ISO 3555:1977

INTERNATIONAL STANDARD
3555
INTERNATIONAL ORGANIZATION FOR STANDARDIZATION l MEXKAYHAPOAHAJl OPTAHM3ALWI l-IO ~AHAAPTZ13A4IMW*ORGANISATION INTERNATIONALE DE NORMALISATION
Centrifugal, mixed flow and axial Pumps - Code for
acceptance tests - Class B
Pompes centrifuges, hblico-centrifuges et h&VicoYdes - Code d’essais de rkeption - Classe B
First edition - 1977-03-01
UDC 621.65 : 620.16
Ref. No. ISO 3555-1977 (E)
Descriptors : centrifugal Pumps, axial flow Pumps, acceptance inspection, Performance tests,
testing conditions, test equipment.
Price based on 36 pages

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FOREWORD
ISO (the International Organization for Standardization) is a worldwide federation
of national Standards institutes (ISO member bodies). The work of developing
International Standards is carried out through ISO technical committees. Every
member body interested in a subject for which a technical committee has been set
up has the right to be represented on that committee. International organizations,
governmental and non-governmental, in liaison with ISO, also take part in the work.
Draft International Standards adopted by the technical committees are circulated
to the member bodies for approval before their acceptance as International
Standards by the ISO Council.
International Standard ISO 3555 was developed by Technical Committee
ISO/TC 115, Pumps, and was circulated to the member bodies in Februar-y 1975.
lt has been approved by the member bodies of the following countries :
Austria Israel Spain
Belgium Italy Sweden
Bulgaria Japan Switzerland
Canada Mexico Turkey
France United Kingdom
Netherlands
Germany Poland Yugoslavia
Hungary Romania
disapproval of the
The member bodies of the following countries expressed
document on technical grounds :
Austral ia
U .S.A.
0 International Organkation for Standardkation, 1977 l
Printed in Switzerland
ii

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Page
CONTENTS
.........................................
0 Introduction 1
..............................
1 Scope and field of application 1
2 Symbols. . 2
........................
2.1 List sf Symbols used in the test code 2
.................
2.2 Alphabetical lists of basic letters and subscripts 3
..........................................
3 Definitions. 4
....................................
3.1 General definitions 4
........................
3.2 Definitions peculiar to the test Code. 4
..........................................
4 Guarantees. 6
..................................
4.1 Subjects of guarantees 6
............................ 6
4.2 Other conditions of guarantee.
................................ 6
4.3 Fulfilment of guarantee.
6
5 Tests.” .
.................................. 6
5.1 Organization of tests.
.................................... 7
5.2 Test arrangements.
...................................... 9
5.3 Test conditions
...............................
5.4 Accuracy sf measurement 11
6 Procedure for measurement of rate of flow, head, Speed of rotation and
......................................... 11
power input.
...............................
6.1 Measurement of flow rate. 11
..................................
6.2 Measurement of head 12
.......................
6.3 Measurement sf the Speed of rotation. 18
.........................
6.4 Measurement of pump power input 18
................
6.5 Measurement sf pumping unit Overall efficiency. 19
......................................
7 Cawitation testing 19
...........................................
7.1 General. 19
................ 20
7.2 Determination of (NPSH) required by the pump.
.................... 20
7.3 Limits of error in determination of (NPSH)
7.4 Measurement of pump head, outlet flow rate, Speed of rotation, power
...................... 20
input (if necessary) and vapour pressure
. . .
Ill

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8 Tests on Pumps for liquids other than clean cold water. . 24
........................ 24
8.1 Characteristics of “clean cold water”
24
8.2 Characteristics of liquids for which clean cold water tests are acceptable .
....................................... 24
9 Analysis of tests
24
..........................
9.1 Test data required for the analysis
9.2 Translation of the rest results to the guarantee basis . 24
9.3 Measuring inaccuracies. . 25
9.4 Verification of guarantee . 25
9.5 Test report . 26
Annexes
...................... 27
A Effect of pre-swirl induced by the pump.
...............
B Pumping installation under non-Standard conditions 28
........................................ 28
C Friction losses
...............................
D Costs and repetition of tests 32
33
E List of reference documents .
34
F Conversion to SI units. .
.......................................... 35
G Checklists
..................................... 36
H Pumptestsheet.

