Performance / Basic Design
·
Purchaser shall refer the Process data
sheet prepared by the licenser for the Performance parameters of the pump.
· Pumps shall be capable of at least a 5 % head
increase at rated conditions by replacement of the impeller (s) with one (s) of
larger diameter or different hydraulic design, variable-speed capability or use
of a blank stage.
The Max & Min diameter of the impeller
shall be calculated such that the above criteria must be fulfilled. (5.1.6)
· Pumps shall be capable of operating at least up
to the maximum continuous speed. The maximum continuous speed shall be: (5.1.7)
a) Equal to the speed corresponding to the
synchronous speed at maximum supply frequency for electrical motors.
b) At least 105 % of rated speed for
variable-speed pumps, and any fixed-speed pump sparing or spared by a pump
whose driver is capable of exceeding rated speed.
· The purchaser should consider an appropriate
NPSH margin in addition to the NPSHR specified. (5.1.10)
(It
is a general practice to consider the NPSH margin as min. 1meter and if the
pump model selected fail to fulfill this condition then NPSHr test shall be
specified by the purchaser also if the Model selected fail to meet NPSH margin
of 0.6 m then the pump model shall be
rejected.)
· The pump suction-specific speed shall be
calculated in accordance with Annexure A. and shall be limited if specified by
the Licenser. (5.1.11)
· Pumps that handle liquids more viscous than
water shall have their water performance corrected in accordance with HI 1.3
(see Clause 2). Correction factors shall be submitted with proposal and test
curves. (5.1.12)
· Pumps
with stable Head/Flow rate Curves (Continuous head rise to Shut off) are
preferred for all applications if parallel operation is specified.
If Parallel operation is specified, the
head rise from rated point to shut off shall be at least 10%. (5.1.13)
· Pumps shall have a preferred operating region
of 70% to 120% of best efficiency flow rate of the pump as furnished. Rated
flow shall be within the region of 80% to 110% of best efficiency flow rate of
the pump as furnished. (5.1.14)
MAWP
& Pressure casings
· The MAWP shall be at least the max. Discharge
pressure (see 5.3.1 and 5.3.2) plus 10 % of the max. Differential pressure.
(5.3.5 & 5.3.6)
Note: The 10%
differential pressure margin is intended to accommodate head increases (5.1.6),
higher speed in Variable-Speed pumps (5.1.7), and head (testing) tolerance (see
7.3.3.4).
· Unless otherwise specified, pumps with
redially split casings are required for any of the following conditions:
- Pumping Temperature of 200OC (400 OF)
or higher (a lower temperature limit should be considered if thermal shock is
probable).
- A flammable or hazardous pumped liquid with a
relative density of less than 0.7 at specified pumping temperature.
- A flammable or hazardous liquid at rated
discharge pressure above 100 bar (10000 kPa / 1450 psi).
· Centerline supported pump casings shall be
used for all horizontal pumps except as allowed in 8.2.1.2
Hydrostatic
Test Pressure
· All pressure casing components shall be
hydrostatically tested with liquid at a Minimum of 1.5 times the maximum
allowable working pressure with the special provisions as given in clause
7.3.2.1
Corrosion
Allowance (Minimum)
· The Pressure casing shall be designed with a
minimum corrosion allowance of 3 mm or the manufacturer is encouraged to
propose alternative corrosion allowances for consideration if the material of
construction with superior corrosion resistance are employed and if they result
in lower cost without effecting safety and reliability. (5.3.7)
Nozzles
and Pressure casing connections (5.4)
· Openings for nozzles and other pressure casing
connections shall be standard Pipe sizes. Openings of DN 32, 65, 90, 125, 175
and 225 (NPS 11/4, 2 1/2, 3 1/2, 5, 7 and 9) shall not be used. (5.4.1.1)
· Suction and discharge nozzles shall be flanged,
except those on pumps with forged casings, which shall be flanged or machined
and studded. One- and two-stage pumps shall have suction and discharge flanges
of equal rating. (5.4.2.1)
· For pump casings constructed of materials
other than steel or alloy steel or for pumps with nozzles larger than DN 400
(NPS 16), the vendor shall submit allowable nozzle loads corresponding to the
format in Table 4. (5.5.3)
· Allowable forces and moments for Vertical –
Inline pumps shall be twice the values in Table 4 for side Nozzles.
