SIST-TP ISO/TR 11071-2:2012
Comparison of worldwide lift safety standards - Part 2: Hydraulic lifts (elevators)
Comparison of worldwide lift safety standards - Part 2: Hydraulic lifts (elevators)
This Technical Report consists of a comparison of the requirements of selected topics as covered by the following worldwide safety standards (excluding regional or national deviations): a) CEN European Standard EN 81-2:1998, Safety rules for the construction and installation of lifts - Part 2: Hydraulic lifts; b) ASME A17.1:2004, Safety Code for Elevators and Escalators and CSA B44:2004, Safety Code for Elevators; c) Japan;Building Standard Law of Japan (BSLJ); d) Standards Australia: AS 1735-1:2003, Lifts, Escalators and Moving Walks - Part 1: General Requirements; AS 1735-3:2002, Lifts, Escalators and Moving Walks - Part 3: Passenger and Goods Lifts - Electro-hydraulic. This Technical Report applies to hydraulic lifts only, both of the direct and indirect acting type. It should be noted that, in addition to the above listed standards, lifts must conform to the requirements of other standards (for example, standards covering mechanical, structural, and electrical equipment; building codes, and environmental regulations).
Comparaison des normes mondiales de sécurité des ascenseurs -- Partie 2: Ascenseurs hydrauliques
Primerjava svetovnih standardov za varnost dvigal (liftov) - 2. del: Hidravlična dvigala (lifti)
To tehnično poročilo zajema primerjavo zahtev izbranih tem iz naslednjih svetovnih varnostnih standardov (brez regionalnih ali nacionalnih odstopanj): a) CEN – evropski standard EN 81-2:1998, Varnostna pravila za konstruiranje in vgradnjo dvigal (liftov) – 2. del: Hidravlična dvigala; b) ASME A17.1:2004, Safety Code for Elevators and Escalators (Varnostni predpisi za dvigala in tekoče stopnice) ter CSA B44:2004, Safety Code for Elevators (Varnostni predpisi za dvigala); c) japonska zakonodaja s področja standardov v gradbeništvu – BSLJ; d) avstralska standarda: AS 1735-1:2003, Lifts, Escalators and Moving Walks - Part 1: General Requirements (Dvigala, tekoče stopnice in steze – 1. del: Splošne zahteve); AS 1735-3:2002, Lifts, Escalators and Moving Walks - Part 3: Passenger and Goods Lifts - Electro-hydraulic (Dvigala, tekoče stopnice in steze – 3. del: Osebna in tovorna dvigala – elektrohidravlična). To tehnično poročilo se uporablja samo za hidravlična dvigala neposrednega in posrednega tipa delovanja. Dvigala morajo biti skladna z zgoraj navedenimi standardi ter zahtevami drugih standardov (na primer standardi, ki zajemajo mehansko, strukturno in električno opremo, gradbenimi ter okoljskimi predpisi).
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TECHNICAL ISO/TR
REPORT 11071-2
Second edition
2006-04-15
Comparison of worldwide lift safety
standards —
Part 2:
Hydraulic lifts (elevators)
Comparaison des normes mondiales de sécurité des ascenseurs —
Partie 2: Ascenseurs hydrauliques
Reference number
ISO/TR 11071-2:2006(E)
©
ISO 2006
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ISO/TR 11071-2:2006(E)
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ii © ISO 2006 – All rights reserved
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ISO/TR 11071-2:2006(E)
Contents Page
Foreword. iv
Introduction . v
1 Scope . 1
2 Terminology . 1
3 Basis for lift safety standards development (basic assumptions) . 5
4 Approach to design safety for hydraulic components . 13
5 Driving Machines and jacks (plungers and cylinders). 33
6 Valves, Piping and Fittings . 44
7 Ropes and chains . 59
8 Capacity and loading. 65
9 Spaces and clearances . 75
10 Protection against free-fall, excessive speed and creeping . 78
11 Electrical devices. 83
Annex A (informative) Tabulations . 88
Annex B (informative) References. 113
Annex C (informative) CEN/TC10/WG1 N99. 115
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ISO/TR 11071-2:2006(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established 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. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
In exceptional circumstances, when a technical committee has collected data of a different kind from that
which is normally published as an International Standard (“state of the art”, for example), it may decide by a
simple majority vote of its participating members to publish a Technical Report. A Technical Report is entirely
informative in nature and does not have to be reviewed until the data it provides are considered to be no
longer valid or useful.
ISO/TR 11071-2 was prepared by Technical Committee ISO/TC 178, Lifts, escalators and moving walks.
This second edition cancels and replaces the first edition (ISO/TR 11071-2:1996), and amendment 1
(ISO/TR 11071-2:1996/Amd. 1:1999), which have been technically revised.
ISO/TR 11071 consists of the following parts, under the general title Comparison of worldwide lift safety
standards:
⎯ Part 1: Electric lifts (elevators)
⎯ Part 2: Hydraulic lifts (elevators)
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ISO/TR 11071-2:2006(E)
Introduction
Introduction to 1996 edition
At the 1981 plenary meeting of ISO/TC 178, work was started on a comparison of CEN standard EN 81/1 with
the American, Canadian, and USSR lift safety standards. In 1983, Working Group 4 was officially formed to
carry out the task of preparing cross reference between the relevant sections of these standards and to
analyze the differences on selected subjects. The goal at that time was to prepare a technical report which
would provide reference information to assist national committees when reviewing and revising individual
standards which may initiate a gradual convergence of the technical requirements. In 1984, the study was
expanded to include the Council for Mutual Economic Assistance (CMEA) safety standard. That report,
ISO/TR 11071-1, Comparison of worldwide lift safety standards — Part 1: Electric lifts (elevators), was
published 1990-12-01.
