|
|
 |
 |
 |
Purchase Cost - Increased |
|
Power Consumption - Affected |
|
Operation at Excess Capacity, Requires Greater NPSH
(A) |
|
High Pressure Drop through Foot Valve and Suction
Lift |
|
Cavitation - Efficiency Drop and premature Failure
of Rotor |
|
|
 |
| Pump
Selection |
|
Do not oversize pumps. This leads to uneconomical
operation and generally narrows the safe operating
range of capacities. |
|
Do no try to select pumps with excessively low NPSH
(Net Positive Suction Head). |
|
Do not falsify real available NPSH, trying to keep
a margin up your sleeve. This leads to selection
of pumps with excessively high Suction Specific
Speeds and high minimum flows. |
|
Do evaluate economical advantages of variable speed
operation. It is more efficient and results in longer
pump life. |
|
Do not overestimate value of pump efficiency if
it is obtained at the cost of reliability. |
|
Do not use mechanical seal when packing is more
than adequate for the intended service. |
| Installation |
|
Do provide sufficient submergence over intake piping
to prevent vortex formation. |
|
Do not use suction elbows in a plane parallel to
the shaft; place them in a plane perpendicular to
the shaft. |
|
Do not use the pump casing as an anchor for the
piping. If you use expansion joints, support and
anchor them independently of the pump. |
|
Do provide adequate flow, pressure, and temperature
instrumentation for each pump. |
|
Pump and driver alignment must be rechecked under
normal operating conditions. |
| Operation |
|
Do not operate pumps below the recommended minimum
flow. |
|
Do not operate pumps with suction valve closed. |
|
Do not run two pumps in parallel when a single pump
can carry the reduced system load. |
|
Do not stop a pump while it is cavitating. Re-establish
normal operations first and then, stop the pump
if you have to. |
|
A pump handles liquids. Keep air out. |
|
Do not run a pump if excessive noise or vibration
occurs. |
|
Do run spare pumps occasionally to check their availability |
| Maintenance |
|
Run a performance test at reasonable intervals of
time, to follow effect of increased internal clearances. |
|
Do not open pumps for inspection unless factual
or circumstantial evidence warrants it. |
|
Do not over-lubricate grease lubricated bearings. |
|
Do not overcool outer races of ball bearings. Inner
races continue to expand and balls are squeezed
out of shape. |
|
Packing stuffing boxes is an art. Do not assign
this task to inexperienced personnel. |
|
Do not tighten stuffing box glands excessively.
Let enough leakage flow to cool and lubricate packing. |
|
Do monitor the pressure drop across suction strainers.
An excessive pressure drop indicates clogging and
may reduce available NPSH to a dangerous degree. |
|
Do keep an adequate stock of spare parts. |
|
Except in an emergency, use original equipment manufacturer's
replacement spares. |
|
Consider upgrading material for parts that wear
or corrode too rapidly. This lengthens inteval between
overhauls. |
|
Do examine and recondition, if necessary, all metal-to-metal
fits. |
|
Do examine parts for corrosion, erosion, or other
damage. |
|
Do check concentricity of all parts of the rotor
before reassembly. |
|
Do use new gaskets for complete overhaul. |
|
|
|
 |
-
Pump is the only mechanical means available to transport
fluids
-
50-55% of the connected load is "Pump Load"
- It
is pertinent any system which consumes maximum energy
should merit attention for "Energy Conservation"
|
| ENERGY
WASTAGE FACTORS |
|
Electric Motor Capacity: if motor capacity
is far more than the actual, losses in electric
transmission increases resulting in overall wastage
of energy.
| |
Power
= V x I x Cos q
V = Voltage, I = Current, Cos q = Power factor. |
|
|
Efficiency Vs. Price Trade-off: Efficiency
is inversely proportional to power requirement.
An efficient pump will consume less power and will
be costly. |
|
Pumps not working at duty:
Often,
system designers want to be extra cautious.
More safety margins make the pump operate away from
the specified duty point. |
|
Unrealistic Head :
Power is proportional to head
By some means, we have to control head.
Change pipe dia, length, material, and reduce number
of bends, valves etc.
Huge amounts of energy can be saved if wasteful
use is avoided. |
|
|
|
|
|
| |
|
SAM equipped with test facilities for
Raw material, inprocess, Hyrdotest, performance test
suitable for Horizontal and Vertical for high flow rate
/ high energy testing. We have the ability to perform
the following testing standards.
|
| TESTING
STANDARDS |
| TYPE
OF TEST |
TESING
STANDARD |
| |
|
| RAW
MATERIAL |
| HARDNESS
TEST |
IS
3804 |
| MAGNETIC
PARTICLE |
ASTM
E709/E139 |
| ULTRASONIC
TEST |
ASTM
SA388 |
| RADIOGRAPHY
TEST |
ASTM
E446 LEVEL IV FOR CI FAMILY |
|
ASTEM
E446 LEVEL III FOR STEEL CAST
CASTINGS |
| IN-PROCESS |
| DYE
PENTRANT TEST |
ASTM
E165 |
| STATIC
& DYNAMIC BALANCING ISO 1940-1973 (E) G.6.3
(ONLY FOR THE IMPELLER) |
| FINAL
INSPECTION |
| HYDROSTATIC
TEST |
| HIS |
(a)
Shall be tested for 1.5 times of pressure occur
at rated condition.
(b) 1.25 times of pressure occur at discharge valve
closed
condition greates of (a) and (b) :
Testing duration : Min. 5 Minutes. |
IS-5120
177
Amt.No.3 Sep'1984 |
Shall be tested for 1.5 times
of max.discharge pressure experienced by the pump
casing or diffuser bowl.
|
| API
610 7TH Edition |
Shall
be tested for 1.5 times of max. allowable working
pressure.
Testing duration : 30 Minutes Minimum. |
| PERFORMANCE
TEST |
| IS-5120 |
Shall
be tested at rated speed upto 75 KW and at reduced
speed for more than 75 KW.
Duration of Test : Shall not be less than
1 Hour. |
| Quantum
of Testing |
10% of a batch subject to a minimum
of 10 pumps shall be tested. If the production
batch is less than 10 pumps, entire batch is to
be tested.
|
| HIS
|
Pumps are allowed test to reduced
speed and readings to be converted to rated speed
as per affinity law.
|
| API
610 |
As
per Clause No.4.3.1.1., Performance and NPSH Tests
shall be carried out as per Hydraulic Institute
Standard.
|
| NPSH
TEST |
| HIS
|
NPSH
at duty point by suction throttling method /
Vaccum chamber method. |
| API
610 |
NPSH
Test shall be carried out at following points
:
1. Minimum flow 2. Rated flow.
3. Between Minimum & rated flows. 4. 110%
of rated flow
|
| (
We can test NPSH at duty point a by suction throttling
method ) |
| VIBRATION
|
| HIS |
As
per chart No.66 & 67 of HIS with respect to
operating speed. |
| API
610 |
Sound
level shall be in accordance with API 615.
Acceptable limit : 50 Microns amplitude and
at the velocity of 4.5 M/Sec. |
| NOISE
LEVEL |
| HIS |
Acceptable
limit : 85 db measured at a distance of 1.5
M from the major surface of the machine. |
HIS
= Hydraulic Institute Standard, API
= American Petroleum Industry, IS
= Indian Standard.
|
|
Click here
to view the list of Metallurgical Data |
 |
|
|
|
|
|
|
|
