X9 Series metering pumps Operating manual
Page 34 Copyright © - OBL Metering pumps - All rights reserved File: UT-4336 – Rev.0
GB
- if the pump is directly exposed to sunlight, or to extreme changes in temperature or if installed near heat sources
- if the handled fluid temperature can cause deformations or the pumphead
- at what actual pressure the pump works and if there is a pulsation dampener installed on the discharge
Also according to the importance and danger of the process, define an appropriate frequency for following checks:
- in case of plunger pumps, verify the plunger packing tightness (check and if necessary adjust the gland nut tightening)
- in case of diaphragm pumps, verify the pumphead leak-tight (check and if necessary adjust the tightening torque)
- verify the presence of any pumphead deformation due to the combined action of temperature and pressure
Any defect or irregularity detected during inspections should be promptly solved !
8.3 DIAPHRAGM RUPTURE DETECTOR RESETTING
Proceed as follows to reset the diaphragm rupture detector:
- check and, if necessary, adjust the pumphead tightening torque (see "Pumphead tightening torque value")
- hermetically seal the discharge valve unit and introduce in the pumphead compressed air (6÷8 bar) by means of the suction
connection. The pressure will compress the two diaphragms together, causing the expulsion of air
- wait in this condition for at least 5 minutes
- reassemble the detector (check the integrity of the pressure gauge if present and ensure that, when mounted, it indicates
"zero (0) pressure")
- restart the pump after having reconnected it to the plant and reopened the valves on the suction and discharge pipelines
- monitor diaphragm rupture detector conditions after the restart of the pump
If another signaling is given, it is reasonable to assume that one of the diaphragms is broken. It will therefore be necessary to
disassemble the pumphead to "physically" check the actual diaphragm conditions. See "Diaphragm replacement".
8.4 PUMPS TYPE LN, LP: KNOB ADJUSTMENT FRICTION SETTING
8.4.1
Increase the adjustment friction
The knob, while pump is running, does not remain on the set position. Increase the friction as follows (see figure 19):
- unscrew and keep the locking cap screws (pos.152)
- remove and keep the window cap (pos.220), and single out the ring nut locking dowel (pos.195)
- unscrew, almost completely, the ring nut locking dowel (pos.195)
- in order to increase the stiffness adjustment up to the required value, screw the ring nut (pos.150) by 5° max. at time
checking each time the amounting friction by turning the knob
- as the required stiffness is reached, lock the ring nut (pos.150) by screwing, not tightly, the locking dowel (pos.195)
- reassemble the cap (pos.220) and lock by the screws (pos.152).
8.4.2
Reduce the adjustment friction
Is difficult use the knob, the adjustment system is too stiff. Reduce the friction as follows (see figure 19):
- unscrew and keep the locking cap screws (pos.152)
- remove and keep the window cap (pos.220), and single out the ring nut locking dowel (pos.195)
- unscrew, almost completely, the ring nut locking dowel (pos.195)
- in order to reduce the stiffness adjustment down to the required value, unscrew the ring nut (pos.150) by 3° max. at time
checking each time the amounting friction by turning the knob
- as the required stiffness is reached, lock the ring nut (pos.150) by screwing, not tightly, the locking dowel (pos.195)
- reassemble the cap (pos.220) by means of the screws (pos.152).