(5.5.2)
Pressure
Casing auxiliary Connection (5.4.3)
· For non-flammable non-hazardous liquids,
auxiliary connections to the pressure Casing may be threaded.
· Unless otherwise specified, pipe threads
shall be tapered threads conforming to ISO 7-1. Openings and bosses for pipe
threads shall conform to ASME B16.5.
External
Nozzle forces and Moments (5.5)
· Steel and alloy steel pumps and their
baseplates and vertically suspended pumps shall be designed for satisfactory
performance if subjected to forces and moments in Table 4. For horizontal pumps
two effects of nozzle loads are considered.
· Allowable forces and moments for vertical
in-line pumps shall be twice the values in Table 4 for side nozzles.
Rotors (5.6)
· Unless otherwise approved by the purchaser,
impellers shall be of fully enclosed type.
· Impellers shall be single-piece castings,
forgings and fabrications.
Wear
rings and running clearances (5.7)
· Mating wear surfaces of hardenable materials
shall have a difference in Brinell hardness number of atleast 50 unless both
the stationery and rotating wear surfaces have the Brinell hardness number of
atleast 400.
· Refer Table-5 for minimum running clearances.
Mechanical
Seal (5.8)
· Pumps shall be equipped with mechanical seals
and sealing systems in accordance with API 682, including pump and seal
interface dimensions (see Table 6 and Figure 25). The purchaser shall specify
the category of seal required. The purchaser should use the data sheets in API
682 for this purpose. (5.8.1)
· Seal glands and seal chambers shall have
provision for only those connections required by the seal flush plan. If
additional tapped connection points are specified and are not used, they shall
be plugged in accordance with 5.4.3.7. (5.8.7)
· If specified, jackets shall be provided on seal
chambers for heating. Heating requirements shall be agreed upon by the
purchaser, vendor, and seal manufacturer for high melting point products. (5.8.9)
· Seal chamber dimensions shall be as per Table
6 - (Standard dimensions for seal chambers, seal gland attachments and
cartridge mechanical seal sleeves)
· Seal chamber face runout (TIR) shall not
exceed 0.5 µm/mm (0.0005 in/in) of seal chamber bore (see annex K).
Material
of construction (5.12)
1. The
purchaser shall specify the material class for pump parts as given at Annex. G.
Table G.1 which provides a guide showing material classes that may be
appropriate for various services. Alternative materials recommended for the
service by the vendor, including material that can improve life and performance
in service, may also be included in the proposal and listed on the final data
sheets.
2. Annex
H, Table H1 provides detail Material of construction of different pump parts.
Purchaser and Manufacturer shall refer MOC of different pump parts against the
material class as specified in the data sheet.
Rotor
Balancing (5.9.4)
· Rotor balancing shall be performed as required
in the specific pump clauses.