In 1989, the charge to WG 4 was expanded to include hydraulic lifts. Since there was no standard for
hydraulic lifts in the Russian Federation, and the CMEA standard was being phased out of use, this Part 2 of
the comparison is generally limited to the ASME, CEN, and CSA standards. The Japan Elevator Association
was invited to add their standards to this comparison, however, no response to this request was received.
This report is intended to aid standards writers in developing their safety requirements, and to help standard
users understand the basis for the requirements as they are applied throughout the world.
This report is not intended to replace existing safety standards. Conclusions are arrived at in some cases, but
only where there is unanimity amongst the various experts. In other cases, the reasons for the divergent views
are expressed.
This report must be read in conjunction with the various safety standards, as it was often necessary to
summarize the requirements for the sake of clarifying the comparisons. Further, the information contained in
this report does not necessarily represent the opinions of the standards writing organizations responsible for
the development of the safety standards which are being compared, and they should be consulted regarding
interpretations of their requirements (see Annex B).
Introduction to this edition
After the original publication (1996) of this technical report, including American, Canadian and European data
and thereto Supplement 1 (1999-08-01), which added Australian and Japanese data, has been revised or
amended. The recommendations in the form of “agreed upon points” stated in the first edition have also
affected the revisions of the national standards.
The original report and amendment have been widely used by lift industry and standards writing organizations,
including the ISO Technical Committee 178. Users have expressed need for an updated and consolidated
version of the document, in particular the comparison tabulations. With the Resolution 208/2002, the
ISO/TC 178 requested WG4 to consolidate original publications, including Supplements and “to update
comparison tables in ISO/TR 11071 with data from the most recently published standards for lifts and to
republish both documents, Part 1 and Part 2 with updated tables and with minimum changes to the narrative
sections”.
The narrative sections of the original publication, in particular assumptions, historical backgrounds,
observations and suggestions as well as the points agreed upon were the result of extensive work of the
ISO/TC 178 Working group 4. ISO/TC 178 is currently working on a new series of ISO documents under the
general title Safety requirements for lifts (elevators). In that process the updated comparison tables are being
used as reference. Extensive work on complete re-write of the narrative sections was not deemed necessary.
However, republication of the text with only minor editorial changes would help readers to understand the
background to the safety concerns being addressed in the current national standards. However, because of
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ISO/TR 11071-2:2006(E)
recent (2000) harmonization of ASME and CSA Codes, it was necessary to replace the quoted rule numbers
with those in the current Codes In most sentences the ASME and CSA. I some other cases quoted references
are updated in a NOTE following the narrative section or sentence.
All quoted requirement referenced in all tables (CEN, ASME/CSA, Japan and SA) are up to date.
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TECHNICAL REPORT ISO/TR 11071-2:2006(E)
Comparison of worldwide lift safety standards —
Part 2:
Hydraulic lifts (elevators)
1 Scope
This Technical Report consists of a comparison of the requirements of selected topics as covered by the
following worldwide safety standards (excluding regional or national deviations):
a) CEN European Standard EN 81-2:1998, Safety rules for the construction and installation of lifts — Part 2:
Hydraulic lifts;
b) ASME A17.1:2004, Safety Code for Elevators and Escalators and CSA B44:2004, Safety Code for
Elevators;
c) Japan - Building Standard Law of Japan (BSLJ);
d) Standards Australia:
⎯ AS 1735-1:2003, Lifts, Escalators and Moving Walks — Part 1: General Requirements;
⎯ AS 1735-3:2002, Lifts, Escalators and Moving Walks — Part 3: Passenger and Goods Lifts —
Electro-hydraulic.
This Technical Report applies to hydraulic lifts only, both of the direct and indirect acting type.
It should be noted that, in addition to the above listed standards, lifts must conform to the requirements of
other standards (for example, standards covering mechanical, structural, and electrical equipment; building
codes, and environmental regulations). Some of the standards will be referred to in this Technical Report.
2 Terminology
2.1 Lifts and elevators
2.1.1 The CEN term lift corresponds to the ASME and CSA term elevator. These terms are used
inter-changeably in this report.
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ISO/TR 11071-2:2006(E)
2.1.2 For the purposes of this report, unless otherwise specified, the terms passenger lift and freight lift
correspond to the following terms used in other Standards:
*
Term used in this
Correspond to terms used in the following standards
report
CEN ASME and CSA
Passenger lift Lift except goods passenger lift Passenger elevator & freight elevator
permitted to carry passengers
**
Freight lift Freight elevator
Goods passenger lift
* See the definitions in the applicable Standards.
**
This term is used only to enable comparisons to be made later in this report. It does not indicate recognition of the term “freight lift”
by CEN.
2.2 Hydraulic terminology
2.2.1 Difference
There are some notable differences in the standards respecting hydraulic lift terminology as shown in the
Table 1, Column A and B.
2.2.2 Agreed-upon points, re: hydraulic terminology
The differences should be eliminated or minimized through proposed changes to ASME and CSA Standards,
as shown in Table 1, Column D.
If approved by ASME and CSA Committees, the proposed changes would eliminate major differences
between CEN and North American Standards.
Column C gives the description of the equipment that a term (listed in Column A, B, or D) embraces.
In addition to “hydraulic machine”, ASME and CSA propose to introduce the term “hydraulic driving machines”
hydraulic driving machines”. The terms are needed to differentiate between “electric” and “hydraulic” driving
machines all covered in one ASME and CSA Standard. This is not necessarily applicable to CEN, as the
electric and hydraulic lifts are covered by two separate standards.
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ISO/TR 11071-2:2006(E)
2.2.3 Terminology in this report
In this report, the CEN terminology will be used, with the ASME and CSA terms in brackets if different.
