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Lowara ESHE 32-250/07/X45RSNA [111/120] Technical appendix
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111
TECHNICAL APPENDIX
The minimum operating values that can be reached at the
pump suction end are limited by the onset of cavitation.
Cavitation is the formation of vapour-filled cavities within
liquids where the pressure is locally reduced to a critical value,
or where the local pressure is equal to, or just below the
vapour pressure of the liquid.
The vapour-filled cavities flow with the current and
when they reach a higher pressure area the vapour
contained in the cavities condenses. The cavities collide,
generating pressure waves that are transmitted to the
walls. These, being subjected to stress cycles, gradually
become deformed and yield due to fatigue. This
phenomenon, characterized by a metallic noise
produced by the hammering on the pipe walls, is called
incipient cavitation.
The damage caused by cavitation may be magnified by
electrochemical corrosion and a local rise in
temperature due to the plastic deformation of the
walls. The materials that offer the highest resistance to
heat and corrosion are alloy steels, especially austenitic
steel. The conditions that trigger cavitation may be
assessed by calculating the total net suction head,
referred to in technical literature with the acronym
NPSH (Net Positive Suction Head).
The NPSH represents the total energy (expressed in m.)
of the liquid measured at suction under conditions of
incipient cavitation, excluding the vapour pressure
(expressed in m.) that the liquid has at the pump inlet.
To find the static height hz at which to install the
machine under safe conditions, the following formula
must be verified:
hp + hz ≥ (NPSHr + 0.5) + hf + hpv
where:
hp is the absolute pressure applied to the free liquid
surface in the suction tank, expressed in m. of
liquid; hp is the quotient between the barometric
pressure and the specific weight of the liquid.
hz is the suction lift between the pump axis and the
free liquid surface in the suction tank, expressed
in m.; hz is negative when the liquid level is
lower than the pump axis.
hf is the flow resistance in the suction line and its
accessories, such as: fittings, foot valve, gate
valve, elbows, etc.
hpv is the vapour pressure of the liquid at the
operating temperature, expressed in m. of
liquid. hpv is the quotient between the Pv vapour
pressure and the liquid’s specific weight.
0,5 is the safety factor.
The maximum possible suction head for installation
depends on the value of the atmospheric pressure
(i.e. the elevation above sea level at which the pump
is installed) and the temperature of the liquid.
To help the user, with reference to water temperature
(4° C) and to the elevation above sea level, the
following tables show the drop in hydraulic pressure
head in relation to the elevation above sea level, and
the suction loss in relation to temperature.
Friction loss is shown in the tables Flow Resistance of
this catalogue. To reduce it to a minimum, especially
in cases of high suction head (over 4-5 m.) or within
the operating limits with high flow rates, we
recommend using a suction line having a larger
diameter than that of the pump’s suction port.
It is always a good idea to position the pump as close
as possible to the liquid to be pumped.
Make the following calculation:
Liquid: water at ~15°C γ = 1 kg/dm
3
Flow rate required: 25 m
3
/h
Head for required delivery: 70 m.
Suction lift: 3,5 m.
The selection is an 33SV3G075T pump whose NPSH
required value is, at 25 m
3
/h, of 2 m.
For water at 15 °C
hp = Pa / γ = 10,33m, hpv = Pv / γ = 0,174m (0,01701 bar)
The Hf flow resistance in the suction line with foot
valves is ~ 1,2 m.
By substituting the parameters in formula with the
numeric values above, we have:
10,33 + (-3,5) ≥ (2 + 0,5) + 1,2 + 0,17
from which we have: 6,8 > 3,9
The relation is therefore verified.