· If specified, impellers, balancing drums and
similar rotating components shall be dynamically balanced to ISO 1940-2.5 grade
G1
Couplings
& Coupling Guard (6.2)
· Couplings and guards between drivers and driven
equipment shall be supplied and mounted by the manufacturer of the pump. (6.2.1)
· If specified Coupling shall be balanced to
ISO 1940-1 grade G-6.3 (6.2.3)
· If specified coupling shall meet the
requirement of API 671. Couplings operating at speeds in excess of 3800 r/min
shall meet the requirements of ISO 10441 or API 671 for component balancing and
assembly balance check. (6.2.4)
· The spacer nominal length shall be at least
125 mm (5 in) and shall permit removal of the coupling, bearings, seal and
rotor, as applicable, without disturbing the driver or the suction and
discharge piping.(6.2.2 –d)
Base
Plate (6.3)
· Single-piece drain-rim or drain-pan base plates
shall be furnished for horizontal pumps. The rim or pan of the base plate shall
be sloped at least 1 in 120 toward the pump end, where a tapped drain opening
of at least DN 50 (2 NPS) shall be located to effect complete drainage. (6.3.1)
· If specified, the baseplate and pedestal
support assembly shall be sufficiently rigid to be mounted without grouting. (6.3.13)
Heating
and cooling requirement (6.5.3)
· The arrangement for cooling water system shall
conform to. Annex. B, Fig. B.1, B.2, B.3, B.4, B.5, B.6, B.7, B.8, B.9 (as
applicable)
· Unless otherwise specified, valves shall be
furnished on all manifolded inlet and outlet connections. (6.5.3.4)
Bearing
(5.10)
· Each shaft shall be supported by two radial
bearings and one double-acting axial (thrust) bearing which may or may not be
combined with one of the radial bearings.
Bearings shall be one of the following
arrangements:
Ø rolling-element radial
and thrust.
Ø hydrodynamic radial and
rolling-element thrust.
Ø Hydrodynamic radial and
thrust.
· Unless otherwise specified, the bearing type
and arrangement shall be selected in accordance with the limitations in Table 9
or as specified by the purchaser. (5.10.1.1)
Lubrication (5.11)
· Unless otherwise specified, bearings and
bearing housings shall be designed or oil lubrication using a mineral
(hydrocarbon) oil. (5.11.1)
The Applicability for Forced Lubrication
system depends upon the type of Application.
The requirement for Heat
tracing shall depends upon the site conditions. It is a usual practice to
provide Heat tracing for the Lubrication system if the min. Atmospheric
temperature at the site shall be below 5 deg. C
Inspection
& testing requirement (7.3)
Inspection and testing
requirement shall be as per the Purchaser approved Inspection and testing plan
prepared by the Vendor
General
· Performance and NPSH tests shall be conducted
using the methods of ISO 9906 grade 1, HI 1.6(for centrifugal pumps) or HI 2.6
(for vertical pumps), except that efficiency shall be for information only and
not rating. Performance tolerances shall be in accordance with Table 14.
(7.3.1.1)
Hydrostatic
test (7.3.2)
· All pressure-casing components shall be
hydrostatically tested with liquid at a minimum of 1.5 times the maximum
allowable working pressure, with the special provisions specified in cause
7.3.2.1.
Performance
test (7.3.3)
· Unless otherwise specified, each pump shall be
given a performance test. Performance tests shall be performed using water at a
temperature less than 65 °C (150 °F). (7.3.3.1)
· Performance Tolerances shall be as per Table
14.
· During the performance test, the requirements
of a) through d) below shall be met. (7.3.3.4)
a)
Vibration
values shall be recorded during the test in accordance with 5.9.3.2. Vibration
values shall not exceed those given in 5.9.3.6.
b) Pumps shall operate within bearing temperature
limits as defined in 5.10.2.4 and shall not display signs of unfavorable
operation, such as noise caused by cavitations.
c) When operated at rated speed, pumps shall
perform within the tolerances given in Table 14.
d) If specified, true peak bearing-housing
velocities shall also be recorded for information only.
NPSHR
test (7.3.4.2)
· The requirement for the NPSHR test depends upon
the NPSH margin of the Pump model selected by the vendor. A general practice
for the requirement of NPSH test is as stated above.
Complete Unit test (7.3.4.3)
· If specified, the pump and driver train,
complete with all auxiliaries that make up the unit, shall be tested together.
If specified, torsional vibration measurements shall be made to verify the
vendor’s analysis. The complete-unit test shall be performed in place of or in
addition to separate tests of individual components specified by the purchaser.
