Richter RV Series Check Valves - Manual (Page 7)

Series RV
Page 7
9550-070-en Revision 01
TM 6751 Edition 04/2007
7 Operation
7.1 Initial commissioning
Normally, the valves have been tested for leaks with
air or water. Prior to initial operation check cover
screws. For torques see Section 1.2.
Unless otherwise agreed, there could be
residual amounts of water in the flow section
of the ball valve; this could result in a possi-
ble reaction with the medium.
To prevent leaks, all connection screws should be
retightened after the initial loading of the valve with
operating pressure and operating temperature. For
torques, see Section 1.2.
7.2 Improper operation and their
consequences
Crystallisation must be prevented, e.g. by heating.
In the extreme case a blockage may occur.
Increased wear occurs in operation with solids
contents.
Increased wear occurs in operation under cavita-
tion.
Non-observance of the pressure-temperature
diagram can lead to damage.
7.3 Shutdown
The local regulations are to be observed when dis-
mantling the valve.
Prior to starting any repair work, the valve is to be
thoroughly cleaned. Even if the valve has been prop-
erly emptied and rinsed, residual medium may still
found in the valve.
8 Malfunctions
Flange connection valve/pipe is leaking
Retighten the flange screws to a tightening torque
according to Section 1.2. If this does not remedy
the leak, the recommended torques may be
exceeded by 10%.
If this also fails to stop the leak, dismantle and
inspect the valve.
Flange connection main body/body end piece is
leaking
Retighten body screws. See paragraph "Flange
connection ball valve/pipe is leaking".
Valve does not close
Are there solids between the sealing surface and
the plug?
Is the sealing surface of the seat damaged?
Is the shut off cap damaged?
9 Maintenance
All repair work is to be performed by qualified
personnel using the appropriate tools. Generally
recognised practice in mechanical engineering is
to be observed.
For the arrangement, designation and item num-
bers of all parts of the valve, see Section 10.
Spare parts are to be ordered with all the details in
acc. with the valve identification.
Only original spare parts may be installed.
To prevent leaks, a regular check of the connection
screws should be made in line with the operating
requirements.
For torques see Section 1.2. 9.1 Dismantling
9.1.1 Replacing wear parts
Screw upper 125 and lower body 126 sections
apart.
Remove the perforated plate 242.
Remove the plug stem 310 with shut-off cap 421
from the guide bush 307.
The plug stem 310 and shut-off cap 421 can be
dismantled by pulling out the PTFE round cord
522.
Replace or rework the shut-off cap 421.
Assembly is performed in reverse sequence.