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ISO 35554977 (E)
INTERNATIONAL STANDARD
Centrifugal, mixed flow and axial Pumps - Code for
acceptance tests - Class B
WARNING - Terms used in this International Standard like “guarantee” or “acceptance” shall be understood in a technical
but not in a legal sense. The term “guarantee”, therefore, specifies values for checking purposes determined in the contract,
but does not say anything about the rights or duties arising, if these values are not reached or fulfilled. The term
“acceptance” does not have any legal meaning here, either. Therefore, an acceptance test carried out successfully alone does
not represent an “acceptance” in the legal sense.
0 INTRODUCTION The conditions in which Pumps are finally installed,
however, often do not permit reliable tests measurements,
This International Standard is the second of a set of three
and recommendations are made concerning the procedure
dealing with acceptance tests of centrifugal, mixed flow and
to be adopted where the layout precludes tests in conformity
axial Pumps l); they correspond to three classes of tests A,
with the Standards, or where the tests cover the pump and
B and C*); class A is the most accurate and class C is the
the plant ancillary to the pump itself.
least accurate; the use of classes A and B is restricted to
special cases when there is need to have the pump perform- In this test Code, all formulae are given in coherent units.
ante more precisely defined.
1 SCOPE AND FIELD OF APPLICATION
Attention is drawn to the fact that class B and A tests
require more accurate apparatus and methods, which
This International Standard constitutes a code for
increase the tost of such tests.
acceptance testing of Pumps, defining the terms and
quantities that are used, establishing the methods of testing
The Standard arrangements and procedures described are
and the ways of measuring the quantities involved according
those to be employed for testing a pump individually,
to class B so as to ascertain the performances of the pump
without reference to its final installation conditions or the
and to compare them with the manufacturer’s guarantee.
effect upon it of any associated fittings, these being the
usual conditions in which a pump is tested at the
Pn general this code applies to any sizes of Pumps tested
manufacturer’s works.
with clean cold water and other liquids behaving as clean
cold water such as defined in clause 8.
Pump Performance may be affected by conditions of the
This code is not concerned with the structural details of the
final site installation, and procedures are described for
on certain types of pump nor with the mechanical properties of their
carrying out “Standard tests”
components.
installations of which an Overall Performance is required.
1) In the rest of the text these types of Pumps will be simply designated as “pumps”.
2) ISO 2548.