Water
temperature (°C) 20 40 60 80 90 110 120
Suction
loss (m) 0,2 0,7 2,0 5,0 7,4 15,4 21,5
Elevation above
sea level (m) 500 1000 1500 2000 2500 3000
Suction
loss (m) 0,55 1,1 1,65 2,2 2,75 3,3
NPSH
1
1
Содержание
- E sh series 1
- Erp 2009 125 ec 1
- Ecodesign directive erp 2
- Contents 3
- 40 25 80 65 50 4
- A0046_b_ch 4
- A0047_b_ch 4
- E sh series hydraulic performance range at 50 hz 2 poles 4
- Esh 1450 rpm iso 9906 2012 grade 3b 4
- Esh 2900 rpm iso 9906 2012 grade 3b 4
- Hydraulic performance range at 50 hz 4 poles 4
- Q imp gpm 4
- Q us gpm 4
- E sh series general introduction 5
- E sh series commercial building services cbs applications benefits 6
- E sh series for industry applications benefits 7
- E s h f 6 5 1 6 0 1 1 0 a p 2 5 v s n a 8
- Esh series identification code 8
- Esh pump only eshf electric pump 9
- Esh series rating plate 9
- Eshe eshs electric pump 9
- Legend 9
- Esh series 10
- List of models at 50 hz 2 poles 10
- Esh series 11
- List of models at 50 hz 4 poles 11
- Denominazione modelli denominazione modelli denominazione modelli denominazione modelli serie she she4 con serie she she4 con serie she she4 con serie she she4 con staffa di sostegno staffa di sostegno staffa di sostegno staffa di sostegno 12
- Eshe series electric pump cross section and main components 12
- Denominazione modelli serie eshe con piede di sostegno sul motore 13
- Denominazione modelli serie she4 con motore mec 71 b5 13
- Eshe series electric pump cross section and main components 13
- Denominazione modelli denominazione modelli denominazione modelli denominazione modelli serie eshs eshs4 con serie eshs eshs4 con serie eshs eshs4 con serie eshs eshs4 con staffa di sostegno staffa di sostegno staffa di sostegno staffa di sostegno 14
- Eshs series electric pump cross section and main components 14
- Denominazione modelli serie eshs con piede di sostegno sul motore 15
- Eshs series electric pump cross section and main components 15
- Denominazione modelli serie eshf 16
- Esh eshf eshc series electric pump cross section and main components 16
- Esh series mechanical seal 17
- Hot water minimum pressure required at mechanical seal hot water could be different in case of other liquids 17
- Pressure temperature application limits for complete pump 17
- Standard version version with fixed assembly anti rotation 17
- Erp 2009 125 ec 18
- Esh series motors 18
- Eshe series single phase motors at 50 hz 2 poles 18
- Motori monofase per serie she 50 hz 2 poli motori monofase per serie she 50 hz 2 poli motori monofase per serie she 50 hz 2 poli motori monofase per serie she 50 hz 2 poli 18
- Eshe series three phase motors at 50 hz 2 poles 19
- Motori trifase per serie eshe 50 hz 2 poli 19
- Eshs series three phase motors at 50 hz 2 poles up to 22 kw 20
- Motori trifase per serie eshs 50 hz 2 poli motori trifase per serie eshs 50 hz 2 poli motori trifase per serie eshs 50 hz 2 poli motori trifase per serie eshs 50 hz 2 poli 20
- Eshf eshc series three phase motors at 50 hz 2 poles up to 18 5 kw 21
- Motori trifase per serie shf 50 hz 2 poli fino a 18 5 kw motori trifase per serie shf 50 hz 2 poli fino a 18 5 kw motori trifase per serie shf 50 hz 2 poli fino a 18 5 kw motori trifase per serie shf 50 hz 2 poli fino a 18 5 kw 21
- Eshs series b35 from 30 to 37 kw eshf series b3 from 22 to 75 kw three phase motors at 50 hz 2 poles 22
