Sound Pressure Level; Required Npsh Values - KRAL L Series Operating Instructions Manual

4 Technical data

4.2 Sound pressure level

4.2 Sound pressure level

4.3 Required NPSH values

Size Viscosity
2
[mm /s]
5 6
37
152
380
7.5 6
37
152
380
10 6
37
152
380
15 6
37
152
380
20 6
37
152
380
26 6
37
152
380
12
Guide values at 1 m distance, 1450 min
Pump
Motor
Pump unit
Tab. 4: Sound pressure level
The following table lists the required NPSH values during operation with a low-volatile pumped liquid
such as lubricating oil or hydraulic liquid. When pumped liquids have a readily volatile component con-
tent, the required NPSH values increase notably:
o Fuel oil requires an NPSH value of at least 6 mWC.
o In the case of liquids that contain water (for example heavy fuel oil) the values in the table have to
be increased by the vapour pressure of the water at the specified operating temperature.
The required NPSH values also need to be increased if there are gas contents, regardless of whether
they are dissolved or not. In case of any doubt, please contact the manufacturer.
NPSH values [mWC] at speed
-1
[min ]
1450 1750 2900
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0 2.3
2.0 2.1
2.0
2.0
2.0 2.3
2.0
2.0
2.0
2.0 2.6
2.0
2.0
2.0 2.4
2.1 2.3 3.1
2.0 2.2
2.0 2.2
2.0 2.9
2.3 2.6 3.9
Tab. 5: Required NPSH values
OIL 02en-GB Edition 2019-03
-1
, 20 bar
Size
5 – 54
Max. sound pressure level ±3 [dB(A)]
58.0
62.0
63.5
Size Viscosity
3500 [mm
32 6
37
152
380
42 6
37
152
2.5 380
2.0 54 6
37
2.3 152
2.5 380
55 6
37
2.2 152
2.9 380
2.1 74 6
2.1 37
2.8 152
3.7 380
2.7 85 6
2.7 37
3.5 152
4.8 380
55 – 84
59.0
62.0
64.0
NPSH values [mWC] at speed
-1
[min ]
2
/s] 1450 1750
2.0
2.0
2.0
2.1 2.2
2.0
2.0
2.0
2.3 2.6
2.0 2.1
2.0 2.3
2.5 2.7
2.9 3.2
2.0
2.0
2.0
2.2 2.4
2.0
2.0
2.0 2.1
2.5 2.8
2.0
2.0 2.3
2.6 3.0
Operating instructions
2900 3500
2.3 2.7
3.0 3.5
2.2 2.7
2.2 2.7
2.9 3.5
3.9 4.8
3.0 3.7
3.4 4.2
4.1 5.1
5.0 6.3
2.3
2.3
2.6 3.1
3.4 4.1
2.5 3.1
2.5 3.0
3.3 4.1
4.4 5.6
2.8 3.4
3.1 3.8
3.7 4.7
5.0 6.5