Operating Troubles - OBL MB Series Operating Manual

Moä t soá söï coá xaû y ra khi vaä n haø n h
Löu löôï n g thaá p hôn theo yeâ u caà u
NGUYEÂ N NHAÂ N / CAUSES
Khoâ n g khí ñi vaø o oá n g huù t qua khôù p noá i :
Air enters the suction piping through the fittings:
Khoâ n g khí bò giöõ laï i trong bôm:
Air trapped inside the pump.
Chieà u saâ u huù t quaù lôù n
Excessive suction head lift:
AÙ p suaá t bay hôi cuû a dung dòch quaù cao
Vapour pressure of the liquid too high:
Nhieä t ñoä bôm cao:
Pumping temperatures too high.
Ñoä nhôù t dung dòch cao
Viscosity of the liquid too high.
Thuø n g chöù a kín khít hoaë c khoâ n g coù loã thoâ n g hôi
Feed tank hermetically sealed and with no vent:
Ñöôø n g oá n g huù t bò taé c hoaë c van ñoù n g
Suction piping clogged or valves shut
Boä loï c ñaà u huù t taé c
Filter on suction side clogged:
Van cuû a bôm keï t vì chaá t baå n
Pump valves jammed because of dirt:
Van an toaø n caø i ñaë t aù p suaá t quaù thaá p
Safety valve setting pressure too low:
Löu löôï n g khoâ n g ñuù n g hoaë c cao hôn yeâ u caà u
NGUYEÂ N NHAÂ N / CAUSES
AÙ p suaá t ñaà u huù t cao hôn aù p suaá t ñaà u ñaå y :
Suction pressure higher than discharge pressure:
Van taï o aù p löï c ngöôï c bò keï t taï i vò trí môû vì baå n hoaë c aù p
löï c caø i ñaë t quaù thaá p
Back pressure valve stuck in open position because of dirt
or setting pressure too low:
Van cuû a bôm bò keï t ôû vò trí môû
Pump valves jammed in open position:
Thaâ n bôm vaø ñoä n g cô quaù noù n g
NGUYEÂ N NHAÂ N / CAUSES
Laé p ñieä n sai
Incorrect wiring:
Bôm laø m vieä c ôû aù p löï c cao hôn aù p löï c cho pheù p
Overheating due to pump working pressure higher than allowed:
AÙ p suaá t cao hôn quy ñònh
Pressures higher than allowed:
Maë t bích bôm bò neù n quaù chaë t
Stresses on pump flanges:
Ñöôø n g oá n g ñaå y taé c hoaë c van bò ñoù n g
Discharge pipeline clogged or valve shut:
Van taï o aù p löï c ngöôï c caø i ñaë t aù p suaá t cao hôn yeâ u caà u cho pheù p
Back pressure valve set to a pressure higher than allowed:
Möù c daà u trong hoä p soá thaá p
Oil level in the gearbox is low:

Operating troubles

Flow rate lower than expected
CAÙ C H KHAÉ C PHUÏ C / SOLUTIONS
Kieå m tra.
Check.
Cho bôm chaï y vôù i löu löôï n g toá i ña trong thôø i gian ngaé n .
For a short while, keep flow rate to maximum.
Giaû m xuoá n g
Reduce it.
Taê n g aù p suaá t thuyû tónh ôû ñaà u huù t cuû a bôm
Increase hydrostatic head on suction side
Taê n g aù p suaá t thuyû tónh ôû ñaà u huù t cuû a bôm
Increase hydrostatic head on suction side
Laé p ñaë t ñöôø n g oá n g huù t coù ñöôø n g kính lôù n . Taê n g aù p suaá t thuyû
tính ñaà u huù t .
Install a suction piping of larger diameter. Increase hydrostatic head on
suction side.
Laø m loã thoâ n g khí treâ n ñænh cuû a thuø n g chöù a
Make a vent in the tank upper part.
Kieå m tra.
Check.
Veä sinh
Clean it.
Thaù o van an toaø n caå n thaä n .
Dismantle the valves and clean them carefully.
Kieå m tra.
Check.
Flow rate irregular or higher than expected
CAÙ C H KHAÉ C PHUÏ C / SOLUTIONS
Taê n g aù p suaá t ñaà u ñaå y thaá p hôn so vôù i ñaà u huù t 0,3÷0,5 Kg/cm
Increase the discharge head of at least 0,3÷0,5 Kg/cmq (3÷5m)
respect to the suction pressure.
Kieå m tra.
Check.
Kieå m tra.
Check.
Overheating of pump body and motor
CAÙ C H KHAÉ C PHUÏ C / SOLUTIONS
Kieå m tra.
Check.
Kieå m tra aù p löï c lôù n nhaá t taï i ñaà u ñaå y baè n g ñoà n g hoà ño aù p löï c
Check max. discharge pressure by means of a pressure gauge fitted on the discharge pipeline.
(Xem aù p suaá t lôù n nhaá t ghi treâ n thaâ n bôm) giaû m aù p suaá t ñaà u
ñaå y hoaë c laé p thieá t bò tieâ u xung ôû ñaà u oá n g ñaå y
(see max. pressure indicated on pump rating plate) reduce the discharge pressure
or install a dampener in case of excessive narrowing on the discharge pipeline.
Nôù i loû n g oá n g noá i vôù i ñaà u bôm vaø kieå m tra
Loosen the pipes connected to the pumphead and check.
Kieå m tra.
Check.
Kieå m tra.
Check.
Cho theâ m daà u vaø o (xem baû n g F trg 9)
Add suitable oil. See table F, page 9.
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