Table 1 — Hydraulic Terminology
Column A Column B Column C Column D
CEN ASME & CSA Description Agreed upon points:
Current ASME & CSA proposed
changes
Direct acting Direct plunger — Direct acting hydraulic
a
elevator
hydraulic elevator
lift
Indirect acting Roped hydraulic — No change
Elevator
lift
b
Machine — Pump, motor, valves Hydraulic Machine
c
Jack Driving machine Cylinder and ram Hydraulic jack
Ram Plunger or piston — Plunger (ram) or piston
Base Head/bottom Cylinder end cap No change
(Includes plunger end
cap as well)
Valves:
Non-return Check — No change
Pressure relief Pump relief — No change
Direction Control — No change
Rupture ASME-Safety CSA-Rupture — No change
NOTE ASME and CSA adopted terms:
a
“direct-acting”.
b
“hydraulic machine".
c
“hydraulic jack”.
2.3 Working pressure vs full load pressure
ASME and CSA use working pressure (WP), which is defined as the pressure at the hydraulic driving machine
when lifting the car and its rated load at rated speed, or with class C2 loading, when leveling up with maximum
static load.
CEN defines full load pressure (FLP) as the static pressure exerted at the piping directly connected to the jack,
the car with the rated load being at rest at the highest landing level.
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ISO/TR 11071-2:2006(E)
CEN Annex K, clause K.1.1 recognizes that friction losses as a result of fluid flow are on the order of 15 %;
thus a factor of 1,15 is included in their factor of safety determination.
NOTE CEN reference to “Clause 12, NOTE 1” in this clause and through the 1996 edition of this document has been
replaced with reference to “Annex K, Clause K1.1” in this edition.
Thus, ASME WP = 1,15 x (CEN FLP).
2.4 Other terms
Additional terminology, where there is a difference between the CEN and the ASME and CSA standards, is
shown in Table 2:
NOTE Since ASME and CSA are now harmonized they will be shown through this edition in a column under title
“ASME and CSA” or “ASME/CSA”.
Table 2 — Terminology
CEN ASME and CSA
Docking operation Truck zone operation
Electric safety device Electrical protective device
Fixings Fastenings
Landing door Hoistway door
Mains Main power supply
Reeving ratio Roping ratio
Instantaneous safety gear Type A safeties (instantaneous safeties)
Progressive safety gear Type B safeties (progressive safeties)
Pulley Sheave
Safety gear Safeties
Well Hoistway
2.5 Abbreviations
The following abbreviations are used in this report:
FOS = Factor of safety or safety factor.
YP = Yield point.
WP = Working pressure.
UTS = Ultimate tensile strength.
FLP = Full load pressure.
NOTE See also list of abbreviations in item 4.1.2.
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ISO/TR 11071-2:2006(E)
3 Basis for lift safety standards development (basic assumptions)
3.1 Historical background
3.1.1 All lift safety standards assume certain things as being true, without proving them as such, and
stipulate safety rules that are based on these assumptions.
3.1.2 No standard, however, clearly spells out the assumptions used. The CEN committee analyzed its
standard and summarized in the document CEN/TC10/WG1 N99 (see Annex C) the assumptions that, in the
opinion of the committee, were used in the CEN standard.
3.1.3 The CEN assumptions were compared with assumptions implicitly built into other safety standards. It
has been indicated that:
a) some assumptions apparently used in the CEN standard were not listed in the document referred to in
CEN/TC10/WG1 N99;
b) some assumptions used in other standards differ from those in CEN/TC10/WG1 N99.
3.1.4 Using CEN/TC10/WG1 N99 as a model, the following list of assumptions (see 3.3 through 3.9 in this
report) has been developed, which could be used as a basis for future work on safety standards.
The CEN assumptions 5 (related to car speed) and 7 (related to restrictors) as listed in Annex C have not
been considered for adoption in this report, since they are deemed to be design parameters.
Further, CEN assumption 2 is adopted in this report as assumption 1 and CEN assumption 6 as assumption
3(c) in order to be consistent with Part 1 of this report.
In summary, CEN assumptions 1, 3, 4, 8, 9, and 10 correspond to assumptions 1, 2, 3, 4, 5, and 6 in this
report. Assumption 7 is not covered in the CEN document.
3.2 General
3.2.1 Listed in 3.3 through 3.9 (except as noted) are those things specific to lifts that are assumed as true,
although not yet proven or demonstrated as such, including:
a) functioning and reliability of lift components;
b) human behaviour and endurance; and
c) acceptable level of safety and safety margins.
3.2.2 Where the probability of an occurrence is considered highly unlikely, it is considered as not happening.
3.2.3 Where an occurrence proves that an assumption is false, it does not necessarily prove that all other
assumptions are false.
3.2.4 The assumptions should be subject to periodic review by standards writing organizations to ensure
their continuing validity – considering accident statistics, as well as such things as changes in technologies,
public expectations (e.g. product liability), and human behaviour.
3.3 Assumption 1 — safe operation assured to 125 % of rated load
Safe operation of lifts is assured for loads ranging from 0 to 100 % of the rated load. In addition, in the case of
passenger lifts (see 2.1.2), safe operation is also assured for an overload of 25 %; however, it is not
necessary to be able to raise this overload nor to achieve normal operation (rated load performance).
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ISO/TR 11071-2:2006(E)
3.3.1 Rationale for Assumption 1
3.3.1.1 All safety standards limit the car area in relation to its rated capacity (load and/or number of
persons) in order to minimize the probability of inadvertent overloading. However, it is recognized that the
possibility of an overloading of up to 25 % still exists on passenger lifts. To eliminate any hazard for
passengers, safe operation must be assured, but not necessarily normal operation.
3.3.1.2 In the case of freight lifts, no overloading is anticipated. It is assumed that designated attendants
and freight handlers will adhere to instructions posted in cars and will not overload them.
3.3.2 Assumption 1 as applied in current standards
3.3.2.1 Currently CEN does not specifically require a 25 % overload safety margin; however, the design
requirements provide for that level of safety.
ASME and CSA requirements 3.16 and 2.16.8 specifically require that safety be assured on passenger lifts in
the case of 25 % overload.
