Unibloc-Pump 54001010P20H6010T12E, Operation & Service Manual

UNIBLOC-PD Operation & Service Manual: PD200-576  29

4.4.8 UNIBLOC 501 Series Seal Installation – Final Step

See section 5.3 for torque limits.  If not part of the shaft seal as-

sembly, slide the plastic mounting sleeves over the splined ends 

of the shafts.  Slide on the rotor housing (1) tap it with a rubber 

mallet to seat it properly on the dowel pins (20).  Make sure the 

alignment mark on the rotor housing lines up with the one on the 

gearbox (6). The rotor housing must make firm contact with the 

gearbox.  Fasten the hex nuts (43) with the split washer (44) on 

the stud ends and tighten in a cross pattern.  Remove the plastic 

sleeves from the shaft ends. Slide the rotor shaft o-rings (27) 

over the splined shaft ends and on the step, if applicable.  One 

rotor and one shaft have been marked with the same symbol.  

Slide the rotors over the corresponding shafts and push them 

making sure the o-rings seat properly. The rotors must make 

contact with the shafts.  Place o-rings (26) on the rotor bolts 

(14a,14b).  Lubricate them and the rotor bores.  Place a nonmet-

al object between the rotors to keep them from turning.  Thread 

the rotor bolts into the shaft ends. Turn the drive shaft to make 

sure the rotors turn freely. Measure the clearances between the 

rotor housing and the rotors. Compare these values with those 

listed in section 5.4.  If the measured clearances at positions 1-7, 

8, and 10 are smaller than those listed, the rotors must be ground 

and polished to achieve the correct values.  If the measured 

clearances at positions 9 and 11 are not within the tolerances 

listed the shafts must be adjusted by disassembling the gearbox, 

as instructed in section 3.0, and changing the shims (11a).

Place the front cover (2) and the o-ring (28) on the studs.  Tight-

en the front cover nuts (16).  Check the oil level in the gearbox 

as described in section 5.2.  The pump is now ready to be in-

stalled in the system. Refer to section 2.3 before starting the 

pump.

4.5 Pump Bearing Housing Service

The 

UNIBLOC

 bearing housing is supplied permanently lubricated with nitrile seals. However, for certain applications and at the 

user’s request, drain plugs and a vent will be supplied. The oil level should be checked at regular intervals and the seals should be 

changed once per year or after 2000 hours of service, whichever occurs first. When applications exceed constant service temper

-

atures of 1800C (3560F) a vent and high temperature lubricant must be used. For such cases, contact 

UNIBLOC-PUMP

 or an 

authorized service center for an adequate service schedule.  

Before proceeding with the following steps, 

DISENGAGE POWER TO THE MOTOR

.  If the pump is connected to piping, 

depressurize the system and close valves on both the suction and discharge sides to isolate the pump from the rest of the system.  

Disconnect the piping and remove the pump from the system. Removal of the wet end of the pump (i.e. the  cover,  rotors,  rotor 

housing, and shaft seals) must be completed first before disassembly of the pump bearing housing. The method of removing these 

parts is dependent upon the type of shaft seals the pump has and is outlined in section 4.4.