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ISO 35554977 (E)
2 SYMBOLS
2.1 List of Symbols used in the test code
TABLE 1 - Symbols
Reference Reference
number in number in Quant@ Symbol Dimension& SI units
ISO 3555
ISO 31’)
3.1 .l Mass m M
kg
1.3.1 / L m
Length
1.6.1 t T S
Time
4.2.1 8 0 “C
Temperature
A L2 m2
1.4.1 Area
L3 m3
1.5.1 Vol ume V
1.8.1 Angular velocity Ld T-1 rad Js
1 .lO.l Velocity V LT-’ mJs
Ill.2 Acceleration of free fall LT-2 mJs2
9
2.3.2 Speed of rotation n T-1 s-1
3.2.1 Density ML-3 kgJm3
P
3.11 .l Gauge pressure ML-‘T-2 Pa-
Pe
3.19.1 Viscosity (dynamic viscosity) ML-‘T--l Pa.s
P
3.20.1 Kinematic viscosity V LZT- ’ m2Js
3.22.2 Energy E M LZT- 2 J
3.23.1 Power (general term) P M LZT-3 w
12.1 Reynolds number Re pure number
Diameter D L m
3.2.1 .l Mass rate of flow MT- ’ kgJs
qrn
3.2.1.2 Volume rate of flow L3T- ’ m3Js
qv
3.2.3.2 Distance to reference plane Z L m
3.2.3.8 Pump total head H L m
3.2.3.6 Inlet total head L m
Hl
m
3.2.3.7 Outlet total head L
u2
Y LZT- 2
3.2.3.9 Specif ic energy JJkg
L m
3.2.3.10 Loss of head at inlet
HJI
L m
3.2.3.11 Loss of head at outlet
HJ2
L m
3.2.3.12 Net positive suction head (NPSHj3)
Pa
ML-‘T-2
Atmospheric pressure (absolute)
Pb
Pa
ML-‘T-2
Vapour pressure (absolute)
PV
ML2T-3 W
3.2.4.2 Pump power input
Pa
ML2T-3 W
3.2.4.1 Pump power output
4.4
M LZT-3 W
3.2.4.3 Motor power input
p,r
pure number
3.2.5.1 Pump eff iciency
rl
pure number
3.2.5.2 Transmission efficiency
r7ir-H
pure number
3.2.5.3 Motor eff iciency
qmot
pure number
3.2.5.4 Overall eff iciency
%r
pure number
3.2.6 Type number K
pure number
6.2.1.2 Friction factor h
1 1) ISO 31 (See annex E.)
!) M = Mass 0 = Temperature
L = length T = Time
$1 An optional Symbol for net positive suction head is H,.

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ISO3555=1977(E)
2.2 Alphabetical lists of basic Letters and subscripts
TABLE 2 - Letters used as Symbols
TABLE 3 - Letters and figures used as subscripts
Symbol SI units
Quantity
A Area m2
value at the specified Speed
D Diameter m
E Energy J
Acceleration of free fall m/s2
!?
H Head m
m
Losses in terms of head of liquid
HJ
K pure number
Type number
k m
Absolute roughness
/ m
Length unit (Overall)
m
Mass intermediate
kg
n
Speed of rotation S-’
(NPSH)
Net positive suction head m 1) general case : mean
2) related to q : mass
P
Pressu re Pa
manometric
W
Power
P
Mass rate of flow kg/s
qm
m3/s
Volume rate of flow
QV
Re Reynolds number pure number
t Time S
V Velocity mls
V
Volume m3
X
Tolerante pure number
Y Specific energy Jkg
Z Distance to reference plane m
Efficiency pure number
rl
8 Temperature “C
h Friction factor pure number
Dynamit viscosity Pas
P
V Kinematic viscosity m2/s
Density
P kg/m3
w Angular velocity rad/s
1) This indication applies to the values of quantities relating to the guarantee Point.
3

