Desmi ESLH/-17, Operation And Maintenance Instructions, Page: 14 / 19

_______________________________________________________________________________
DESMI Pumping Technology A/S
14
www.desmi.com
Tagholm 1
9400 Nørresundby
– Denmark
Tel: +45 96 32 81 11 Fax: +45 98 17 54 99
E-mail:
desmi@desmi.com
11.
INSPECTION AND MAINTENANCE
Inspect the shaft seal for leaks at regular intervals.
- Before inspection of a pump without guard check that the pump cannot be started
unintentionally.
- The system is to be without pressure and drained of liquid.
- The repairman must be familiar with the type of liquid which has been pumped as well
as the safety measures he is to take when handling the liquid.
On pumps inoperative, the shaft must be rotated at least 2-3 rounds monthly to avoid
standstill damage to shaft seal and bearings. If the pump is liquid-filled, it can alternatively be
started up briefly.
In special applications, more frequent rotation or short-term start-up may be necessary to
avoid solidification of the impeller and/or shaft seal.
In pressurized systems, the shaft seal is often seen to leak slightly during standstill
– in most
cases the leak stops shortly after the pump is started up.
11.1
DRAINING THE PUMP
When the piping system has been drained, note that there is still liquid in the pump. Remove
the liquid by dismantling the pipe plug (2) at the bottom of the pump and shaft seal chamber.
12. REPAIRS
12.1
ORDERING SPARE PARTS
When ordering spare parts please always state pump type, serial No. (appears on the name
plate of the pump), position No. on the assembly drawing and designation on the spare parts
list.
The following parts are exposed to wear: Shaft seal (10), impeller (5), carbon bearing (4), O-
rings (3 and 27), oil seal ring (11) and the ball bearing (13).
12.2
REPLACING THE IMPELLER
Close the valves on both sides of the pump. Draining the pump by dismantling pipe plug (2)
at the bottom of the pump and shaft seal chamber. And dismantle the motor, Loosen the nuts
(22) , set screws (37) and dismantle the rear cover with rotating parts from the pump casing.
Remove the camp cap nut (24) and take off the impeller (5). Fit the new impeller.
12.3 REPLACING O-RINGS
When impeller and shaft have been separated, Remove the key (19) and loosen the nuts (18)
and dismantle the bearing house with shaft and ball bearing unit from the rear cover. The O-
ring (3 and 21) in the rear cover (7) and bearing house can be pulled out.
In order to replace the O-ring (21) it is necessary first to dismantle the impeller.
12.4
REPLACING SHAFT SEAL (22)
Dismantling as described in paragraph 5.
When the impeller has been dismantled, Remove the key (19) and loosen the nuts (18) and
dismantle the bearing house with shaft and ball bearing unit from the rear cover. Loosen the