KSB RDL - Page 13

RDL
12
Fig.6 – Peripheral Speed Fig.7 – Liquid flow of external source
size curve size curve size curve size curve size curve
125-140 1 150-430 1 250-500 3 400-440 3 600-620 2
125-170 1 150-500 2 250-620 3 400-480 3 600-710 3
125-200 1 200-280 2 300-280 3 400-540 4 600-830 3
125-250 1 200-340 2 300-340 3 400-620 4 700-590 3
125-310 1 200-400 2 300-400 3 500-510 2 700-710 3
150-250 1 200-500 2 300-500 3 500-640 3 700-820 3
150-280 1 200-620 2 300-620 3 500-700 3 800-740 2
150-310 1 250-280 2 350-500 3 500-790 3 800-840 2
150-340 1 250-340 2 350-620 3 500-890 4 800-970 3
150-400 1 250-400 2 400-390 3 600-540 2
∆p = P – ps where: P = pressure of external source liquid (bar)
ps = suction pressure (bar)
4.4.5 Packing rings
Usually shaft sealing is done with packing rings. Position of neck ring, packing rings and lantern ring are shown on fig. 8.
Dimensions of seal chamber, packing rings are mentioned on table 1. The lantern ring, disposed between packing rings
receives the liquid from the region of pump high pressure. Lantern ring makes the distribution of liquid which lubricates the
packing and avoid the entrance of air in the pump. Liquid flow to the lantern ring is controlled by a valve installed in the pump
external piping.
Code Description
0
Sealing by liquid being pumped
0-1 with external piping
0-2 with external piping + filter
•
1
1-1 Sealing through clean liquid of
external source
9 Sealing with mechanical seal (2 seals)
Fig.8 – Shaft sealing • When pumped liquid contains solid in suspension.
200
300
400
500
600
700
800
900
1000
500 1000 1500 2000 2500 3000 3500 4000
rpm
Impeller diameter (mm)
Peripheral speed=40m/s Peripheral speed=60m/s
Peripheral speed
limit for impeller in:
A536 60-40-18
CuSn10-C-GS
A743 CA6NM
A743 CF8M
0
1
2
3
4
5
0 50 100 150 200 250 300 350
Q (l/h)
P (bar)
1
2
3
4