3.3.2.2 With exceptions given in 3.3.2.5, the ratio of the rated load to the car platform area for passenger
lifts is equal (± 5 %) in all standards for the range of 320 to 4 000 kg, and in that respect, universality of the
assumption #1 is achieved.
However, the assumed average weight of a passenger differs: 75 kg (CEN) and 72,5 kg (ASME and CSA).
3.3.2.3 Furthermore, the rated load to car platform area ratio is different for freight lifts.
2
CEN (non-commercial vehicle with instructed users) 200 kg/m
2
ASME/CSA (general freight Class A) 244/240 kg/m
2
(motor vehicle Class B) 146/145 kg/m
2
(industrial truck Class C) 244/240 kg/m
3.3.2.4 The CEN standard contains two tables showing the ratio between the rated load and the
maximum available car area (for passenger lifts), see Table 3.
The CEN Table “1.1” corresponding to the requirements for electric lifts is based on the rationale explained in
3.3.1.1 and was taken into consideration when formulating the statement in 3.3.2.2.
3.3.2.5 The CEN Table “1.1 A”, acceptable for Goods passengers lifts, is based on the rationale that
where there is a low probability of the car being overloaded with persons, the available area of a hydraulic lift
may be increased up to therein specified maximum, provided that additional safety measures are taken to
ensure the safe interruption in the lift operation. Such measures include:
a) a pressure switch to prevent a start for a normal journey when the pressure exceeds the full load
pressure by more than 20 %;
b) the design of the car, car sling, car-ram connection, suspension means, car safety gear, rupture valve,
clamping or pawl device, guide rails, and buffers must be based on a load resulting from CEN Table “1.1”;
c) the design pressure of the jack and the piping shall not be exceeded by more than 1,4.
Starting point for CEN Table “1.1A” was the comparison of safety factors of driving systems on electric traction
lifts versus hydraulic lifts. On hydraulic lifts the safety factor for the car suspension means and supporting
structure is at least 3 times higher than that of the traction driving systems, when friction between the
suspension ropes and the grooves of the drive sheave is taken into account. Consequently, the safety risk of
unintended car movement downwards due to the overloading on hydraulic lifts is significantly lower than on
electric traction lifts.
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ISO/TR 11071-2:2006(E)
Furthermore, assuming that the car weight is equal to the rated load, in that case an overload of x % on the
electric traction lift would correspond to only x/2 % overload for the hydraulic system.
NOTE This is true for machine power only; not for e.g. safety gear operation, guide rails dimensioning, etc.
2
For car areas up to 5 m , the required rated load in CEN Table “1.1 A” for a hydraulic lift may be 1,6 times less
than the rated load according to CEN Table 1.1.
NOTE 1.6 is an ISO-standard number R5. This is important in view of the rated loads according to ISO 4190-1 1999,
2
Lift (US: Elevator) installation — art 1: Class I, II, III and VI lifts, e.g. a Goods passengers lift with 5 m available car area
requires 2 500 kg rated load in the case of an electric lift, and 1 600 kg in the case of a hydraulic lift. For car areas bigger
2
than 5 m there is no mathematical background.
See Table 3 for an abbreviated comparison of the CEN Tables.
Table 3 — CEN Tables
Rated Load Maximum Car Area Increase in Car Area
"1.1 A" over "1.1"
CEN Table 1.1 CEN Table 1.1 A
for Goods passengers lifts
2 2
kg m m %
400 1,17 1,68 44
800 2,00 2,96 48
1 200 2,80 4,08 46
1 600 3,56 5,04 42
over 1 600, add N/A 0,40/100 kg N/A
2 000 4,20 6,64 58
2 500 5,00 8,84 73
over 2 500, add 0,16/100 kg 0,4/100 kg 250
3.3.2.6 Lift components that are normally designed to withstand, without permanent damage, overloads
greater than 25 % (such as ropes, guides, sheaves, buffers, disconnect switches) are not considered in this
comparison.
NOTE 3.3.2.6 CEN Assumption 2 (see Annex C) is not a new assumption, but rather one of the methods as to how
Assumption 1 is applied in the CEN standard.
3.4 Assumption 2 - failure of electric safety devices
The possibility of a failure of an electric safety device complying with the requirement(s) of a lift safety
standard is not taken into consideration.
Since national safety rules for lifts may be based on different assumptions (some are listed below),
universality of Assumption 2 may be questioned.
3.4.1 Rationale for Assumption 2
Reliability and safety performance of lift components designated as electric safety devices is assured if
designed in accordance with rules contained in a given lift safety standard. However, the design rules may be
based on different assumptions.
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ISO/TR 11071-2:2006(E)
3.4.2 Assumption 2 as applied in current standards
Most methods of assuring performance reliability of electric safety devices are similar in present standards.
There are, however, differences and inconsistencies, as detailed in section 11.
Section 11.1.3 deals in particular with discrepancies in assumptions implied in requirements for design of
electric safety devices.
3.5 Assumption 3 - failure of mechanical devices
a) With the exception of items listed below, a mechanical device built and maintained according to good
practice and the requirements of a standard comprising safety rules for lifts is assumed not to deteriorate
to the point of creating hazards before the failure is detected.
NOTE National practices and safety rules may be different, such as safety factors. See sections 4.1.3 and 4.2.1 of
this report;
b) the possibility of the following mechanical failures shall be taken into consideration:
1) rupture of car suspension means;
2) rupture and slackening of any connecting means such as safety related auxiliary ropes, chains and
belts where the safety of normal lift operation or the operation of a safety related standby component
is dependent on such connections;
NOTE Since 2000, overspeed valve is required by ASME and CSA when flexible hoses are used and
when elevator is located in seismic risk zones 2 or greater;
3) small leakage in the hydraulic system (jack included);
c) the possibility of a car or counterweight striking a buffer at a speed higher than the buffer's rating is not
taken into consideration;
d) the possibility of a simultaneous failure of a mechanical device listed above and another mechanical
device provided to ensure safe operation of a lift, should the first failure occur, is not taken into
consideration.
