SIST EN 12385-6:2004
(Main)Steel wire ropes - Safety - Part 6: Stranded ropes for mine shafts
Steel wire ropes - Safety - Part 6: Stranded ropes for mine shafts
This European Standard specifies the additional materials, manufacturing and testing requirements to those given in Part 1 for stranded ropes (with round and/or shaped strands) and flat ropes for use as hoist ropes, stage ropes and balance ropes in mine-shafts.
It shall be used in conjunction with Parts 1 and 2 of this standard.
NOTE 1 For the purposes of this standard, stage ropes are considered to be hoist ropes.
NOTE 2 This standard may also be used for ropes in other mining applications, e.g. surface mining.
The additional hazards covered by this European Standard are identified in clause 4.
Drahtseile aus Stahldraht - Sicherheit - Teil 6: Litzenseile für Schachtförderanlagen des Bergbaus
Diese Europäische Norm legt die speziellen Anforderungen an Material, Herstellung und Prüfung für Litzenseile (mit Rund- und/oder Formlitzen) sowie Flachseile als Förderseile, Bühnenseile und Unterseile für Schachtförderanlagen des Bergbaus fest.
Sie ist in Verbindung mit EN 12385-1 und EN 12385-2 anzuwenden.
ANMERKUNG Diese Europäische Norm kann auch für Seile anderer Bergwerksanlagen, wie z. B. im Tagebau, angewendet werden.
Die zusätzlichen von diesem Teil der EN 12385 abgedeckten Gefährdungen sind im Abschnitt 4 aufgeführt.
Dieser Teil der EN 12385 gilt für Seile für Neuanlagen und für Seile, die nach dem Erscheinen dieser Norm hergestellt wurden. Sie kann auch auf Ersatzseile für bereits bestehende Anlagen angewendet werden.
Câbles en acier - Sécurité - Partie 6: Câbles d'extraction a torons pour puits de mines
La présente Norme européenne spécifie des prescriptions complémentaires de celles de la partie 1 concernant les matériaux et les prescriptions de fabrication et d'essai des câbles a torons (ronds et/ou formés) et des câbles plats utilisés comme câbles d'extraction, câbles de fonçage et câbles d'équilibre dans les puits de mines.
La présente partie doit etre utilisée conjointement aux parties 1 et 2 de la présente norme.
NOTE 1 Pour les besoins de la présente norme, les câbles de fonçage sont considérés comme des câbles d'extraction.
NOTE 2 La présente norme peut etre également utilisée pour des câbles dans d'autres applications minieres telles que l'exploitation a ciel ouvert.
Les phénomenes dangereux couverts par la présente norme sont identifiés a l'article 4.
Jeklene žične vrvi - Varnost - 6. del: Pramenaste vrvi za rudniške jaške
General Information
Standards Content (Sample)
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Drahtseile aus Stahldraht - Sicherheit - Teil 6: Litzenseile für Schachtförderanlagen des BergbausCâbles en acier - Sécurité - Partie 6: Câbles d'extraction a torons pour puits de minesSteel wire ropes - Safety - Part 6: Stranded ropes for mine shafts77.140.65Jeklene žice, jeklene vrvi in verigeSteel wire, wire ropes and link chainsICS:Ta slovenski standard je istoveten z:EN 12385-6:2004SIST EN 12385-6:2004en01-september-2004SIST EN 12385-6:2004SLOVENSKI
STANDARD
SIST EN 12385-6:2004
EUROPEAN STANDARDNORME EUROPÉENNEEUROPÄISCHE NORMEN 12385-6February 2004ICS 77.140; 77.140.65English versionSteel wire ropes - Safety - Part 6: Stranded ropes for mineshaftsCâbles en acier - Sécurité - Partie 6: Câbles d'extraction àtorons pour puits de minesDrahtseile aus Stahldraht - Sicherheit - Teil 6: Litzenseilefür Schachtförderanlagen des BergbausThis European Standard was approved by CEN on 3 November 2003.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the Central Secretariat or to any CEN member.This European Standard exists in three official versions (English, French, German). A version in any other language made by translationunder the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the officialversions.CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia,Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMITÉ EUROPÉEN DE NORMALISATIONEUROPÄISCHES KOMITEE FÜR NORMUNGManagement Centre: rue de Stassart, 36
