Self-Priming Centrifugal Pump


Self-Priming Centrifugal Pump
UHN series
(PAT.)

Outstanding self-priming performance even under extreme conditions

Top page
& Site map
Contact us


Technical data

Installation and piping


To make the best use of the features of the UHN type, please follow the items below.

1.

The pump sucks water in the axial direction. Be sure to install an inverse U-bent pipe in the suction piping as shown in the figure below.

2.

The pump, being a self-priming type, does not require installation of a foot valve or an intermediate valve in ordinary operating conditions. However, if frequent operation or shorter self-priming time is desired, we recommend installing such valves. The purpose is to keep as much water as possible in the pump. The valve need not function perfectly and minor leakage will not affect performance.

3.

If a gland packing is used for shaft sealing, we recommend installation of an external flusher to prevent air from being sucked during self-priming and to maintain efficiency of the gland packing.

4.

When the pump is started up, the water inside the casing is discharged once into the discharge side before returning to the casing, and then stabilizes after recirculation begins. If the discharged water floods the check valve and the bent pipe, the amount of recirculating water becomes insufficient and self-priming efficiency decreases. Therefore, be sure to install a riser of the height shown in the figure below. For situations where the riser is too long for installation, we can provide a short discharge pipe (h2) which is made of the same material as the casing and has a special construction. Please contact us for more details.

5.

Be sure to install a check valve on the discharge side of the pump. We recommend the YOKOTA Non-Water Hammer Check Valve to prevent water hammer due to reverse flow when pump operation is stopped. Particularly with parallel operation, when one pump is stopped, it will be subject to back pressure from the other pump, causing water hammer. The YOKOTA Non-Water Hammer Check Valve can prevent water hammer even in such a situation. Further, attachment of the YOKOTA No-Feed Detector (Optional) can prevent the pump from dry operation.

6.

If the pumps are under parallel operation or if the actual pump head above the check valve exceeds more than 1/3 of the shut off head, back pressure acts on the check valve, making it difficult to exhaust air. Install an exhaust valve to relieve such a situation. In this case, install a suitable socket (refer to the table below) on the riser at the highest possible position (refer to "J" in the figure below), and then install the exhaust valve so that the opening end of its suction part is in the center of the riser bore.
There may be water leakage from the exhaust valve. To prevent air from being sucked when operation is stopped, install a pipe from the exhaust valve to a point below the water level of the suction side.
For slurry liquid pumping, please contact us.



Piping layout example 1.
Self-priming suction operation

Attach the inverse U-bent pipe to the pump.

Self-Priming Centrifugal Pump / Self-priming suction operation

Limit the extension of the inverse U-bent pipe (L) within 3m.

Self-Priming Centrifugal Pump / Self-priming suction operation


Piping layout example 2.
Sealed tank (vacuum tank) extraction operation


Piping layout example 3.
Self-priming suction operation with long horizontal pipe

Attach the inverse U-bent pipe.

Self-Priming Centrifugal Pump / Sealed (vacuum) tank extraction operation
                  Operation

Self-Priming Centrifugal Pump / Self-priming suction operation with long horizontal pipe
                  horizontal pipe



Length of riser

Self-Priming Centrifugal Pump / Length of riser


Length of riser

h1 >= 200 + d + 5H (Total head of pump <= 50m)

h1 >= 300 + d + 5H (Total head of pump > 50m)

Where

h1:

Length of riser (mm)

d:

Discharge bore (mm)

H:

Total head of pump (m)

Example:
UHN-0520 50mm x 0.3m3/min x 22m x 1750rpm x 3.7kW
h
1 >= 200 + (50) + (5 x 22) = 360
Use a riser of over 360mm length, desirably over 500mm.
For slurry liquid pumping, please contact us.



Exhaust valve

Discharge pipe bore (mm)

Valve bore

40 - 80

10A

100-150

15A

200-250

20A




Flange

Self-Priming Centrifugal Pump / Flange


Unit: mm

Symbol
Flange dimensions (JIS 10K)
A (Bore)

40

50

65

80

100

125

150

200

250

D

140

155

175

185

210

250

280

330

400

C

105

120

140

150

175

210

240

290

355

n x h

4-19

4-19

4-19

8-19

8-19

8-23

8-23

12-23

12-25





Foundation bolt

Self-Priming Centrifugal Pump / Foundation bolt

Unit: mm

Bolt d
d1
S
L1
L
M12

12

32

50

250

M16

16

40

63

315

M20

20

50

80

400

M22

22

56

90

500




Motor frame number and output power (Enclosed fan-cooling type)

Unit : kW

Pole number
Frame number
2P
4P
6P

0.4

0.4

-

71

0.75

0.75

0.4

80

1.5

1.5

0.75

90L

2.2

-

2.2

1.5

100L

3.7

3.7

2.2

112M

5.5

5.5

3.7

132S

7.5

-

7.5

5.5

132M

11

11

7.5

160M

15

18.5

15

11

160L

Unit: kW

Pole number
Frame number
2P
4P
6P

22

18.5

15

180M

22

30

30

18.5

180L

22

37

37

30

200L

45

45

37

55

55

45

225S

75

75

55

250S

90

90

75

250M

110

110

90

280S

132

132

110

280M

150

150

132

315S



Bearing, Shaft seal

Bracket
number
Gland packing
Bearing
Bearing seal
(in case of an oil seal)
Lubricating oil
Inner diameter x Outer diameter x Width
Q'ty
Pump side
Coupling side
Pump side
Coupling side
Oil amount L
Type

120

28 x 44 x 8

4

6306

6206

TC28408

TC28408

0.28

Turbine
oil

ISO
VG46

130

32 x 51 x 9.5

4

6307

6207

TC32458

TC32458

0.35

140

38 x 60 x 11

4

6308

6307

TC38558

TC35508

0.45

145

42 x 67 x 12.5

4

6309

6308

TC42609

TC40559

0.65

155

48 x 73 x 12.5

4

6310

6309

TC48659

TC45609

0.90

165

55 x 80 x 12.5

5

6312

6311

TC55729

TC50689

1.70

170

75 x 105 x 16

5

NU316

6316

TC7510013

TC7510013

1.80



Features
Structure
Technical data
Selection & Dimensions
Inquiry form


© Yokota Manufacturing Co., Ltd. Tel: +81 82-241-8672 E-mail: yokota@aquadevice.com Terms of Use