NOTE 1 The Working Group could not agree upon adopting the CEN Assumption 4.3 (see Annex C) requiring that “the
possibility of rupture in the hydraulic system (jack excluded) shall be taken into consideration”;
NOTE 2 Presently, this assumption is implemented only in CEN by requiring a rupture valve or similar devices, while
CSA assumes the rupture of flexible hoses only and in that case only, the rupture valve is required. In ASME, the
overspeed valve (safety valve) is only required in seismic risk zones 2 or greater.
NOTE 3 The CEN rupture valve protects only in the case of rupture of piping, not the cylinder. The USA's experience
indicates that most problems arise from the rupture of cylinders rather than piping;
NOTE 4 Refer to section 10 and table 12 in this Report for detailed comparison of requirements for free fall and
excessive speed protection.
3.5.1 Rationale for Assumption 3
3.5.1.1 Although recent accident records do not support the assumption in 3.5 (b)(1), most safety
standards (including those studied in the preparation of this report) still assume that the risk of suspension
means failure, in particular wire ropes and chains, exists.
3.5.1.2 With the assumption in 3.5 (b)(2) it is recognized that the listed components could deteriorate to
the point of creating a direct or potential hazard (by making a safety related standby component inoperative)
before the deterioration is detected.
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ISO/TR 11071-2:2006(E)
3.5.2 Assumption 3 as applied in current standards
3.5.2.1 CEN (9.5.1) clearly assumes failure of suspension means, while ASME and CSA requirement
3.17 imply that safety gear must be able
...
SLOVENSKI STANDARD
SIST-TP ISO/TR 11071-2:2012
01-oktober-2012
1DGRPHãþD
SIST ISO/TR 11071-2:1999
3ULPHUMDYDVYHWRYQLKVWDQGDUGRY]DYDUQRVWGYLJDO OLIWRY GHO +LGUDYOLþQD
GYLJDOD OLIWL
Comparison of worldwide lift safety standards - Part 2: Hydraulic lifts (elevators)
Comparaison des normes mondiales de sécurité des ascenseurs -- Partie 2: Ascenseurs
hydrauliques
Ta slovenski standard je istoveten z: ISO/TR 11071-2:2006
ICS:
91.140.90 'YLJDOD7HNRþHVWRSQLFH Lifts. Escalators
SIST-TP ISO/TR 11071-2:2012 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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SIST-TP ISO/TR 11071-2:2012
TECHNICAL ISO/TR
REPORT 11071-2
Second edition
2006-04-15
Comparison of worldwide lift safety
standards —
Part 2:
Hydraulic lifts (elevators)
Comparaison des normes mondiales de sécurité des ascenseurs —
Partie 2: Ascenseurs hydrauliques
Reference number
ISO/TR 11071-2:2006(E)
©
ISO 2006
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ISO/TR 11071-2:2006(E)
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Contents Page
Foreword. iv
Introduction . v
1 Scope . 1
2 Terminology . 1
3 Basis for lift safety standards development (basic assumptions) . 5
4 Approach to design safety for hydraulic components . 13
5 Driving Machines and jacks (plungers and cylinders). 33
6 Valves, Piping and Fittings . 44
7 Ropes and chains . 59
8 Capacity and loading. 65
9 Spaces and clearances . 75
10 Protection against free-fall, excessive speed and creeping . 78
11 Electrical devices. 83
Annex A (informative) Tabulations . 88
Annex B (informative) References. 113
Annex C (informative) CEN/TC10/WG1 N99. 115
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Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established 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. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
In exceptional circumstances, when a technical committee has collected data of a different kind from that
which is normally published as an International Standard (“state of the art”, for example), it may decide by a
simple majority vote of its participating members to publish a Technical Report. A Technical Report is entirely
informative in nature and does not have to be reviewed until the data it provides are considered to be no
longer valid or useful.
ISO/TR 11071-2 was prepared by Technical Committee ISO/TC 178, Lifts, escalators and moving walks.
This second edition cancels and replaces the first edition (ISO/TR 11071-2:1996), and amendment 1
(ISO/TR 11071-2:1996/Amd. 1:1999), which have been technically revised.
ISO/TR 11071 consists of the following parts, under the general title Comparison of worldwide lift safety
standards:
⎯ Part 1: Electric lifts (elevators)
⎯ Part 2: Hydraulic lifts (elevators)
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Introduction
Introduction to 1996 edition
At the 1981 plenary meeting of ISO/TC 178, work was started on a comparison of CEN standard EN 81/1 with
the American, Canadian, and USSR lift safety standards. In 1983, Working Group 4 was officially formed to
carry out the task of preparing cross reference between the relevant sections of these standards and to
analyze the differences on selected subjects. The goal at that time was to prepare a technical report which
would provide reference information to assist national committees when reviewing and revising individual
standards which may initiate a gradual convergence of the technical requirements. In 1984, the study was
expanded to include the Council for Mutual Economic Assistance (CMEA) safety standard. That report,
ISO/TR 11071-1, Comparison of worldwide lift safety standards — Part 1: Electric lifts (elevators), was
published 1990-12-01.
In 1989, the charge to WG 4 was expanded to include hydraulic lifts. Since there was no standard for
hydraulic lifts in the Russian Federation, and the CMEA standard was being phased out of use, this Part 2 of
the comparison is generally limited to the ASME, CEN, and CSA standards. The Japan Elevator Association
was invited to add their standards to this comparison, however, no response to this request was received.
This report is intended to aid standards writers in developing their safety requirements, and to help standard
users understand the basis for the requirements as they are applied throughout the world.