- Motori trifase per serie shs shf 50 hz 2 poli da 22kw fino a75kw motori trifase per serie shs shf 50 hz 2 poli da 22kw fino a75kw motori trifase per serie shs shf 50 hz 2 poli da 22kw fino a75kw motori trifase per serie shs shf 50 hz 2 poli da 22kw fino a75kw 22
- Eshe series three phase motors at 50 hz 4 poles 23
- Motori trifase per serie she 50 hz 4 poli motori trifase per serie she 50 hz 4 poli motori trifase per serie she 50 hz 4 poli motori trifase per serie she 50 hz 4 poli 23
- Eshs series b5 b35 from 0 55 to 11 kw eshf series b3 from 0 25 to 11 kw three phase motors at 50 hz 4 poles 24
- Motori trifase per serie eshs4 eshf4 50 hz 4 poli fino a 11 kw motori trifase per serie eshs4 eshf4 50 hz 4 poli fino a 11 kw motori trifase per serie eshs4 eshf4 50 hz 4 poli fino a 11 kw motori trifase per serie eshs4 eshf4 50 hz 4 poli fino a 11 kw 24
- Eshe eshs motors 2 poles 50 hz eshf eshc motors 2 poles 50 hz 25
- Eshs eshf motors 4 poles 50 hz eshe motors 4 poles 50 hz 25
- Motor noise 25
- The tables below show the mean sound pressure levels lp measured at 1 meter s distance in a free field according to the a curve iso 1680 standard the noise values are measured with idling 50 hz motor with a tolerance of 3 db a 25
- Erp 2009 125 ec 26
- Esh series pumps 26
- Esh series minimum efficiency index mei 27
- 2900 rpm iso 9906 2012 grade 3b esh 28
- Esh series hydraulic performance range at 50 hz 2 poles 28
- Esh 25 32 40 50 series hydraulic performance table at 50 hz 2 poles 29
- Esh 65 80 series hydraulic performance table at 50 hz 2 poles 30
- 1450 rpm iso 9906 2012 grade 3b esh 31
- Esh series hydraulic performance range at 50 hz 4 poles 31
- Esh 25 32 40 50 series hydraulic performance range at 50 hz 4 poles 32
- Esh 65 80 series hydraulic performance range at 50 hz 4 poles 33
- Esh series identification of impeller typology 34
- Max efficiency η 34
- Esh 25 125 2900 rpm iso 9906 2012 grade 3b 35
- Esh series operating characteristics at 50 hz 2 poles 35
- Esh 25 160 2900 rpm iso 9906 2012 grade 3b 36
- Esh series operating characteristics at 50 hz 2 poles 36
- Esh 25 200 2900 rpm iso 9906 2012 grade 3b 37
- Esh series operating characteristics at 50 hz 2 poles 37
- Esh 25 250 2900 rpm iso 9906 2012 grade 3b 38
- Esh series operating characteristics at 50 hz 2 poles 38
- Esh 32 125 2900 rpm iso 9906 2012 grade 3b 39
- Esh series operating characteristics at 50 hz 2 poles 39
- Esh 32 160 2900 rpm iso 9906 2012 grade 3b 40
- Esh series operating characteristics at 50 hz 2 poles 40
- Esh 32 200 2900 rpm iso 9906 2012 grade 3b 41
- Esh series operating characteristics at 50 hz 2 poles 41
- Esh 32 250 2900 rpm iso 9906 2012 grade 3b 42
- Esh series operating characteristics at 50 hz 2 poles 42
- Esh 40 125 2900 rpm iso 9906 2012 grade 3b 43
- Esh series operating characteristics at 50 hz 2 poles 43
- Esh 40 160 2900 rpm iso 9906 2012 grade 3b 44
- Esh series operating characteristics at 50 hz 2 poles 44
- Esh 40 200 2900 rpm iso 9906 2012 grade 3b 45
- Esh series operating characteristics at 50 hz 2 poles 45
- Esh 40 250 2900 rpm iso 9906 2012 grade 3b 46
- Esh series operating characteristics at 50 hz 2 poles 46
- Esh 50 125 2900 rpm iso 9906 2012 grade 3b 47
- Esh series operating characteristics at 50 hz 2 poles 47
- Esh 50 160 2900 rpm iso 9906 2012 grade 3b 48
- Esh series operating characteristics at 50 hz 2 poles 48
- Esh 50 200 2900 rpm iso 9906 2012 grade 3b 49
- Esh series operating characteristics at 50 hz 2 poles 49
- Esh 50 250 2900 rpm iso 9906 2012 grade 3b 50
- Esh series operating characteristics at 50 hz 2 poles 50
- Esh 65 160 2900 rpm iso 9906 2012 grade 3b 51