B-1050 Brussels© 2004 CENAll rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 12385-6:2004: ESIST EN 12385-6:2004
Contents Page Foreword.4 Introduction.5 1 Scope.6 2 Normative references.6 3 Terms and definitions.6 4 List of hazards.7 5 Safety requirements and/or measures.7 5.1 General.7 5.2 Materials.7 5.2.1 Wire.7 5.2.2 Core.9 5.2.3 Lubricants and impregnating compounds.9 5.3 Rope manufacture.9 5.3.1 Wire joints.9 5.3.2 Wire finish.9 5.3.3 Lubrication.10 5.3.4 Construction.10 5.3.5 Rope grade.10 5.3.6 Stitching of flat ropes.10 5.3.7 Ropes for multi-rope friction hoists.10 5.4 Physical dimensions.10 5.4.1 Diameter.10 5.4.2 Tolerances.10 5.4.3 Permissible differences between diameter measurements.11 5.5 Breaking force.11 5.6 Rope length mass.12 5.7 Designation and classification.12 6 Verification of the safety requirements and/or measures.12 6.1 General.12 6.2 Lubricants.12 6.3 Lubrication.12 6.4 Construction.12 6.5 Test on rope for breaking force.13 6.5.1 Measured breaking force Fm (method 1).13 6.5.2 Measured aggregate breaking force, Fe.m (method 2).13 6.6 Measurement of rope length mass.13 7 Information for use.14 Annex A (normative)
Factors for stranded round ropes.15 Annex B (normative)
Calculation of breaking forces and nominal rope length masses for the more common rope classes and constructions of stranded round ropes.17 B.1 General.17 B.2 Minimum breaking force Fmin.18 B.3 Minimum aggregate breaking force Fe.min.18 B.4 Measured aggregate breaking force Fe.m.18 B.5 Calculated measured aggregate breaking force Fe.m.c.18 B.6 Calculated measured breaking force Fm.c.18 B.7 Nominal rope length mass M.18 SIST EN 12385-6:2004
EN 12385-6:2004 (E) 3 Annex C (normative)
Tables of breaking forces and nominal rope length masses for the more common rope classes of flat ropes.19 Annex D (informative)
Factors for the calculation of the approximate outer wire diameters for the more common rope constructions of stranded round ropes.22 Annex E (informative)
Information which should be provided with an enquiry or order.24 E.1 Details of rope.24 E.2 Details of installation.24 E.2.1 Particulars of the shaft.24 E.2.2 Particulars of friction hoist driving sheave.24
SIST EN 12385-6:2004
EN 12385-6:2004 (E) 4 Foreword This document EN 12385-6:2004 has been prepared by Technical Committee CEN/TC 168 “Chains, ropes, slings, webbing and accessories - Safety”, the secretariat of which is held by BSI. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by August 2004, and conflicting national standards shall be withdrawn at the latest by August 2004. The other Parts of this European Standard are: Part 1: General requirements Part 2: Definitions, designation and classification Part 3: Information for use and maintenance Part 4: Stranded ropes for general lifting applications Part 5: Stranded ropes for lifts Part 7: Locked coil ropes for mine shafts Part 8: Stranded hauling and carrying-hauling ropes for cableway installations designed to carry persons Part 9: Locked coil carrying ropes for cableway installations designed to carry persons Part 10: Spiral ropes for general structural applications
Part 1 provides the general requirements for Parts 4 to 10.