Sound
Level test (7.3.4.4)
· If specified, sound level tests shall be
performed as agreed between the purchaser and the vendor. The minimum
sound level for the Pump and Driver train shall be determined by the Purchaser
or client requirement. As a General practice Noise measured from the Running
Equipment at a distance of 1 m shall be equal to or less then 85dbA
Auxiliary
Equipment test (7.3.4.5)
· If specified, auxiliary equipment such as oil
systems, gears and control systems shall be tested in the vendor’s shop.
Bearing
Housing resonance test (7.3.4.6)
· If a resonance test is specified, the bearing
housing(s) shall be excited by impact or other suitable means with the pump un piped,
and the natural frequency (ies) shall be determined from the response.
Mechanical
run test (7.3.4.7)
· If specified, the pump shall be mechanically
run for 4 hr. unless otherwise specified or agreed, this run shall be performed
at rated flow. (7.3.4.7.2)
Materials
Inspection (7.2.2)
· NDE shall be performed as required by the
material specification. If additional radiographic, ultrasonic,
magnetic-particle or liquid-penetrant examination of the welds or materials is
specified by the purchaser, the methods and acceptance criteria shall be in
accordance with the standards shown in Table 13.
Alternative standards may be proposed by
the vendor or specified by the purchaser. The welding and material inspection
data sheet in Annex N may be used for this purpose. (7.2.2.1)
· If specified, the purchaser may inspect for
cleanliness of the equipment and all piping and appurtenances furnished by or
through the vendor before assembly. (7.2.2.2)
· If specified, the hardness of parts, welds and
heat-affected zones shall be verified as being within the allowable values by
testing. The method, extent, documentation and witnessing of the testing shall
be agreed upon by the purchaser and the vendor. (7.2.2.3)
Driver
Selection (6.1)
Motor
Driver
· The purchaser shall specify the type and specification
of driver required. (6.1.1)
· Motors shall have power ratings, including the
service factor (if any), at least equal to the percentages of power at pump
rated conditions given in Table 11. (6.1.3)
· The purchaser shall specify the type of motor,
its characteristics and the accessories, including the following: (6.1.4)
a) Electrical characteristics;
b) Starting conditions (including the expected
voltage drop on starting);
c) Type of enclosure;
d) Sound pressure level;
e) Area classification;
f) Type of insulation;
g) Required service factor;
h) Ambient temperature and elevation above sea
level;
i) Transmission losses;
j) Temperature detectors, vibration sensors and
heaters, if these are required;
k) Vibration acceptance criteria;
l) Applicability of IEC 60034, API 541 or IEEE
841.
Steam
Turbine Driver
o Unless otherwise specified, steam turbine
drivers shall conform to ISO 10436 or API 611. Steam turbine drivers shall be
sized to deliver continuously 110 % of the pump rated power at normal steam
conditions. (6.1.8)
o Unless otherwise specified, gears shall conform
to API 677. (6.1.9)
Preparation
for Shipment (7.4)
· Type of packing required shall be based on the
location of vendor manufacturing unit whether Domestic or International
· Period for the Pump outdoor storage shall be
as per the client requirement.
Shipment for spare rotor (8.2.8)
· Spare rotors and Cartridge- type elements
shall be prepared for vertical storage when specified by the purchaser. (8.2.8.2)
· If specified by the Purchaser a shipping and
storage container designed to store the rotor or cartridge vertically shall be
provided. (8.2.8.3)
· If specified by the Purchaser the shipping and
storage container shall be designed to allow inert gas inhibition
during storage. (8.2.8.4)
Instrumentation (6.4)
· As per the project requirement shall be
specified which shall be installed and tested in accordance with API 670.
· For equipment with Hydrodynamic Bearings,
provision shall be made for mounting two radial vibration probes in each
bearing housing, two axial position probes at the thrust end of each machine,
and a one event per revolution probe in each machine. (6.4.2.2)
