Service Factor for the Water Turbine & Screw Compressor :
Kw/1000 rpm = ( 75 Kw x 1000 x 2 ) /1500
Kw/1000 rpm = 100
Coupling Selection based on max rating : A4B
Coupling Bore Capacity : 75 mm
Maximum Speed for the A4B is 3275 rpm unbalanced
DBSE for the A4B Type SP is 140 mm
The A4B Type is acceptable in this application
Coupling insert removable without the need to remove either driving or driven equipment.
Change out of coupling insert is faster than other coupling
No lubrication or maintenance required over the life of the insert
The polyutherane insert can be supplied in a variety of hardness to optimise torque
capacity and damping.
Polyutherane is very resistant chemical attack.
Standard insert can be handle large temperature range iron from -40 o c to 80 o c
Hubs can be rotated independently during motor test
No metal – to – metal contact
Large bore to torque capacity
Vertical operation possible with standard coupling.
Retaining rings provided with locking screws as standard.
Once hubs (A) and (B) holding ring (D) have been installed and aligned on the shafts
the coupling hubs will not have to be moved again during the life of the equipment.
The elastic insert (C) can then be installed between the parallel slots formed by
the hub teeth.
With the insert position, slide the retaining ring (D) into position over the the
polyurethane insert. Centrifugal force will expand the insert under operation ensuring
a tight, secure fit inside the retaining ring.
Removing and replacing the coupling insert is very simple and requires no special
tools. By removing the retaining ring, the insert can be quickly and easily removed
and replaced without the need to undo the screws, bolts or fasteners.
The Samiflex elastic insert is manufactured from a special blend of polyurethane
compound manufactured to best meet the demanding characteristics of a high performance
elastic coupling.
Samiflex elastic inserts are offered in three styles of compound and five hardness
ratings allowing the most appropriate insert to be selected for the application.
The standard elastic insert is supplied at 95 shore and is a yellow color. High performance
inserts type HD and HDT are colored ochre and red respectively and enable Samiflex
torque ratings to be increased by 40% (consult factory).
THE ELASTIC INSERT
Only four parts to the Samiflex Coupling
The two identical hubs ( items A & B) are manufactured in cast iron, cast steel
or aluminium and incorporate four, six or eight teeth, depending on size rating of
the coupling.
A precision cast and machined polyurethane insert ( item C ) fits between the hubs
and is split axially so fitting and removal can be achieved without removing hubs.
The holding ring, manufactured in steel, polyamide or bronze ( item D) is fitted
over the insert securing both insert and ring between hubs. The coupling requires
no bolts and nuts.
Samiflex COUPLINGS
The range of Samiflex Couplings has been approved under ATEX directive 94/9EC – for
use in potentially explosive atmospheres.
Now there’s a new solution to one of the most costly and troublesome problems facing
maintenance personnel - coupling failure and the expensive down time associated with
fixing it
Couplings and Fluid Drives
Insert
Ref
Hardness
Colors
Temp Rating
80 Shore A
Clear
-40°C /80°C
90 Shore A
Blue
Standard
STD
95 Shore A
Yellow
High Temp
HT
95 Shore A
Orange
-40°C /140 °C
High Performance
HD
97 Shore A
Ochre
-40°C /80°C
HDT
97 Shore A
Red
-40°C /140 °C
HR
65 Shore D
Green
-40°C /140 °C
Coupling Selection
Method
Application details (for service factor)
Kilowatt and rpm of the driver
Shaft details of the driving and driven equipment
Determine the service factor (SF) from the application and classification lists noted
below
Calculate the maximum Kw/1000 rpm rating:Kw/1000 rpm = (Kw x 1000 x SF ) /rpmSelect
the coupling which has a higher max rating
Compare the maximum rpm capacity & bore requirements to the catalogue limits for
the coupling selected
Load Characteristics
Electric Motor
Steam Turbine
Glass turbine
Steam Engine
Water Turbine
8 Cel. Recip Engine
6 Cyl. Recip. Engine
4 Cyl. Recip. Engine
Constant Torque
1.0
1.5
2.0
2.5
eg.Centrifugal pumps,compressors & blowers,
light duty agitators and fans
Slight Fluctuations
1.5
2.0
2.5
3.0
eg. Slurry pumps, Screw compressors,
Lobe and Vane Blowers.
Moderate Fluctuations and or
2.0
2.5
3.0
3.5
Slight Shock Loads
Doubling acting pumps, Rec Comp
Large Fluctuations and/or
2.5
3.0
3.5
4.0
Moderate Shock Loads
1 or 2 Cylinder Recip pumps
Shock loads or
3.0
3.5
4.0
Consult factory
Light Torque Reversals
Slitters, Rod Mill,Hot Mill
Heavy Shock Loads or
Consult Factory
Consult Factory
Consult Factory
Consult Factory
Large Torque Reversals
Feed rolls , Reversing Mills
(1) Use a minimum Service Factor of 1.25 when driving through a gearbox or using
a direct on-line electric motor
(2) Consult Autogard when using a reciprocating engine with fewer than 4-cylinders.
(3) Service Factors are for reference only. Customer experience may dictate the selection
of different service factors.