Annexes A, B and C are normative. Annexes D and E are informative. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia,
Spain, Sweden, Switzerland and the United Kingdom. SIST EN 12385-6:2004
EN 12385-6:2004 (E) 5 Introduction During the preparation of this standard, it was assumed that negotiations would take place between the purchaser and the manufacturer concerning the intended purpose of the rope. Customers, purchasers and users should recognize that ropes for mine shafts are, more often than not, specially designed by the rope manufacturer to meet particular hoisting machinery conditions, and particular attention should be given to the selection of the correct dimension(s) of rope and associated tolerance. Although tables with factors for the calculation of breaking forces, nominal rope length masses and outer wire diameters for a number of the more common classes of ropes and tables with physical properties of flat ropes are provided, this part of the standard is not limited to those given, providing all the other requirements are met. SIST EN 12385-6:2004
EN 12385-6:2004 (E) 6 1 Scope This European Standard specifies the special material, manufacturing and testing requirements for stranded ropes (with round and/or shaped strands) and flat ropes for use as hoist ropes, stage ropes and balance ropes in mine shafts. It is used in conjunction with EN 12385-1 and EN 12385-2. NOTE
This European Standard can also be used for ropes in other mining applications, e.g. surface mining. The additional hazards covered by this part of EN 12385 are listed in clause 4. This part of EN 13285 is applicable to ropes for new installations and ropes that have been manufactured after the publication of this standard. It may also be applied to spare ropes for existing installations 2 Normative references This European Standard incorporates by dated or undated reference, provisions from other publications. These normative references are cited at the appropriate places in the text and the publications are listed hereafter. For dated references, subsequent amendments to or revisions of any of these publications apply to this European Standard only when incorporated in it by amendment or revision. For undated references the latest edition of the publication referred to applies (including amendments). EN 10264-2, Steel wire and wire products – Steel wire for ropes – Part 2: Cold drawn non alloy steel wire for ropes for general applications. EN 10264-3, Steel wire and wire products – Steel wire for ropes – Part 3: Round and shaped non alloyed steel wire for high duty applications. EN 12385-1:2002, Steel wire ropes – Safety – Part 1: General requirements. EN 12385-2:2002, Steel wire ropes – Safety – Part 2: Definitions, designation and classification. DIN 21258, Preservative compounds for Koepe friction drive winding ropes in mining – Safety requirements and testing. EN ISO 9001, Quality management systems - Requirements (ISO 9001:2000). ISO 3155, Stranded wire ropes for mine hoisting - Fibre components - Characteristics and tests. ISO 3156, Stranded wire ropes for mine hoisting - Impregnation compounds, lubricants and service dressing - Characteristics and tests. 3 Terms and definitions For the purpose of this European Standard, the terms and definitions in EN 12385-2 apply together with the following: 3.1 calculated rope diameter dc theoretical diameter of a stranded rope where all outer strands just touch each other
3.2 built-up centre centre of a strand comprising a number of small wires manufactured in a separate operation instead of a large disproportional centre wire of a parallel or compound lay construction
SIST EN 12385-6:2004
EN 12385-6:2004 (E) 7 4 List of hazards In addition to the hazards listed in clause 4 of EN 12385-1:2002, where applicable, the hazard associated with the uncontrolled relative movements between the rope and the driving sheave shall be taken into account (see 5.2.2, 5.2.3 and 5.3.3 with regard to the associated requirements). 5 Safety requirements and/or measures 5.1 General In addition to the requirements given in 5.2 to 5.7, the requirements shall also conform to those given in
EN 12385-1. 5.2 Materials 5.2.1 Wire 5.2.1.1 Before ropemaking Round wires, except those which form a built-up centre shall conform to: a) EN 10264-3 for hoist ropes and stage ropes; and b) EN 10264-2 for balance ropes and the stitching wires of flat hoist ropes. For a given rope grade, the tensile strength grades of the wires of stranded round ropes and flat ropes shall not exceed the limits given in Table 1.