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ISO 3555-1977 (E)
3 DEFINITIONS 3.2 DEFINITIONS PECULIAR TO THE TEST CODE
This sub-clause gives the definitions of concepts used in
3.1 GENERAL DEFINITIONS
this test Code, together with the associated Symbols, if any
have been allocated.
In Order to avoid any error of interpretation it has seemed
preferable to reproduce here the definitions of quantities and
Concepts, even though in current use, which are not strictly
units as given in ISO 31 and to Supplement these definitions
necessary to the application of this code are not here
by some specific information on their use in this test Code.
defined.
g - acceleration of free fall?
n- The quotient of the number of
Speed of rotation :
3.2.1 Flow rates
rotations by the time.
3.2.1.1 qm - In this test Code, mass rate of flow designates
p - density : Mass per unit volume.
the external mass rate of flow of the pump, i.e. the rate of
flow discharged into the pipe from the outlet branch of the
p - pressure : The quotient of forte by area. Unless other-
Pump.
wise specified, all pressures are gauge pressures, i.e. measured
with respect to the atmospheric pressure.
NOTE - Losses or abstractions inherent to the pump, i.e. :
a) discharge necessary for hydraulic balancing of axial thrust;
viscosity (dynamic viscosity, sometimes called absolute
P-
viscosity) is defined by the expression : b) cooling of bearings of the pump itself;
c) water seal to the packing;
7
d) leakage from the fittings, internal leakage, etc.;
are not to be reckoned in the quantity delivered. On the contrary, if
where
they are taken at a Point before the flow measuring section, all
derived quantities used for other purposes, such as :
is the velocity of a f lat plate moving in its own plane
uO
e) cooling of the motor bearings;
while keeping parallel to
a fixed flat Wall;
f) cooling of a gear-box (bearings, oil cooler), etc., should be
h is the distance from the flat plate to the fixed flat added to the measured rate of flow.
Wall;
3.2.1.2 q, - The outlet volume rate of flow has the
7 is the friction forte of the fluid on the unit area of
following value :
the flat plate during its motion.
qrn
NOTE - h should be small enough to obtain laminar flow of the
=-
q”
fluid between the flat plate and the fixed flat Wall.
p2
11 - kinematic viscosity : The quotient of the viscosity
In this test Code, this Symbol may also designate the volume
(dynamic viscosity) by the density :
rate of flow in a given section2); it is the quotient of the
mass rate of flow in this section by the density. (The section
P
=- may be designated by the proposed subscripts.)
V
P
P - power : The quotient of the energy transferred during
3.2.2 v - Velocity of flow : The mean velocity of flow
a time interval by the duration of this interval.
equal to the volume rate of flow divided by the pipe
Re - Reynolds number is defined by the expression : Cross-section 2, :
VD
%
ße=-
V=Ä
V
1) For class B tests, the local value of g should be used. Nevertheless, in most cases, a value of 9,81 m/s2 would not involve significant error.
The local value should be calculated by the formula :
g = 9,806 17 (1 - 2,64 X 1 O-3 cos 2~ -t 7 X 1 O+ cos2 2~1- 3,086 X 1 O+ Z
where ‘p and 2 are respectively the latitude and the altitude.
2) Attention is drawn to the fact that in this case q, may vary for different reasons across the circuit.
4

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ISO35554977 (E)
3.2.3 head : The energy per unit weight of fluid. 3.2.3.7 H, - outlet total head : The total head in the
outlet section of the pump :
3.2.3.1 reference plane : The horizontal plane through the
2
centre of the circle described by the external Point of the p2 v2
=z2 +-+--
u2
entrance edges of the impeller blades; in the case of double
P2S 29
inlet Pumps the plane should be taken through the higher
centre.
3.2.3.8 H - pump total head : The algebraic differente
The manufactu rer should indicate the Position of this between the outlet total head, and the inlet total head.
with respect to precise reference Points on the pump.
H=H,-Hl
If the vari ation of density of the liquid is not
3.2.3.2 z designates the differente between the level of the
signif icant,
horizontal plane under consideration and the level of the
2 2
reference plane. Its value is
p2-Pl v2 -vl
+
H=z,-z, +-
PSI 29
- positive, if the plane in question is above the reference
plane;
the pumped liquid is signif
lf the variat ion of density of
replaced by the mean value
p should be
- negative, if the plane in question is below the
reference plane.
Pl +p2
=-
Pm
2
3.2.3.3 p, - gauge pressure : The effective pressure,
relative to atmospheric pressure. The head corresponding to
3.2.3.9 y - specific energy : The energy per unit mass of
this pressure is
liquid. lt is given by the equation
6
Y=gH
Pg
3.2.3.10 HJ’ - loss of total head at inlet : The differente
Its value is
between the total head of the liquid at the measuring Point,
- positive if this pressure is greater than the atmospheric
or possibly of the liquid without velozity in the suction
pressure;
chamber, and the total head of the liquid in the inlet
section of the pump.
-
negative if this pressure is less than the at mospheric
pressure.
3.2.11 H,, - loss of total head on delivery : The differente
between the total head of the liquid in the outlet section of
3.2.3.4 velocity head : The kinetic energy per unit weight
the pump, and the total head of the liquid at the measuring
of the liquid in movement. lt is expressed by :
Point.
V2
3.2.3.12 (NPSH) - net positive suction head : The total
2g
inlet head, plus the head corresponding to the atmospheric
where v is the mean velocity of the liquid in the section
pressure, minus the head corresponding to the vapour
consid ered.
pressure :
(NPSH) = N, +s--
3.2.3.5 total head : In any section, the total head is given
Pg Pg
by :
Thus (NPSH), as well as inlet total head, is referred to the
V2
reference plane.
z+- p+-
Pg 2s
lt is necessary to make a distinction between
This is rela ted to atmosphere. The absolute total head in
-
the (NPSH) required at given flow and Speed of
any section is given by :
rotation for a given pump; it is specified by the manu-
facturer;
V2
p +pb+-
z+-
Pg Pg 2s -
the (NPSH) available for the same flow which is
determined by the installation.
3.2.3.6 Hl - inlet total head : The total head in the
-
the value (NPSH) determined during the cavitation-
inlet section of the pump :
test. This value is that which Causes in the first Stage a
drop of (3 + K/2) % in total head of the first Stage or in
z
Pl vl
efficiency at a given rate of flow, or in a rate of flow or
=z, +--i--
4
P’g 2s
efficiency at a given total head.
5