This report is not intended to replace existing safety standards. Conclusions are arrived at in some cases, but
only where there is unanimity amongst the various experts. In other cases, the reasons for the divergent views
are expressed.
This report must be read in conjunction with the various safety standards, as it was often necessary to
summarize the requirements for the sake of clarifying the comparisons. Further, the information contained in
this report does not necessarily represent the opinions of the standards writing organizations responsible for
the development of the safety standards which are being compared, and they should be consulted regarding
interpretations of their requirements (see Annex B).
Introduction to this edition
After the original publication (1996) of this technical report, including American, Canadian and European data
and thereto Supplement 1 (1999-08-01), which added Australian and Japanese data, has been revised or
amended. The recommendations in the form of “agreed upon points” stated in the first edition have also
affected the revisions of the national standards.
The original report and amendment have been widely used by lift industry and standards writing organizations,
including the ISO Technical Committee 178. Users have expressed need for an updated and consolidated
version of the document, in particular the comparison tabulations. With the Resolution 208/2002, the
ISO/TC 178 requested WG4 to consolidate original publications, including Supplements and “to update
comparison tables in ISO/TR 11071 with data from the most recently published standards for lifts and to
republish both documents, Part 1 and Part 2 with updated tables and with minimum changes to the narrative
sections”.
The narrative sections of the original publication, in particular assumptions, historical backgrounds,
observations and suggestions as well as the points agreed upon were the result of extensive work of the
ISO/TC 178 Working group 4. ISO/TC 178 is currently working on a new series of ISO documents under the
general title Safety requirements for lifts (elevators). In that process the updated comparison tables are being
used as reference. Extensive work on complete re-write of the narrative sections was not deemed necessary.
However, republication of the text with only minor editorial changes would help readers to understand the
background to the safety concerns being addressed in the current national standards. However, because of
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recent (2000) harmonization of ASME and CSA Codes, it was necessary to replace the quoted rule numbers
with those in the current Codes In most sentences the ASME and CSA. I some other cases quoted references
are updated in a NOTE following the narrative section or sentence.
All quoted requirement referenced in all tables (CEN, ASME/CSA, Japan and SA) are up to date.
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TECHNICAL REPORT ISO/TR 11071-2:2006(E)
Comparison of worldwide lift safety standards —
Part 2:
Hydraulic lifts (elevators)
1 Scope
This Technical Report consists of a comparison of the requirements of selected topics as covered by the
following worldwide safety standards (excluding regional or national deviations):
a) CEN European Standard EN 81-2:1998, Safety rules for the construction and installation of lifts — Part 2:
Hydraulic lifts;
b) ASME A17.1:2004, Safety Code for Elevators and Escalators and CSA B44:2004, Safety Code for
Elevators;
c) Japan - Building Standard Law of Japan (BSLJ);
d) Standards Australia:
⎯ AS 1735-1:2003, Lifts, Escalators and Moving Walks — Part 1: General Requirements;
⎯ AS 1735-3:2002, Lifts, Escalators and Moving Walks — Part 3: Passenger and Goods Lifts —
Electro-hydraulic.
This Technical Report applies to hydraulic lifts only, both of the direct and indirect acting type.
It should be noted that, in addition to the above listed standards, lifts must conform to the requirements of
other standards (for example, standards covering mechanical, structural, and electrical equipment; building
codes, and environmental regulations). Some of the standards will be referred to in this Technical Report.
2 Terminology
2.1 Lifts and elevators
2.1.1 The CEN term lift corresponds to the ASME and CSA term elevator. These terms are used
inter-changeably in this report.
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2.1.2 For the purposes of this report, unless otherwise specified, the terms passenger lift and freight lift
correspond to the following terms used in other Standards:
*
Term used in this
Correspond to terms used in the following standards
report
CEN ASME and CSA
Passenger lift Lift except goods passenger lift Passenger elevator & freight elevator
permitted to carry passengers
**
Freight lift Freight elevator
Goods passenger lift
* See the definitions in the applicable Standards.
**
This term is used only to enable comparisons to be made later in this report. It does not indicate recognition of the term “freight lift”
by CEN.
2.2 Hydraulic terminology
2.2.1 Difference
There are some notable differences in the standards respecting hydraulic lift terminology as shown in the
Table 1, Column A and B.
2.2.2 Agreed-upon points, re: hydraulic terminology
The differences should be eliminated or minimized through proposed changes to ASME and CSA Standards,
as shown in Table 1, Column D.
If approved by ASME and CSA Committees, the proposed changes would eliminate major differences
between CEN and North American Standards.
Column C gives the description of the equipment that a term (listed in Column A, B, or D) embraces.
In addition to “hydraulic machine”, ASME and CSA propose to introduce the term “hydraulic driving machines”
hydraulic driving machines”. The terms are needed to differentiate between “electric” and “hydraulic” driving
machines all covered in one ASME and CSA Standard. This is not necessarily applicable to CEN, as the
electric and hydraulic lifts are covered by two separate standards.
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2.2.3 Terminology in this report
In this report, the CEN terminology will be used, with the ASME and CSA terms in brackets if different.
Table 1 — Hydraulic Terminology
Column A Column B Column C Column D
CEN ASME & CSA Description Agreed upon points:
Current ASME & CSA proposed
changes
Direct acting Direct plunger — Direct acting hydraulic
a
elevator
hydraulic elevator
lift
Indirect acting Roped hydraulic — No change
Elevator
lift
b
Machine — Pump, motor, valves Hydraulic Machine
c
Jack Driving machine Cylinder and ram Hydraulic jack
Ram Plunger or piston — Plunger (ram) or piston
Base Head/bottom Cylinder end cap No change
(Includes plunger end
cap as well)
Valves:
Non-return Check — No change
Pressure relief Pump relief — No change
Direction Control — No change
Rupture ASME-Safety CSA-Rupture — No change
NOTE ASME and CSA adopted terms:
a
“direct-acting”.
b
“hydraulic machine".
c
“hydraulic jack”.