Table 1 — Tensile strength grades of wires in stranded round ropes and flat ropes for a given rope grade Rope grade Tensile strength grade in N/mm²
minimum maximum 1180 1180 1370 1270 1180 1370 1370 1180 1570 1570 1370 1770 1670 1570 1860 1770 1570 1960 1860 1670 1960 1960 1770 1960 outer wires; 2160 inner wires
For shaped wires as centre wires, the tensile strength grade shall be less than or equal to 900 N/mm², with a tolerance not greater than that of the round wires of the same nominal metallic cross-section. The tensile strength grades of round and shaped wires used to form built-up centres shall be at least 300 N/mm2. For flat ropes, all loadbearing wires shall be of the same tensile strength grade. For outer wires the maximum tensile strength grade shall be 1960 N/mm² for bright and class B zinc-coated wires and 1770 N/mm² for class A zinc-coated wires. For inner wires the maximum tensile strength grade shall be 2160 N/mm² for bright and class B zinc-coated wires and 1770 N/mm² for class A zinc-coated wires. The minimum tensile strength grade of stitching wires for flat hoist ropes shall be 1150 N/mm². SIST EN 12385-6:2004
EN 12385-6:2004 (E) 8 The maximum tensile strength grade of the stitching wires for all flat ropes shall be limited to 75 % of the tensile strength grade of the loadbearing wires. The tensile strength range shall be 300 N/mm². Reverse bend and torsion requirements are not applicable to stitching wires. The minimum diameter of the wires, excluding any filler wires and round wires for built-up centres, shall conform to Table 2. NOTE The approximate outer wire diameters of round-strand round ropes can be calculated with the formulae and factors given in Annex D. Table 2 — Minimum wire diameters, excluding round wires for built-up centres and filler wires Dimensions in millimetres Rope type Rope diameter d Minimum wire diameter d ≤ 18 0,5 18 < d ≤ 25 0,8 d > 25 1,0
Stranded round ropes Minimum wire diameter for stranded round mine hoist ropes: 0,8 mm Flat ropes - 1,0
5.2.1.2 After ropemaking
Test methods and acceptance criteria for wires taken from the rope shall meet the requirements for stranded ropes in annex B of EN 12385-1:2002 with the addition that at least 90% of all of the wires tested shall be within the specified values. Filler and centre wires shall also be tested. In the case of built-up centres, either the individual wires or the centre as a whole shall be tested only for tensile strength. The tensile strength of wires from strands that have been compacted shall be calculated on the basis of their respective nominal diameters before stranding and compacting. The scope of the sampling depends on whether or not the rope manufacturer operates an independently verified quality management system: a) rope manufacturers operating a quality management system in accordance with EN ISO 9001 certified by an accredited third party certification body shall test the number of specimens given in annex B of EN 12385-1:2002 when the breaking force of the rope is specified as the minimum aggregate breaking force Fe.min . For flat ropes, the wires of one left-hand and one right-hand unit rope shall be tested; b) rope manufacturers NOT operating a quality management system in accordance with EN ISO 9001 certified by an accredited third party certification body shall test all loadbearing wires except those forming the built-up centre for: dimensions, tensile strength, reverse bend and torsion. Built-up centres shall be tested only for tensile strength. A test of the zinc coating shall be carried out on at least 20 % of wires of the same diameter in the same wire layer.
SIST EN 12385-6:2004
EN 12385-6:2004 (E) 9 5.2.2 Core Cores shall be one of the following types: a) fibre; b) fibre, reinforced by non-loadbearing wires; c) independent steel wire rope covered with fibre or solid polymer; d) independent steel wire rope with fibre or solid polymer covered outer strands, or; e) independent steel wire rope with or without fibre or solid polymer inserts. Fibre cores and fibre inserts shall be free of water-soluble aggressive acids and be made of either new hard fibre (sisal or manila) or man-made fibres. They shall meet the requirements of ISO 3155. Fibre cores, inserts and coverings shall be impregnated to resist corrosion and rot.
If the impregnating agent has to be heated for workability purposes, the temperature shall not reach a value that is liable to damage the fibre. The new fibrous material for friction hoist ropes shall have an extractable content, including the batch, of a maximum of 5 % of the mass of the dry fibre before ropemaking. The extractable content of the impregnated or lubricated fibrous material before ropemaking shall have a maximum of 25 % of the mass of the dry fibre. 5.2.3 Lubricants and impregnating compounds
The lubricant and any impregnating compounds for hoist ropes shall conform to ISO 3156. For friction hoist ropes, DIN 21258 also applies. The properties of the friction hoist rope lubricant shall take account of: - the coefficient of friction between the rope and the drive sheave, and; - the chemical compatibility of the lubricant with the respective sheave linings.