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ISO 35554977 (E)
Subscripts may be used to differentiate these quantities 4 GUARANTEES
(for example (NPSH), when the required value is concerned
4.1 Subjects of guarantees
and (NPSH)B, when the available value is concerned).
One or more of the following quantities may be guaranteed
by the manufacturer under the specified conditions and
3.2.4 Power
Speed of rotation :
3.2.4.1 P,
- pump power output : The power transferred
to the liquid at its passage through the pump : a) total head of the pump, HG, at the agreed flow rate
qvG, or flow rate of the pump qvG at the agreed total
= q,gH = qyJ = PQ,SH
PLI
head HG (see 9.4.1);
-
efficiency of the pump or Combi
b) power in put or
3.2.4.2 P, - pump power input : The power measured at
lint;
pump-motor unit at the guaranteed qvG HG
PO
the pump coupling.
at the agreed flow rate
c) NPSH required by the
Pump
3.2.4.3 P,, - motor power input : The power absorbed by
q
“G;
the pump driver.
d) other Points of the g,H curve may be indicated by
guaranteeing the total head at a reduced or increased
3.2.5 Efficiency
flow rate, in which case separately agreed increased
tolerantes will apply.
3.2.5.1 r) - pump efficiency :
Pump power output 4.2 Other conditions of guarantee
rl=
Pump power input
Unless specifically agreed otherwise in the contract, it shall
be taken that the following conditions apply to the
3.2.5.2 37int - transmission efficiency (shafting, coupling,
guarantee values :
gears, etc.) :
a) unless the Chemical and physical properties of the
Pump power input
liquid are stated, it shall be taken that the guarantee
Qint =
Points apply to clean cold water;
Power at motor shaft
b) the relation between the guarantee values under
3.2.5.3 qmot - motor efficiency :
clean cold water conditions and the likely Performance
under other liquid conditions shall be agreed in the
Power at motor shaft
contract;
rl =
mot
Motor power input
c) guarantees shall apply only to the pump as tested by
the methods and in the test arrangements specified, in
3.2.5.4 qgr -
Overall eff iciency :
this International Standard;
d) th e pump manufacturer shall not be responsible for
the sp lecification of the guarantee Point.
4.3 Fulfilment of guarantee
3.2.6 Type number K
The nominated guarantee for any quantity shall be deemed
to have been met if, when tested according to this
The type number, a dimensionless quantity, is defined by
International Standard, the measured Performance falls
the following formulal) :
within the tolerante specified in clause 9 for the particular
quantity. Other Points on the q,H curve shall not be
2 7113 (q’,)“*
K- guaranteed unless the Points and tolerantes for fulfilment
(gH’) 3’4
of guarantee are agreed in the contract.
where
5 TESTS
is the volume rate of flow per eye;
Qr ”
5.1 Organkation of tests
H’ is the head per Stage.
5.1 .l Place of testing
NOTE - Attention is drawn to the fact that, in this International
Standard, the type number applies to the guaranteed flow rate,
Acceptance tests shall be carried out at the manufacturer’s
which is not in conformity with common practice where K is
works, or alternatively at a place to be mutually agreed
calculated from the flow rate corresponding to the maximum
efficiency . between the manufacturer and the purchaser.
w q’,1/2
1) This formula is the same as the basic formula K =-
13/4
Y

