Torishima Pump MMO - Mechanical Seal; General Caution

Part No. Part Designation Part No. Part Designation Part No. Part Designation
1060 Suction casing 4120.2 O-ring 9021 Gland bolt
1070 Discharge casing 4520 Stuffing box gland 9050 Tie bolt
1080 Stage casing 4580 Lantern ring 9200.1 Hex. nut
1711 Final stage diffuser 4610 Stuffing box packing 9200.2 Hex. nut
2100 Shaft 5040.1 Spacer ring 9201 Threaded plug
2300 Impeller 5040.2 Spacer ring 9320.1 Circlip
3210 Deep groove ball bearing 5070 Thrower 9320.2 Circlip
3500 Bearing housing 5240 Shaft protecting sleeve 9400.1 Key
3600 Bearing cover 5251.1 Spacer sleeve 9400.2 Key
3610 Bearing end cover 9010 Hex. head bolt 9400.3 Key
4120.1 0-ring 9020 Stud 9400.4 Key
4. Mechanical Seal
4. 1. General Caution
(1) The mechanical seal service life is significantly shortened by impurities if included therein. Therefore,
clean the mechanical seal and the pump internals when reassembling and prevent invasion of such
impurities into the mechanical seal from the flushing line during pump running.
(2) Absolutely avoid dry-running (including the running at seal chamber pressure less than the atmospheric
pressure). Dry-running would cause seizure and damage of the mechanical seal and occasional damage
of the pump.
(3) The sliding end face of the mechanical seal is finished very accurately by lapping. So, it must be handled
with good care neither to flaw nor break the sliding end face.
(4) Once overhauled, replace the sliding end face of the mechanical seal with new one or repair it by lapping
as a rule.
4. 2. Construction
Fig. 7 Illustrates the mechanical seal construction. Fig. 7 Construction of Mechanical Seal