5.3 Rope manufacture 5.3.1 Wire joints The minimum distance between planned wire joints for hoist ropes shall be 36 x nominal rope diameter. 5.3.2 Wire finish Within a rope with zinc-coated wires, wires with both class A and class B finishes may be used provided that wires within the same layer are of the same class of finish. This is valid also for the filler and centre wires of round ropes, as well as for the stitching wires of flat ropes. NOTE The purchaser should specify any special wire finish requirements.
SIST EN 12385-6:2004
EN 12385-6:2004 (E) 10 5.3.3 Lubrication Drum hoist ropes shall be lubricated during the stranding and closing processes.
If the outer strand or the outer wire layer of the strands are not lubricated, all the wires shall be zinc coated. NOTE The purchaser should specify any special lubrication requirements. 5.3.4 Construction The rope construction shall be either one of those covered by the respective classes for stranded round and flat ropes as given in clause 5 of EN 12385-2:2002 or another construction as specified by the manufacturer. NOTE 1
Where another construction is specified by the manufacturer, this should be agreed with the purchaser. NOTE 2
Strands can be compacted. 5.3.5 Rope grade The rope grade shall not be less than 1270 or greater than 1960 for ropes with bright and class B zinc-coated wires and not less than 1270 or greater than 1770 for ropes with class A zinc-coated wires. The common rope grades for hoist ropes are 1570, 1670, 1770, 1860 and 1960, for flat balance ropes 1370 and 1570 and for round balance ropes 1180, 1270, 1370, 1570 and 1960. The rope grade shall be used in the calculation of minimum breaking force and minimum aggregate breaking force according to annex B. 5.3.6 Stitching of flat ropes Flat hoist ropes shall be single stitched. Flat balance ropes shall be single stitched, double stitched or riveted. 5.3.7 Ropes for multi-rope friction hoists Apart from the directions of lays, the rope designs shall be the same for all ropes manufactured as a set for a particular installation. 5.4 Physical dimensions 5.4.1 Diameter
In the case of 6- to 8-strand round strand hoist ropes with a fibre core according to 5.2.2 a) or reinforced fibre core according to 5.2.2 b), the nominal rope diameter d shall be equivalent to the calculated rope diameter, dc. 5.4.2 Tolerances When measured in accordance with 6.3.1 of EN 12385-1:2002, the rope diameter shall not vary from the nominal diameter d
by more than the values given in Table 3. When measured in accordance with 6.3.2 of EN 12385-1:200, the width and thickness of flat ropes shall not vary from the nominal width and thickness by more than the values given in Table 3.
SIST EN 12385-6:2004
EN 12385-6:2004 (E) 11
Table 3 — Tolerances Rope type Rope dimension Tolerance % 6- to 8-strand round strand hoist rope with FC according to 5.2.2 a) or 5.2.2 b) d = dc + 2 to + 5 6- or 8-strand round strand hoist rope with IWRC d 0 to + 5 6-strand triangular strand hoist rope with FC d + 2 to + 5 Rotation-resistant round strand hoist rope d 0 to + 5 Rotation-resistant oval strand hoist rope d 0 to + 7 Round balance rope d 0 to + 5 Width (including stitching) - 5 to + 5 Flat hoist rope Thickness - 10 to +10 Width (including stitching/rivets) - 10 to +10 Flat balance rope Thickness -10 to +10 NOTE 1 Purchasers or users should take the above tolerances into account, particularly when ordering or selecting a replacement hoist rope in order to assure themselves that the rope is compatible with the equipment (hoist and end attachments) with which it is intended to be used. NOTE 2 A reduced tolerance may be necessary for drum hoist ropes.
