2 name nomenclature, 3 design of major parts, 4 performance and operating limits – Flowserve MARK 3 GROUP 4 User Manual

Page 13

Advertising
background image

MARK 3 GROUP 4 USER INSTRUCTIONS ENGLISH 71569286 08-12

Page 13 of

48

flowserve.com

®

with a rust preventative compound and openings are

provided with covers or plugs. Shaft packing, when

required, is shipped with the pump and should not be

installed until the pump is ready to run. Mechanical

seals, when provided, are factory installed and

adjusted prior to shipment. The axial impeller

running clearance is preset at the factory but should

be checked prior to final alignment in case of

tampering.

3.2 Name nomenclature

The pump size will be engraved on the nameplate.

The following example explains how the pump name

identifies the construction features and options.


4K10x6-18OP

Group size

Power end

Nominal suction branch size

Nominal discharge branch size

Nominal maximum impeller diameter

Open impeller

3.3 Design of major parts

3.3.1

Pump casing

The pump casing is a volute type casing with

integrally cast feet and top centerline discharge

nozzle. It is a one piece pressure retaining casting

with gasket connections to the stuffing box head and

the suction and discharge flanges.

3.3.2

Impeller

The impeller is semi-open design, keyed to the shaft

and secured with a contoured impeller nut. The

vanes of the impeller are Francis type.

3.3.3

Shaft

The large diameter stiff shaft, mounted on bearings,

has a keyed drive end.

3.3.4

Pump bearings and lubrication

Ball bearings are fitted as standard and may be

either oil or grease lubricated. Oil lubrication is only

available where the pump shaft is horizontal.

3.3.5

Bearing housing

For oil lubricated bearings, a bulls eye level gauge is

supplied. Constant level oilers can also be fitted. Two

grease nipples enable grease lubricated bearings to

be replenished between major service intervals.

3.3.6

Stuffing box housing

The stuffing box housing has a spigot (rabbet) fit

between the pump casing and bearing housing for

optimum concentricity. The design enables a

number of sealing options to be fitted.

3.3.7

Shaft seal

The mechanical seal(s), attached to the pump shaft,

seals the pumped liquid from the environment.

Gland packing may be fitted as an option.

3.3.8

Driver

The driver is normally an electric motor. Different

drive configurations may be fitted such as internal

combustion engines, turbines, hydraulic motors etc

driving via couplings, belts, gearboxes, drive shafts

etc.

3.3.9

Accessories

Accessories may be fitted when specified by the

customer.

3.4 Performance and operating limits

This product has been selected to meet the

specifications of your purchase order see section 1.5.

The following data is included as additional

information to help with your installation. It is typical,

and factors such as temperature, materials, and seal

type may influence this data. If required, a definitive

statement for your particular application can be

obtained from Flowserve.

3.4.1

Operating limits

Pumped liquid temperature limits

up to+177 ºC (350 ºF)

Minimum ambient temperature

-20 ºC (-4 ºF)

Maximum ambient temperature

+50 ºC (122 ºF)

Maximum soft solids in suspension

up to 7 % by volume

Maximum pump speed

Refer to the nameplate

3.4.2

Speed torque curves

To bring a centrifugal pump up to rated speed, the

driver must be capable of providing more torque at

each speed than required by the pump. The margin

between the available and required torque affects the

time it takes the unit to reach full speed. If the torque

required by the pump exceeds the torque capability

of the drive at any run-up speed, the unit will not

accelerate to full speed. Normally, this is not a

problem with standard induction or synchronous

motors provided the proper voltage is supplied at the

motor.

For pumps started at shut valve conditions, 100

percent full speed torque can be calculated by using

the formula:

Torque (Nm) = 9545 Shutoff Power (kW)

r/min

Advertising