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ISO 3555-1977 (E)
The evaluation of the test results, including graphical
5.1.2 Time of testing
plotting of the pump Performance curve, shall be made as
The time of testing shall be mutually agreed by the manu-
far as possible while the tests are in progress and, in any
facturer and the purchase r.
case, before the installation and instrumentation are
dismantled in Order that suspect measurements tan be
When tests are not carried out in the manufacturer’s works,
repeated without delay.
time shall be allowed for preliminary adjustments by both
the manufacturer and the installer.
5.1.3 Staff
5.2 Test arrangements
Accurate measurements depend not only on the quality of
the measuring instruments used but also on the ability and
skill of the persons operating and reading the measuring
5.2.1 Standard test arrangemen ts
devices during the tests. The staff entrusted with effecting
the measurements must be selected just as carefully as the
All practical Steps shall be taken to ensure that flow through
instruments to be used in the test.
the measuring section shall result in
Specialists with adequate experience in measuring operations
a) an axially symmetric velocity distribution;
in general shall be charged with operating and reading
b) a uniform static pressure distribution;
complicated measuring apparatus. Reading simple measuring
devices may be entrusted to such helpers who - upon short
freedom from swirl induced by the installation.
4
Prior instruction -
tan be assumed to effect the readings
with proper care and the accuracy required.
Some methods for ensuring these conditions for Standard
test arrangements are suggested below.
A chief of tests shall be appointed, possessing adequate
Acceptance tests may be carried out under Standard test
experience in measuring operations. Normally, when the
conditions for Pumps where the type number is less than
test is carried out at the manufacturer’s works, the chief
of tests is a staff member of the manufacturing firm. or equal to 1,5.
When the type number is greater than 1,5, it must be agreed
All persons charged with effecting the measurements are
contractually that the results of such tests will be held to
subordinated during the tests to the chief of tests, who
apply only to specified conditions. The purpose of such
conducts and supervises the measurements, reports on test
tests will be to provide an assurance that the pump will, if
conditions and the results of the tests and then drafts the
suitably installed, perform the specified duty.
test report. All questions arising in connection with the
measurements and their execution are subject to his
lt is recommended that for Standard test circuits leading
decision.
from reservoirs with a free surface, or from large stilling
vessels in a closed cicuit, the inlet straight length L shall be
The Parties concerned shall provide all assistance that the
determined by the expression :
chief of tests considers necessary.
L
D=K+5
5.1.4 Test Programme
Only the guaranteed operational data shall form the basis of
where D is the pipe diameter.
the test; other data determined by measurement during the
tests shall have merely an indicative (informative) function This expression is also valid for an arrangement that
and it shall be so stated if they are included in the includes, at a distance L upstream, a simple medium-radius
Programme. right angle bend that is not fitted with guide vanes. Under
these conditions, flow straighteners are not necessary in the
pipe between the bend and the pump.
5.1.5 Testing equipmen t
However, in a closed circuit where there is neither a reservoir
The chief of tests shall be responsible for the selection and
nor a stilling vessel immediately upstream of the pump, it is
Operation of measuring equipment. All of the measuring
necessary to ensure that the flow into the pump is free
equipment shall be covered by reports showing, by calibra-
from swirl induced by the installation and has a normal
tion or by comparison with other International Standards,
symmetrical velocity distribution.
that it camplies with the requirements of 5.4. These reports
shall be presented if required.
Significant swirl tan be avoided by :
-
careful design of the test circuit upstream of the
5.1.6 Test reports
measurement section;
All test records and record Charts shall be initialled by the
- judicious use of a flow straightener;
chief of tests and by the representatives of both the
-
suitable arrangement of the pressure tappings to
purchaser and the manufacturer, each of whom shall be
minimize their influence on the measurement.
provided with a copy of all records and Charts.
7