2.3 Working pressure vs full load pressure
ASME and CSA use working pressure (WP), which is defined as the pressure at the hydraulic driving machine
when lifting the car and its rated load at rated speed, or with class C2 loading, when leveling up with maximum
static load.
CEN defines full load pressure (FLP) as the static pressure exerted at the piping directly connected to the jack,
the car with the rated load being at rest at the highest landing level.
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CEN Annex K, clause K.1.1 recognizes that friction losses as a result of fluid flow are on the order of 15 %;
thus a factor of 1,15 is included in their factor of safety determination.
NOTE CEN reference to “Clause 12, NOTE 1” in this clause and through the 1996 edition of this document has been
replaced with reference to “Annex K, Clause K1.1” in this edition.
Thus, ASME WP = 1,15 x (CEN FLP).
2.4 Other terms
Additional terminology, where there is a difference between the CEN and the ASME and CSA standards, is
shown in Table 2:
NOTE Since ASME and CSA are now harmonized they will be shown through this edition in a column under title
“ASME and CSA” or “ASME/CSA”.
Table 2 — Terminology
CEN ASME and CSA
Docking operation Truck zone operation
Electric safety device Electrical protective device
Fixings Fastenings
Landing door Hoistway door
Mains Main power supply
Reeving ratio Roping ratio
Instantaneous safety gear Type A safeties (instantaneous safeties)
Progressive safety gear Type B safeties (progressive safeties)
Pulley Sheave
Safety gear Safeties
Well Hoistway
2.5 Abbreviations
The following abbreviations are used in this report:
FOS = Factor of safety or safety factor.
YP = Yield point.
WP = Working pressure.
UTS = Ultimate tensile strength.
FLP = Full load pressure.
NOTE See also list of abbreviations in item 4.1.2.
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3 Basis for lift safety standards development (basic assumptions)
3.1 Historical background
3.1.1 All lift safety standards assume certain things as being true, without proving them as such, and
stipulate safety rules that are based on these assumptions.
3.1.2 No standard, however, clearly spells out the assumptions used. The CEN committee analyzed its
standard and summarized in the document CEN/TC10/WG1 N99 (see Annex C) the assumptions that, in the
opinion of the committee, were used in the CEN standard.
3.1.3 The CEN assumptions were compared with assumptions implicitly built into other safety standards. It
has been indicated that:
a) some assumptions apparently used in the CEN standard were not listed in the document referred to in
CEN/TC10/WG1 N99;
b) some assumptions used in other standards differ from those in CEN/TC10/WG1 N99.
3.1.4 Using CEN/TC10/WG1 N99 as a model, the following list of assumptions (see 3.3 through 3.9 in this
report) has been developed, which could be used as a basis for future work on safety standards.
The CEN assumptions 5 (related to car speed) and 7 (related to restrictors) as listed in Annex C have not
been considered for adoption in this report, since they are deemed to be design parameters.
Further, CEN assumption 2 is adopted in this report as assumption 1 and CEN assumption 6 as assumption
3(c) in order to be consistent with Part 1 of this report.
In summary, CEN assumptions 1, 3, 4, 8, 9, and 10 correspond to assumptions 1, 2, 3, 4, 5, and 6 in this
report. Assumption 7 is not covered in the CEN document.
3.2 General
3.2.1 Listed in 3.3 through 3.9 (except as noted) are those things specific to lifts that are assumed as true,
although not yet proven or demonstrated as such, including:
a) functioning and reliability of lift components;
b) human behaviour and endurance; and
c) acceptable level of safety and safety margins.
3.2.2 Where the probability of an occurrence is considered highly unlikely, it is considered as not happening.
3.2.3 Where an occurrence proves that an assumption is false, it does not necessarily prove that all other
assumptions are false.
3.2.4 The assumptions should be subject to periodic review by standards writing organizations to ensure
their continuing validity – considering accident statistics, as well as such things as changes in technologies,
public expectations (e.g. product liability), and human behaviour.
3.3 Assumption 1 — safe operation assured to 125 % of rated load
Safe operation of lifts is assured for loads ranging from 0 to 100 % of the rated load. In addition, in the case of
passenger lifts (see 2.1.2), safe operation is also assured for an overload of 25 %; however, it is not
necessary to be able to raise this overload nor to achieve normal operation (rated load performance).
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3.3.1 Rationale for Assumption 1
3.3.1.1 All safety standards limit the car area in relation to its rated capacity (load and/or number of
persons) in order to minimize the probability of inadvertent overloading. However, it is recognized that the
possibility of an overloading of up to 25 % still exists on passenger lifts. To eliminate any hazard for
passengers, safe operation must be assured, but not necessarily normal operation.
3.3.1.2 In the case of freight lifts, no overloading is anticipated. It is assumed that designated attendants
and freight handlers will adhere to instructions posted in cars and will not overload them.
3.3.2 Assumption 1 as applied in current standards
3.3.2.1 Currently CEN does not specifically require a 25 % overload safety margin; however, the design
requirements provide for that level of safety.
ASME and CSA requirements 3.16 and 2.16.8 specifically require that safety be assured on passenger lifts in
the case of 25 % overload.
3.3.2.2 With exceptions given in 3.3.2.5, the ratio of the rated load to the car platform area for passenger
lifts is equal (± 5 %) in all standards for the range of 320 to 4 000 kg, and in that respect, universality of the
assumption #1 is achieved.
However, the assumed average weight of a passenger differs: 75 kg (CEN) and 72,5 kg (ASME and CSA).
3.3.2.3 Furthermore, the rated load to car platform area ratio is different for freight lifts.
2
CEN (non-commercial vehicle with instructed users) 200 kg/m
2
ASME/CSA (general freight Class A) 244/240 kg/m
2
(motor vehicle Class B) 146/145 kg/m
2
(industrial truck Class C) 244/240 kg/m
3.3.2.4 The CEN standard contains two tables showing the ratio between the rated load and the
maximum available car area (for passenger lifts), see Table 3.
