Cepex STD Manual De Instalación Y Mantenimiento página 10

8. MAINTENANCE
The Cepex butterfly valve doesn't need any special maintenance if it's correctly installed, but some actions are recommended to
enlarge its life and guarantee its perfect working:
If the system doesn't have fluid due to inactivity or wintering, it is recommended to leave the valve in open position.
It is necessary to open/close the valves which are in the same position during a long time, usually once or twice per month,
specially if they are D200, D250 or D315. With this action we could decrease the overexertion caused by the inactivity and we will
increase the life of the valve.
If the valve has been closed during a long time, we recommend to open it manually the first time.
It is recommended to disassembly the valve and lubricate the gasket with solid grease in silicone base once a year, specially for the
valves with low activity.
It is recommended that the condition of the sealing gasket be regularly checked, since it may show signs of mechanical wear due
to pressure, handling and contact with the liquid. The sealing gasket should be greased in the disc contact area (the grease must
be compatible with the materials of the gasket and the disc). It is also advisable to regularly check that the flange fixing nuts are
tightened correctly, as per the recommended torque values specified above (T5.2).
8.1 VALVE EXTRACTION
A) Depressurize the installation before the extraction of the valve.
B) Clean carefully all the valve parts before disassembling it. Check for the possibility of sediments or aggressive product rests. It is
recommended to use always protection glasses and gloves.
C) Turn the disc almost to closed position.
D) Loose up the flange bolts gradually and take them off of the installation. It is possible they could be blocked, specially if no anti
galling has been used in the installation.
E) Extract the valve from the installation taking special care of the sealing gasket.
8.2 REPLACING THE SEALING GASKET
If the sealing gasket needs to be replaced, proceed as follows:
A) Ensure that the system is depressurised by releasing the pressure and emptying the pipes, following
the specific safety regulations for each product. Also check the temperature of the liquid and follow
safety standards for temperature.
B) Remove the valve from the installation.
C) Remove the actuator (section 8.3).
D) Remove the ring (8). Take off the cap (7) and remove the screw (12).
E) Tap on the shaft (6) with a rubber mallet until the bearing (4) is exposed from the bottom (Fig. 9.1).
F) Once the bearing is out, remove the shaft (6), turn it and re-insert it (Fig. 9.2) from the bottom.
G) Tap again until the bearings (4 and 5) emerge from the top. Remove the shaft again.
H) Remove the disc by pressing in the direction of the liquid flow.
I) Remove the sealing gasket. Fit the new sealing gasket; it needs to be folded and positioned so that it
lines up with the shaft, according to the gasket indicator tab (Fig. 10).
IMPORTANT: Before installing the new gasket, check the condition of the O-rings (9 and 11).
Fig. 10
Fig. 11
8
5
11
6
4
8
3
8
11
4
9
10
STD ELECTRIC BUTTERFLY VALVE
10
2
12
7
N DESCRIPTION
1 Body
2 Sealing gasket
3
Disc
4
Bearing
5 Bearing
6 Shaft
7 Cap
1
8 Elastic ring
9 Shaft o-ring
10 Washer
11
Shaft o-ring
12
Screw
ENGLISH
Fig. 9.1 Fig. 9.2
MATERIAL
PVC-U
EPDM
PVC-U
PP-GR
PP-GR
Zinc plated steel
PP
SS AISI-304
EPDM
SS AISI-304
EPDM
SS AISI-304