat ring and clamp it in position with its bolts.
Tighten one pair of diagonally opposite bolts,
then a pair of diagonally opposite bolts at right
angles to the first pair, and so on until the
retainer ring is firmly in position.
Set the position of the valve disc in accordance
with the stamped dimension A as shown in
Fig. 4.
8. Spare parts
State the following data when ordering spare parts:
1. Product code of the valve - incl. DN according to
Fk 41.42 and the Manuf. No. specified on the
identification plate of the valve.
2. Description of the part, its item No and quantity
required. See table section 7.
Ordering example: 2382BB-0200-05,
manuf. No 1234567,
Seatring item10.
Quantity 1 st.
9. Maintenance
If the valve disc or seat ring has sustained damage due to
impurities in the pipework or for some other reason, or if
the seat ring and shaft seals need replacing after a long
period of service, the valve must be overhauled.
Many valves are installed in such locations that their
performance is of decisive importance to the entire
process. Such valves should be inspected regularly and
any faults should immediately be corrected.
9.1 To remove the valve from the pipework
The procedure for inspection and maintenance, for which
no special tools are necessary, is as follows:
Ensure that the valve is not under pressure.
1. Ensure that the recommended spare parts and
also the gaskets for the pipe flanges are
available.
2. Close the valve.
3. Shut off all compressed air connections and
isolate all electrical connections to the actuator.
4. Disconnect all compressed air lines and electric
cables connected to the actuator.
5. Note the direction of flow which is shown by an
arrow on the valve body.
6. Release the flanged joint between the valve and
the pipework. Then lift out the valve. Apply all
lifting forces to the valve itself and not to the
actuator.
9.2 To change an Inconel seat ring
If an actuator is fitted to the valve, it need not be removed
for inspection and replacement of the seat ring.
1. Set the valve to the fully open position.