- Esh series operating characteristics at 50 hz 2 poles 51
- Esh 65 200 2900 rpm iso 9906 2012 grade 3b 52
- Esh series operating characteristics at 50 hz 2 poles 52
- Esh 65 250 2900 rpm iso 9906 2012 grade 3b 53
- Esh series operating characteristics at 50 hz 2 poles 53
- Esh 80 160 2900 rpm iso 9906 2012 grade 3b 54
- Esh series operating characteristics at 50 hz 2 poles 54
- Esh 80 200 2900 rpm iso 9906 2012 grade 3b 55
- Esh series operating characteristics at 50 hz 2 poles 55
- Esh 80 250 2900 rpm iso 9906 2012 grade 3b 56
- Esh series operating characteristics at 50 hz 2 poles 56
- Esh 25 125 1450 rpm iso 9906 2012 grade 3b 57
- Esh series operating characteristics at 50 hz 4 poles 57
- Esh 25 160 1450 rpm iso 9906 2012 grade 3b 58
- Esh series operating characteristics at 50 hz 4 poles 58
- Esh 25 200 1450 rpm iso 9906 2012 grade 3b 59
- Esh series operating characteristics at 50 hz 4 poles 59
- Esh 25 250 1450 rpm iso 9906 2012 grade 3b 60
- Esh series operating characteristics at 50 hz 4 poles 60
- Esh 32 125 1450 rpm iso 9906 2012 grade 3b 61
- Esh series operating characteristics at 50 hz 4 poles 61
- Esh 32 160 1450 rpm iso 9906 2012 grade 3b 62
- Esh series operating characteristics at 50 hz 4 poles 62
- Esh 32 200 1450 rpm iso 9906 2012 grade 3b 63
- Esh series operating characteristics at 50 hz 4 poles 63
- Esh 32 250 1450 rpm iso 9906 2012 grade 3b 64
- Esh series operating characteristics at 50 hz 4 poles 64
- Esh 40 125 1450 rpm iso 9906 2012 grade 3b 65
- Esh series operating characteristics at 50 hz 4 poles 65
- Esh 40 160 1450 rpm iso 9906 2012 grade 3b 66
- Esh series operating characteristics at 50 hz 4 poles 66
- Esh 40 200 1450 rpm iso 9906 2012 grade 3b 67
- Esh series operating characteristics at 50 hz 4 poles 67
- Esh 40 250 1450 rpm iso 9906 2012 grade 3b 68
- Esh series operating characteristics at 50 hz 4 poles 68
- Esh 50 125 1450 rpm iso 9906 2012 grade 3b 69
- Esh series operating characteristics at 50 hz 4 poles 69
- Esh 50 160 1450 rpm iso 9906 2012 grade 3b 70
- Esh series operating characteristics at 50 hz 4 poles 70
- Esh 50 200 1450 rpm iso 9906 2012 grade 3b 71
- Esh series operating characteristics at 50 hz 4 poles 71
- Esh 50 250 1450 rpm iso 9906 2012 grade 3b 72
- Esh series operating characteristics at 50 hz 4 poles 72
- Esh 65 160 1450 rpm iso 9906 2012 grade 3b 73
- Esh series operating characteristics at 50 hz 4 poles 73
- Esh 65 200 1450 rpm iso 9906 2012 grade 3b 74
- Esh series operating characteristics at 50 hz 4 poles 74
- Esh 65 250 1450 rpm iso 9906 2012 grade 3b 75
- Esh series operating characteristics at 50 hz 4 poles 75
- Esh 80 160 1450 rpm iso 9906 2012 grade 3b 76
- Esh series operating characteristics at 50 hz 4 poles 76
- Esh 80 200 1450 rpm iso 9906 2012 grade 3b 77
- Esh series operating characteristics at 50 hz 4 poles 77
- Esh 80 250 1450 rpm iso 9906 2012 grade 3b 78
- Esh series operating characteristics at 50 hz 4 poles 78
- Dimensioni e pesi serie eshe 2 poli 50 hz dimensioni e pesi serie eshe 2 poli 50 hz dimensioni e pesi serie eshe 2 poli 50 hz dimensioni e pesi serie eshe 2 poli 50 hz 81
- Eshe series dimensions and weights at 50 hz 2 poles 81
- Dimensioni e pesi serie eshe 4 poli 50 hz dimensioni e pesi serie eshe 4 poli 50 hz dimensioni e pesi serie eshe 4 poli 50 hz dimensioni e pesi serie eshe 4 poli 50 hz 83
- Eshe series dimensions and weights at 50 hz 4 poles 83
- Dimensioni e pesi serie eshs 2 poli 50 hz dimensioni e pesi serie eshs 2 poli 50 hz dimensioni e pesi serie eshs 2 poli 50 hz dimensioni e pesi serie eshs 2 poli 50 hz 85
