33

Performance curves Low-NPSH pumpsCR 10, CRI 10, CRN 10

TM0

2 83

80 2

00

4 C

R 1

0

0 5 10 15 20 25 30 35 40 45 50 55 60 Q [US GPM]

0

50

100

150

200

250

300

350

400

450

500

550

600

650

700

750

800

[ft]H

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Q [m³/h]

0

20

40

60

80

100

120

140

160

180

200

220

240

[m]H

0

50

100

150

200

250

300

350

400

450

500

550

600

650

700

750

800

[ft]H

CR 10

2-pole, 60 Hz

CRI 10

CRN 10

-17

-16

-14

-12

-10

-9

-8

-7

-6

-5

-4

-3

0 5 10 15 20 25 30 35 40 45 50 55 60 Q [US GPM]

0.0

0.2

0.4

0.6

0.8[hp]P2

0

20

40

60

80

Eff[%]

0.0

0.2

0.4

[kW]P2

P2Eff

0 5 10 15 20 25 30 35 40 45 50 55 60 Q [US GPM]

0

5

10

15

[ft]NPSH

0

5

10

15

[ft]NPSH

0

2

4

[m]H

Low NPSHR

NPSHR

23

How to read the curve charts

Fig. 27 How to read the curve charts

Guidelines to performance curvesThe guidelines below apply to the curves shown on thefollowing pages:

1. The motors used for the measurements are standard motors (ODP, TEFC or MLE).

2. Measurements have been made with airless water at a temperature of 68°F.

3. The curves apply to a kinematic viscosity ofυ = 1 mm2/s (1 cSt).

4. Due to the risk of overheating, the pumps shouldnot be used at a flow below the minimum flow rate.

5. The QH curves apply to actual speed with the motor types mentioned at 60 Hz.

The curve below shows the minimum flow rate as apercentage of the nominal flow rate in relation to theliquid temperature. The dotted line shows a CR pumpfitted with an air-cooled top assembly.

Fig. 28 Minimum flow rate

TM0

2 0

039

130

3

0 20 40 60 80 100 120 140 160 180 200 Q [US GPM]

0

50

100

150

200

250

300

350

400

450

500

550

600

650

700

750

800

850

900

950

1000[ft]H

0

50

100

150

200

250

300

350

400

450

500

550

600

650

700

750

800

850

900

950

1000[ft]H

0

20

40

60

80

100

120

140

160

180

200

220

240

260

280

300

[m]H

0 5 10 15 20 25 30 35 40 45 Q [m³/h]

CR(E) 32

2-pole, 60 Hz

CRN(E) 32 -11-2

-10

-1 (E) -1-1 (E)

-10-2

-2 (E) -2-1 -2-2

-3

-3-2 (E)

-4

-4-2

-5

-5-2

-6

-6-2

-7

-7-2

-8

-8-2

-9

-9-2

0 20 40 60 80 100 120 140 160 180 200 Q [US GPM]

0

1

2

3

4

P2[hp]

0

20

40

60

80[%]Eff

0

1

2

P2[kW]

P2 1/1

P2 2/3

Eff

0 20 40 60 80 100 120 140 160 180 200 Q [US GPM]

0

10

20

30

NPSH[ft]

0

10

20

30[ft]H

0

4

8

[m]H

NPSHR

Number of stages.First figure: number of stages; second figure: number of reduced-diameter impellers.

The power curves indicatepump input power per stage.Curves are shown for complete(1/1) and for reduced-diameter(2/3) impellers.

Pump type, number of polesand frequency.

QH curve for the individual pump.The bold curves indicate the recom-mended performance range for best efficiency.

The eff curve shows the efficiency of the pump. The eff curve is an average curve of all the pump types shown in the chart.The efficiency of pumps with reduced-diameter impellers is approx. 2% lower than the eff curve shown in the chart.

The NPSHR curve is an averagecurve for all the variants shown.When sizing the pumps, add asafety margin of at least 2.0 feet.

TM0

2 75

38 3

703

40 60 80 120 140 160 180 t [°F]

0

10

20

30

Qmin[%]

140 176 212 248 284 320 356104

Selection and sizing Vertical multistage centrifugal pumps

CrCriCrn.book Page 23 Monday, November 15, 2004 11:32 AM

13

Vertical multistage centrifugal pumpsConstruction

CR(E) 1s, 1, 3, 5, 10, 15 and 20

Sectional drawing

Materials: CR(E)

1) CR(E) 1s, 1, 3, 52) CR(E) 10, 15, 203) Stainless steel available on request.4) CF 8M is cast equivalent of AISI 316 stainless steel.5) CRI(E)/CRN(E) 1s, 1, 3, 56) CRN(E) 10, 15, 207) CRI(E) 10, 15, 20

CRI(E), CRN(E) 1s, 1, 3, 5, 10, 15 and 20

Sectional drawing

Materials: CRI(E), CRN(E)

TM0

2 11

98

06

01

- GR7

377

- GR

7379

TM0

2 11

94

140

3

Pos. Designation Materials AISI/ASTM

1 Pump head Cast iron A 48-30 B

3 Shaft Stainless steelAISI 316 1)

AISI 431 2)

4 Impeller Stainless steel AISI 304

5 Chamber Stainless steel AISI 304

6 Outer sleeve Stainless steel AISI 304

7O-ring for outer sleeve

EPDM or FKM

8 Base Cast iron A 48-30 B

9 Neck ring PTFE

10 Shaft seal Cartridge type

Bearing rings Silicon carbide

Rubber parts EPDM or FKM

1

3

10

4

5

9

8

67

TM0

2 18

08

200

1 - G

R73

73 -

GR

7375

TM0

2 11

95

140

3

Pos. Designation Materials AISI/ASTM

1 Pump head Cast iron 3) A 48-30 B

2 Pump head cover Stainless steel CF 8M 4)

3 Shaft Stainless steelAISI 316 5)

AISI 329 6)

AISI 431 7)

8 Base Stainless steel CF 8M4)

9 Neck ring PTFE

10 Shaft seal Cartridge type

11 Base plate Cast iron 3) A 48-30 B

Bearing rings Silicon carbide

Rubber parts EPDM or FKM

CRI(E)

4 Impeller Stainless steel AISI 304

5 Chamber Stainless steel AISI 304

6 Outer sleeve Stainless steel AISI 304

7 O-ring for outer sleeve EPDM or FKM

CRN(E)

4 Impeller Stainless steel AISI 316

5 Chamber Stainless steel AISI 316

6 Outer sleeve Stainless steel AISI 316

7 O-ring for outer sleeve EPDM or FKM

1

2 10

4

5

9

8

6

3

11

7

CrCriCrn.book Page 13 Monday, November 15, 2004 11:32 AM