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Rules for Classification and Construction

VI Additional Rules and Guidelines

5 Pumps

1 Guidelines for the Design, Construction and Testing of Pumps

Edition 2007


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The following Guidelines come into force on July 15 th, 2007

Germanischer Lloyd Aktiengesellschaft

Head OfficeVorsetzen 35, 20459 Hamburg, Germany

Phone: +49 40 36149-0Fax: +49 40 36149-200

[email protected]

www.gl-group.com

"General Terms and Conditions" of the respective latest edition will be applicable(see Rules for Classification and Construction, I - Ship Technology, Part 0 - Classification and Surveys).

Reproduction by printing or photostatic means is only permissible with the consent ofGermanischer Lloyd Aktiengesellschaft.

Published by: Germanischer Lloyd Aktiengesellschaft, HamburgPrinted by: Gebrder Braasch GmbH, Hamburg


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Section 1

General

A. Scope

The following Guidelines apply to the design, construc-tion and testing of pumps for the handling of liquids.

The application of these Guidelines covers pumps whose capacity in accordance with the GL-Rules I Ship Technology, Part 1 Seagoing Ships, Chapter 2 Ma-chinery Installations, Section 11, D. have to be verified in the manufacturer's works as well as pumps and mo-tors of hydraulically operated systems in accordance with Chapter 2 Machinery Installations, Section 14 . These Guidelines may be similarly applied to other

pumps as appropriate.

B. Definition

For the purpose of these Guidelines, liquid pumps in-clude:

rotodynamic pumps

side channel pumps

rotary and oscillating positive displacement pumps

liquid ejectors

For pumps of other designs, the requirements are to beagreed on a case to case basis.

C. Documents to be SubmittedIn the case of pumps for handling liquid gases, dan-gerous chemicals and liquid foodstuffs, sectionaldrawings together with details relating to the proposedmaterials and operating conditions are to be submittedin triplicate to the GL Head Office for approval.

Approval of drawings is not normally required forother pumps.

In individual cases and depending on the design andapplication the Society does, however, reserve theright to call for the documentation necessary to anassessment of the pump in question.

VI - Part 5GL 2007

Section 1 General Chapter 1Page 11

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Section 2

Design and Construction Principles

A. Materials

1. Approved materials

The materials of the pump components shall be suitable for the proposed applications. They are to be selected with due regard to the operating conditions and the na-ture of the liquid to be handled. The Rules for Materials issued by GL are to be observed. These Rules apply analogously to pressurized parts attached to the pumps.

Where the working temperature (t zul) of the liquid to be pumped is 10 C, the choice of materials is subject to the requirements of GL-Rules II Materialsand Welding, Part 1 Metallic Materials, Chapter 2 Steel and Iron Materials .

Where dangerous chemicals are to be pumped, evi-dence is to be supplied to GL attesting the suitabilityof the materials used.

2. Requirements on material manufacturers

Casings for pumps intended to be used for piping

systems of pipe class 1

I and II shall be manufactured by GL approved manufacturers. For the use in pipeclass III piping systems an approval according to otherrecognized standards may be accepted.

3. Limits on the application of materials forpump casings

3.1 Cast iron with lamellar graphite (at leastEN-GJL-200)

max. allowable working temperature t zul 200 C

max. allowable working pressure p e,zul 16 bar

Limitations:

a) for boiler water p e,zul 10 bar

b) for liquid fuels, lubricating oil, t zul 60 Cand for flammable hydraulic p e,zul 7 barfluid

Not permitted:

a) for casings of circulating pumps for heat-transfer oil

b) for casings of pumps for handling of dangerouschemicals

1 See GL-Rules I Ship Technology, Part 1 Seagoing Ships,

Chapter 2 Machinery Installations, Section 11, Table 11.1.

3.2 Nodular cast iron (Elongation A 5 at least12 %)

max. allowable working temperature t zul 300 C fornodular cast iron in normal qualitymax. allowable working temperature t zul 350 C fornodular cast iron in special quality according to GLRules II Materials and Welding, Part 1 MetallicMaterials, Chapter 2 Steel and Iron Materials, Sec -tion 5 , acceptable for casings of circulating pumps for

heat-transfer oil

3.3 Steel and cast steel for general applications

max. allowable working temperature t zul 300 C

3.4 Cast copper alloys

max. allowable working temperature t zul 200 C forcopper and aluminium brass,

max. allowable working temperature t zul 300 C forcopper nickel alloys

3.5 Aluminium casting alloys

max. allowable working temperature tzul 200 C withthe approval of the GL.

3.6 Plastics

The use of plastics requires the approval of GL in theindividual case of application.

4. Casing repairs

Casting defects in pump casings may be repaired only by recognized methods. The GL-Surveyor is to benotified prior to the execution of the repair.

B. Protection Against Excessive Pressure

1. Rotodynamic pumps must be so designed thatthey can be operated for a short time without damageeven with the discharge line closed.

2. Positive displacement pumps must be pro-tected against excessive pressure increases in the

pump casing by fitting relief valves which cannot be

adjusted to the closed position.

