Chapter 5: Maintenance Of The B Series Ldpu; Troubleshooting And Solving Problems - OMAC B Series Operation And Maintenance Manual

Rev.4 del 01/2011 O.M.A.C. s.r.l.
Where provided, the contents of this chapter is specifi cally addressed to the internal company maintenance operator. This person, named directly
and formally by the Customer company management; has at least two years experience in this role and has the required technical abilities for operating
in safety conditions and interpret the technical indications contained in the above mentioned documentation properly.
DANGER
Before disconnecting the LDPU from its energy supplies, make sure that the plant or part of it is contained in complies with the following conditions:
• absence of product and eventually washing;
• absence of residual pressure;
• temperature of contact surfaces not dangerous.
Before carrying out any maintenance operation on the LDPU pump, ensure one has carried out the pump and plant stopping operations, described in
section 4.5 "Use of the line: stopping instructions"
During the LDPU assembly and disassembly operations, as during its routine and extraordinary maintenance, one must wear the personal protection
equipment, according to the operation and risk connected to the activity performed by the appointed operator, as described in section 1.9.

5.1 Troubleshooting and solving problems

POSSIBLE CAUSES:
Excessive medium viscosity
Low medium temperature
Excessive back-pressure
Too tight packing gland
Excessive pump speed
Piping press on pumping case
Not aligned joint
Worn out bearings
Worn out or untimed gears
Wrong quantity / quality of gears oil
Parts in contact in the pumping case
Worn out rotors
POSSIBLE CAUSES:
Excessive medium viscosity
Low media temperature
Excessive back-pressure
Worn out or untimed gears
Parts in contact in the pumping case
POSSIBLE CAUSES:
Insuffi cient N.P.S.H (Net Positive Suction Head)
Medium evaporates in inlet
Air enters in inlet
Presence of air in the suction
Not enough liquid level in the tank in the suction
Dirty or blocked valve or suction fi lter
FAILURE: HIGH POWER ABSORPTION BY GPVL
Decrease the speed of the pump, increase the temperature of the medium
Increase the temperature of the medium, heat the pumping case (within the limits given by the manufacturer)
Remove possible obstructions in the outlet piping, increase the piping diameter, reduce its lenght and the number of the
bends
Loosen the packing gland and tighten it rightly (see instructions)
Decrease the speed of the pump
Check the piping alignement, if necessary fi t fl exible expansion joints, and fi x the piping on the plant structure
Check the alignement between pump and drive device
Replace the bearings by the manufacturer
Replace the gears or time them according to the instructions
Act according to the manufacturer's instructions
Check the design pressure coincides with the operating pressure
Replace rotors
FAILURE: GPVL JUST STARTING BLOCK
decrease the speed of the pump, increase the temperature of the medium
increase the temperature of the medium, heat the pumping case (within the limits given by the manufacturer)
Remove possible obstructions in the outlet piping, increase the piping diameter, reduce its lenght and the number of the
bends
replace the gears or time them according to the instructions
Check the design pressure coincides with the operating pressure
FAILURE: UNPRIMED OF THE PUMP
Increase the head, the piping inlet diameter, reduce the suction piping lenght and the number of the bends, decrea-
se the speed of the pump and the temperature of the medium, check that the increase (caused by the decreasing
temperature) is suitable to the motor power
Increase the head, the piping inlet diameter, reduce the suction piping lenght and the number of the bends, decrea-
se the speed of the pump and the temperature of the medium, check that the increase (caused by the decreasing
temperature) is suitable to the motor power
Check and tighten suction piping connections, tighten the packing glands and, if necessary, replace them
Fill pumping case and feeding piping with liquid, expelling air
Increase medium level, lower suction opening position
Clean fi lters
Via Giovanni Falcone, 8 42048 Rubiera (RE) - Italy
E-mail:info@omacpompe.com SitoWeb:www.omacpompe.com
CHAPTER 5: B SERIES LDPU MAINTENANCE
REMEDIES:
REMEDIES:
REMEDIES:
O.M.A.C. s.r.l.
Tel.0522/629371 - 629923 Fax 0522/628980
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Chap.5 - pag.