The CEN Table “1.1” corresponding to the requirements for electric lifts is based on the rationale explained in
3.3.1.1 and was taken into consideration when formulating the statement in 3.3.2.2.
3.3.2.5 The CEN Table “1.1 A”, acceptable for Goods passengers lifts, is based on the rationale that
where there is a low probability of the car being overloaded with persons, the available area of a hydraulic lift
may be increased up to therein specified maximum, provided that additional safety measures are taken to
ensure the safe interruption in the lift operation. Such measures include:
a) a pressure switch to prevent a start for a normal journey when the pressure exceeds the full load
pressure by more than 20 %;
b) the design of the car, car sling, car-ram connection, suspension means, car safety gear, rupture valve,
clamping or pawl device, guide rails, and buffers must be based on a load resulting from CEN Table “1.1”;
c) the design pressure of the jack and the piping shall not be exceeded by more than 1,4.
Starting point for CEN Table “1.1A” was the comparison of safety factors of driving systems on electric traction
lifts versus hydraulic lifts. On hydraulic lifts the safety factor for the car suspension means and supporting
structure is at least 3 times higher than that of the traction driving systems, when friction between the
suspension ropes and the grooves of the drive sheave is taken into account. Consequently, the safety risk of
unintended car movement downwards due to the overloading on hydraulic lifts is significantly lower than on
electric traction lifts.
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Furthermore, assuming that the car weight is equal to the rated load, in that case an overload of x % on the
electric traction lift would correspond to only x/2 % overload for the hydraulic system.
NOTE This is true for machine power only; not for e.g. safety gear operation, guide rails dimensioning, etc.
2
For car areas up to 5 m , the required rated load in CEN Table “1.1 A” for a hydraulic lift may be 1,6 times less
than the rated load according to CEN Table 1.1.
NOTE 1.6 is an ISO-standard number R5. This is important in view of the rated loads according to ISO 4190-1 1999,
2
Lift (US: Elevator) installation — art 1: Class I, II, III and VI lifts, e.g. a Goods passengers lift with 5 m available car area
requires 2 500 kg rated load in the case of an electric lift, and 1 600 kg in the case of a hydraulic lift. For car areas bigger
2
than 5 m there is no mathematical background.
See Table 3 for an abbreviated comparison of the CEN Tables.
Table 3 — CEN Tables
Rated Load Maximum Car Area Increase in Car Area
"1.1 A" over "1.1"
CEN Table 1.1 CEN Table 1.1 A
for Goods passengers lifts
2 2
kg m m %
400 1,17 1,68 44
800 2,00 2,96 48
1 200 2,80 4,08 46
1 600 3,56 5,04 42
over 1 600, add N/A 0,40/100 kg N/A
2 000 4,20 6,64 58
2 500 5,00 8,84 73
over 2 500, add 0,16/100 kg 0,4/100 kg 250
3.3.2.6 Lift components that are normally designed to withstand, without permanent damage, overloads
greater than 25 % (such as ropes, guides, sheaves, buffers, disconnect switches) are not considered in this
comparison.
NOTE 3.3.2.6 CEN Assumption 2 (see Annex C) is not a new assumption, but rather one of the methods as to how
Assumption 1 is applied in the CEN standard.
3.4 Assumption 2 - failure of electric safety devices
The possibility of a failure of an electric safety device complying with the requirement(s) of a lift safety
standard is not taken into consideration.
Since national safety rules for lifts may be based on different assumptions (some are listed below),
universality of Assumption 2 may be questioned.
3.4.1 Rationale for Assumption 2
Reliability and safety performance of lift components designated as electric safety devices is assured if
designed in accordance with rules contained in a given lift safety standard. However, the design rules may be
based on different assumptions.
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3.4.2 Assumption 2 as applied in current standards
Most methods of assuring performance reliability of electric safety devices are similar in present standards.
There are, however, differences and inconsistencies, as detailed in section 11.
Section 11.1.3 deals in particular with discrepancies in assumptions implied in requirements for design of
electric safety devices.
3.5 Assumption 3 - failure of mechanical devices
a) With the exception of items listed below, a mechanical device built and maintained according to good
practice and the requirements of a standard comprising safety rules for lifts is assumed not to deteriorate
to the point of creating hazards before the failure is detected.
NOTE National practices and safety rules may be different, such as safety factors. See sections 4.1.3 and 4.2.1 of
this report;
b) the possibility of the following mechanical failures shall be taken into consideration:
1) rupture of car suspension means;
2) rupture and slackening of any connecting means such as safety related auxiliary ropes, chains and
belts where the safety of normal lift operation or the operation of a safety related standby component
is dependent on such connections;
NOTE Since 2000, overspeed valve is required by ASME and CSA when flexible hoses are used and
when elevator is located in seismic risk zones 2 or greater;
3) small leakage in the hydraulic system (jack included);
c) the possibility of a car or counterweight striking a buffer at a speed higher than the buffer's rating is not
taken into consideration;
d) the possibility of a simultaneous failure of a mechanical device listed above and another mechanical
device provided to ensure safe operation of a lift, should the first failure occur, is not taken into
consideration.
NOTE 1 The Working Group could not agree upon adopting the CEN Assumption 4.3 (see Annex C) requiring that “the
possibility of rupture in the hydraulic system (jack excluded) shall be taken into consideration”;
NOTE 2 Presently, this assumption is implemented only in CEN by requiring a rupture valve or similar devices, while
CSA assumes the rupture of flexible hoses only and in that case only, the rupture valve is required. In ASME, the
overspeed valve (safety valve) is only required in seismic risk zones 2 or greater.
NOTE 3 The CEN
...
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