---------------------- Page: 11 ----------------------
603555~1977 (E)
5.2.2 Simula ted fest arrangemen ts
5.2.3 Pumps tested with fittings
When Pumps are tested under simulated site conditions
If specified in the contract, Standard tests tan be carried
flow straighteners shall not be installed immediately before out on a combination of a pump and :
the pump. lt is important that the characteristics of flow
1) associated fittings at the final site installation; or
to the simulated circuit should be controlled; that the flow
should, as far as possible, be free from significant swirl
2) an exact reproduction thereof; or
induced by the installation and have a symmetrical velocity
distribution. If necessary, the velocity distribution of the
3) fittings introduced for testing purposes and taken as
flow into the simulated circuit shall be determined by
forming part of the pump itself (see for example 5.2.4,
careful pitot tube traverses, in Order to establish that the
5.2.5, etc.).
required flow characteristics exist. If not the required
characteristics tan be obtained by the installation of
Connection on the inlet and outlet sides of the whole
suitable means, such as the Zanker flow straightener (see
combination shall be made in accordance with 6.2.2.
figure 1); but care must be taken to ensure that the
conditions of test will not be affected by the high,
irrecoverable pressure losses associated with efficient
Measurements shall then be taken in accordance with
straightening devices.
5.3.2.2 and 5.3.2.3.
d/D =
0,139
FIGURE 1 - Zanker fiow straightener

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ISO 35554977 (E)
5.2.4 Pumping ins talla tion under submerged conditions variations Those changes in value which take place
between o ne reading and the next.
Where a pump, or a combination of a pump and its fittings,
is tested or installed in conditions where the Standard pipe
5.3.2.2 P ERMISSIB LE OSCILLATIONS IN READINGS
connection on either inlet or outlet as described in 6.2.2,
AND USE OF DAMP ING
cannot be made owing to inaccessibility or submergence,
measurements shall be taken in accordance with 6.2.1.6.
Where the construction or Operation of a pump is such that
oscillations of great amplitude are present, measurements
5.2.5 Borehole and deep-Welf Pumps
may be carried out by means of an instrument capable of
providing an integration over at least one complete cycle
Borehole and deep-weil Pumps cannot usually be tested
of oscillation. The calibration of such an instrument shall
with their complete’ lengths of delivery main and,
comply with the provisions of the appropriate clauses.
consequently, the loss of head in the portions omitted, and
the power absorbed by any shafting therein, cannot be
Restricted damping may be introduced in measuring
measured. Any thrust bearing, would also be more lightly
instruments and their connecting lines where necessary to
loaded during the test than it would be in the final installa-
reduce the amplitude of oscillations to within the values
tion. (See 6.2.1.6.)
given in table 4.
5.2.6 Self-priming Pumps
TA BLE 4 - Maximum permissible amplitude of oscillations
percentage of mean value of 4
uantity being measu red
In principle the priming ability of self-priming Pumps shall
always be verified at the contractual static suction head
Maximum permissible
with the attached inlet piping equivalent to that in the final
Measured quantity amplitude of oscillations
installation. When the test cannot be carried out in the
%
described manner
...