3. Pumps which do not clearly conform to one of these two designs must comply with requirement 1. or 2.

VI - Part 5GL 2007

Section 2 Design and Construction Principles Chapter 1Page 21

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C. Rated Output of Prime Mover

1. General requirements

The rated output of the prime mover is to be deter-

mined in such a way as to ensure the reliable operationof the pump under all anticipated operating conditions.It is required to be compatible with the mode of opera-tion, the characteristic curve of the pump and with the

properties of the liquid to be pumped.

2. Prime movers for rotodynamic pumps

By the way of a guide, the following values can, forexample, normally be regarded as adequate in the caseof rotodynamic pumps intended for operation inclosed piping systems, e.g. fresh cooling water sys-tems, brine systems, thermal oil systems:

Rated power of pumpP N [kW]

Rated power ofprime mover

P M [kW]

up to 10up to 50over 50

> 1,2 P N

1,2 1,1 P N

1,1 P N

Prime mover for pumps intended for operation in open piping systems, e.g. fire and emergency fire systems, ballast and bilge systems shall be rated for the entirecapacity range of the pump. Unrestricted operation is

to be ensured including direct (non throttled) dis-charge over board at maximum inlet head (max.draught). The rated output of the prime mover shallinclude a reserve power of not less than 10 %.

3. Prime movers for positive displacement pumps

Prime movers of positive displacement pumps shall berated for short circuit operation at maximum viscosity,i.e. the total flow is returned to the suction side via therelief valve.

D. Branches, Connections

As far as possible, inlet and outlet branches shall bedesigned for the same rated pressure.

Pipe connections are to be executed in such a mannerthat no unpermissible forces and moments are exertedon the pump.

E. Circulating Pumps for Heat-Transfer Oil

The shaft sealing of circulating pumps for heat-transfer oil must be so designed that oil leakage cannotoccur in an unacceptable manner and unacceptableleakage rate.

For shaft seals and/or bearings fitted with a coolingsystem the circulation flow is to be monitored.

F. Emergency Fire Pumps

Emergency fire pumps shall be of self-priming type or be equipped with additional suction aid.

For emergency fire pumps installed above the waterline in light condition of the ship, the NPSH 2 of the

pump (NPSH req) should be about 1 m lower than the NPSH value of the plant (NPSH

a). Details for deter-

mining NPSH a are given in Fig. 2.1 .

2 NPSH = Net Positive Suction Head, see also EUROPUMP:

NPSH on Rotodynamic Pumps European Committee of PumpManufacturers or ISO 9906

Chapter 1Page 22

Section 2 Design and Construction Principles VI - Part 5GL 2007

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Fig. 2.1 Calculation of NPSH a for emergency fire pumps which are installed above the waterline in light condition

VI - Part 5GL 2007

Section 2 Design and Construction Principles Chapter 1Page 23

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Section 3

Testing

A. Testing of Materials

1. The following are subject to material testingand certification in accordance with GL Rules:

casings of boiler water circulating pumps with a permitted working pressure of p e,zul 10 bar

casings of pumps for handling liquids with aworking temperature of t

zul 10 C

casings of pumps for handling dangerous chemi-cals

2. For all other pumps, the casing materials may be attested by a test report 2.2 according to EN 10204.The same procedure is also to be applied to the mate-rials used for rotating components.

3. Type and scope of non-destructive materialtests are to be agreed between the pump manufacturerand the foundry appropriate to the application re-

quirements, for example, in case of pumps handlingchemicals or liquid gases.

B. Pressure Testing

1. All pump components exposed to internal pressure (casing, cover, seal plate) are to be subjectedto a hydrostatic pressure test.

The following test pressure p p at least is to be applied:

p p = 1,5 p e,zul where p e,zul 200 barsubject to a minimum of p p = 4 bar

p p = p e,zul + 100 bar where p e,zul > 200 bar

pe,zul = maximum allowable working pressure

1.1 In the case of rotodynamic pumps, the maxi-mum allowable working pressure p e,zul is equal to thesum of the pressure in the suction branch and themaximum pressure difference according to the pumpcharacteristic.

1.2 In case of positive displacement pumps, themaximum allowable working pressure p e,zul is equalto the pressure which occurs on the discharge sidewhen the total flow is returned to the suction side via

the relief valve. The maximum pressure at the suction branch shall be considered.

2. For the purpose of hydrostatic pressure test-ing, pump casings shall not be painted on their internalor external surfaces.