- Eshs series dimensions and weights at 50 hz 2 poles 85
- Dimensioni e pesi serie eshs 4 poli 50 hz dimensioni e pesi serie eshs 4 poli 50 hz dimensioni e pesi serie eshs 4 poli 50 hz dimensioni e pesi serie eshs 4 poli 50 hz 87
- Eshs series dimensions and weights at 50 hz 4 poles 87
- Dimensioni e pesi serie esh bare shaft dimensioni e pesi serie esh bare shaft dimensioni e pesi serie esh bare shaft dimensioni e pesi serie esh bare shaft 89
- Esh series dimensions and weights bare shaft 89
- Eshf series dimensions and weights at 50 hz 2 poles 91
- Dimensioni e pesi serie eshf 4 poli 50 hz dimensioni e pesi serie eshf 4 poli 50 hz dimensioni e pesi serie eshf 4 poli 50 hz dimensioni e pesi serie eshf 4 poli 50 hz 93
- Eshf series dimensions and weights at 50 hz 4 poles 93
- Eshc series dimensions and weights at 50 hz 2 poles 95
- Esh h series esh with hydrovar 97
- Esh h series esh with hydrovar 98
- Lowara 98
- Operating principle 98
- Typical example of energy savings 98
- Dimensions and weights 99
- H v l 4 0 7 5 a 0 0 1 0 99
- Hydrovar hvl identification code 99
- Hydrovar hvl emc compatibility 100
- Optional components 100
- Accessories 101
- Flexible coupling dimensions 102
- N b non atex version 102
- Shf dimensioni giunto elastico 102
- Dimensioni giunto elastico con spaziatore 103
- N b non atex version 103
- Spacer coupling dimensions 103
- Dimensioni controflange tonde 104
- Dimensioni controflange tonde f 104
- Esh series dimensions of 104
- Esh series dimensions of round weld counterflanges according to en 1092 1 104
- Round threaded counterflanges according to en 1092 1 104
- Dimensioni spessori per motori shf shs 105
- Dimensioni spessori pompa shf 105
- Esh series shim for motor feet 105
- Shim for pump feet eshf 105
- Reports and declarations 107
- Esh series typical applications 110
- Technical appendix 111
- Technical appendix 112
- Tensione di vapore tabella tensione di vapore ps e densita ρ dell acqua 112
- Vapour pressure vapour pressure ps and ρ density of water table 112
- Tabella perdite di carico per 100 m tubazione diritta in ghisa formula hazen williams c 100 113
- Table of flow resistance in 100 m of straight cast iron pipeline hazen williams formula c 100 113
- Technical appendix 113
- Flow resistance table of flow resistance in bends valves and gates 114
- Tabella lunghezza di tubazione equivalente 114
- Technical appendix 114
- The flow resistance is calculated using the equivalent pipeline length method according to the table below 114
- The table is valid for the hazen williams coefficient c 100 cast iron pipework for steel pipework multiply the values by 1 41 for stainless steel copper and coated cast iron pipework multiply the values by 1 85 when the equivalent pipeline length has been determined the flow resistance is obtained from the table of flow resistance the values given are guideline values which are bound to vary slightly according to the model especially for gate valves and non return valves for which it is a good idea to check the values supplied by manufacturers 114
- Length 115
- Pressure and head 115
- Technical appendix 115
- Temperature 115
- Volume 115
- Volumetric capacity 115
- Further product selection and documentation xylec 116
- Technical appendix 116
- Further product selection and documentation xylec 117
- Technical appendix 117
- Xylem zīl m 120
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