C. Performance Testing

1. The following pumps are subject to finalinspection and to hydraulic performance testing in themanufacturer's works under the supervision of a GL-Surveyor:

bilge pumps / bilge ejectors

ballast pumps

seawater cooling pumps

fresh water cooling pumps

cooling pumps for fuel injection valves

fire pumps

emergency fire pumps

condensate pumps

boiler feedwater pumps

boiler water circulating pumps

lubricating oil pumps

fuel oil booster and transfer pumpscirculating pumps for heat-transfer oil

brine pumps

refrigerant circulating pumps

cargo pumps

hydraulic pumps for controllable pitch propel-lers

Other hydraulic pumps / hydraulic motors, see GLRules I Ship Technology, Part 1 Seagoing Ships,Chapter 2 - Machinery Installations, Section 14

2. The following contractually agreed operatingdata are to be verified during the performance test:

VI - Part 5GL 2007

Section 3 Testing Chapter 1Page 31

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Volume rate of flow 1 Q [m 3/h]

Delivery head H [m]

Pump power input P [kW]

Speed of rotation n [min -1]

3. As a standard procedure the hydraulic per-formance test shall be performed on manufacturer'stest bench. The procedure followed shall be based onrecognized national or international Standards andRegulations, such as:

DIN EN ISO 9906 Rotodynamic pumps Hydraulic performance acceptance test grade 2

VDMA 24 284 Testing of positive displace-ment pumps General regulations for testing

If the contract provides for a performance test in ac-cordance with one of the aforementioned standards ora comparable regulation the pump manufacturer is

bound to hold the said standard available for consulta-tion during the performance test.

4. If the performance test is conducted without the corresponding prime mover but with a test bench motor, deviations from the nominal speed of rotation n N may result which can be tolerated within specific limits. In case of rotodynamic pumps, the speed of rotation during testing shall be in line with ISO 9906. Accordingly, the speed of rotation during testing shall be within the range 50 % and 120 % of the specified speed. In order to trans-late the performance data Q, H and P measured at test speed n to the corresponding values for the specified speed n N, the following equations may be applied:

N N

nQ Q

n

=

;2

N N

nH H

n

=

;3

N N

nP P

n

=

5. For positive displacement pumps, the permis-sible deviations call for special agreement dependingon the design involved.

6. Conversion of the measured power input P tothe nominal power input P N is also required where the

power input is measured with a liquid which differs asregards density and/or viscosity from the liquid speci-fied in the contract 2

7. Where the contract calls for verification ofthe NPSH value, an approximation formula is to beagreed between customer and supplier to enable theconversion to be made if the test speed differs fromthe nominal speed.

1

The volume rate of flow is defined as the usable volume ratewhich is delivered by the pump through its outlet cross-section(pressure socket).

2 The effect of viscosity on the characteristic of pumps is shownin Figure 3.1.

8. Where pumps subject to mandatory testingare hydraulically driven, the corresponding hydraulicmotors and hydraulic pumps are to undergo a per-formance test, unless the pump is performance-testedin conjunction with the entire unit.

D. Other Tests

1. On positive displacement pumps the settingand correct dimensioning of the relief valve is to bechecked. Generally, the set pressure, the opening pres-sure and the reseating pressure shall be measured anddocumented. Where a positive displacement pump issupplied without a relief valve, this point is to benoted in the Test Certificate.

2. With self-priming rotodynamic pumps aswell as for rotodynamic pumps with attached or built-in suction aid, the functioning of the air intake stage isto be included within the scope of performance test.

3. During the performance test, the pump is to be checked for smooth running 3 and bearing tempera-ture.

4. Where the performance test is carried out onthe entire unit comprising the pump, coupling, primemover and common baseplate, the alignment of the

unit is to be checked. The fact that the test has been performed on the entire unit is to be noted in the TestCertificate.

5. In case of performance testing of bilge ejec-tors the pressures shall be within 3 % of the nominaldata. The resulting flow at the suction side may notdeviate by more than 5 %. Higher volume rate offlows are permitted.

E. Test Documents

1. The documents required for the various testsshall be supplied by the pump manufacturer to theSurveyor in good time and at the latest at the time ofcarrying out the tests.

2. A GL Test Certificate is to be issued showingthe results of the tests. Where the extent of the testsgoes beyond that specified by GL, the GL Test Cer-tificate may be supplemented by the pump manufac-turer's own test report.

3 The assessment may be based on VDI Regulation 2056 "Crite-

ria for the assessment of mechanical vibration in machines" oron a comparable standard.

Chapter 1Page 32

Section 3 Testing VI - Part 5GL 2007

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Fig. 3.1 Effect of viscosity on pump characteristic

VI - Part 5GL 2007

Section 3 Testing Chapter 1Page 33

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Annex A

Illustration of Principles of Pumps

Note

The following illustrations of the principles of pumpstogether with the appropriate terminology have beentaken from volume 1 of the EUROPUMP Techni-cal Dictionary with the agreement of the European

Committee of Pump Manufacturers. In the context ofthe present Regulations, it is hoped that this in-

formation complied by the European pump industrywill contribute to the clear identification of pumptypes.

Fig. A.1 Illustrations of the principles of rotodynamic pumps and side channel pump

VI - Part 5GL 2007

Annex A Illustration of Principles of Pumps Chapter 1Page A1


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Fig. A.2 Illustrations of principles of positive-rotary pumps

Chapter 1Page A2

Annex A Illustration of Principles of Pumps VI - Page 5GL 2007


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Fig. A.3 Illustrations of the principles of reciprocating pumps

VI - Part 5GL 2007

Annex A Illustration of Principles of Pumps Chapter 1Page A3


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Fig. A.4 Illustrations of the principles of other pumps

Chapter 1Page A4

Annex A Illustration of Principles of Pumps VI - Page 5GL 2007

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