5.4.3 Permissible differences between diameter measurements The difference between any two of the four measurements referred to in 6.3.1 of EN 12385-1 shall not exceed 4 % of the nominal rope diameter. The difference between the average of the two measurements taken at each of the two positions referred to in 6.3.1 of EN 12385-1, shall not exceed 3% of the nominal rope diameter.
5.5 Breaking force The breaking force shall be specified as either the minimum aggregate breaking force Fe.min
or, with the exception of flat ropes, the minimum breaking force Fmin .
The minimum breaking force values of the more common rope classes, with the exception of the flat ropes, shall be calculated using the formulae of Annex B on the basis of the factors given in Annex A. When calculating the aggregate breaking force Fe.c.min of ropes with fibre cores reinforced by non-loadbearing wires, these wires are not included in the calculation.
In this case, note 2
of this subclause does not apply. The minimum aggregate breaking forces for the more common classes of flat hoist ropes and flat balance ropes are given in the tables of Annex C. NOTE 1 Depending on the actual rope design, higher values of breaking force than those calculated in accordance with annex B or given in the Tables C.1 and C.2 can be specified. NOTE 2 Certain elements of a rope can be disregarded when calculating the aggregate breaking force. The value in this case is referred to as the reduced aggregate breaking force Fe.red.min. The manufacturer shall carry out a breaking force test in accordance with 6.5 on a sample of rope from each production length. SIST EN 12385-6:2004
EN 12385-6:2004 (E) 12 When tested in accordance with 6.5, the measured breaking force shall be equal to or greater than the specified breaking force value. NOTE 3 When regulations require either the measured aggregate breaking force or the measured breaking force as verification of the safety requirements, the particular verification requirements should be specified by the purchaser in the enquiry or order. 5.6 Rope length mass The nominal rope length mass M of the more common rope classes, with the exception of flat ropes and round balance ropes, shall be calculated with the formulae in annex B and the factors in annex A. For round balance ropes and those rope classes not contained in annex A, the manufacturer shall specify the nominal rope length mass. NOTE The rope length mass factors in Table A.1 for round balance rope are for information only. For flat ropes, the nominal rope length mass values given in Tables C.1 and C.2 shall be used. The manufacturer shall carry out a test for rope length mass as described in 6.6 When measured as described in 6.6, the actual rope length mass shall be subject to a tolerance of - 2 % to + 5 % for stranded round ropes and - 5 % to + 5 % for flat ropes. 5.7 Designation and classification Rope designation and classification shall conform to EN 12385-2. 6 Verification of the safety requirements and/or measures 6.1 General The safety requirements and/or measures shall be verified in accordance with clause 6 of EN 12385-1:2002 and the other characteristics in accordance with 6.2 to 6.6 below. 6.2 Lubricants A visual check of the test documents supplied with the lubricants shall be carried out to verify that the lubricants meet the relevant requirements. 6.3 Lubrication A visual check shall be carried out to verify that the lubrication requirements have been met. 6.4 Construction A visual check shall be carried out to verify that the construction requirements have been met. SIST EN 12385-6:2004
EN 12385-6:2004 (E) 13 6.5 Test on rope for breaking force 6.5.1 Measured breaking force Fm (method 1) If the breaking force of the rope is specified as minimum breaking force Fmin
it shall be verified by the measured breaking force Fm. If the manufacturer is NOT operating an independently verified quality management system in accordance with EN ISO 9001, the method of test for determination of the measured breaking force Fm shall be in accordance with 6.4.1 of EN 12385-1:2002. If the manufacturer is operating an independently verified quality management system in accordance with EN ISO 9001, the method of test for determination of the measured breaking force shall be either a) in accordance with 6.4.1 of EN 12385-1:2002, or b) in accordance with 6.4.3 (method 3) of EN 12385-1:2002. 6.5.2 Measured aggregate breaking force, Fe.m (method 2) If the breaking force of the rope is specified as the minimum aggregate breaking force Fe.min, it shall be verified by the measured aggregate breaking force, Fe.m. If wires of fibre cores reinforced with wires are tested, these test results shall not be used when determining the measured aggregate breaking force of the rope If the manufacturer is NOT operating a quality management system in accordance with EN ISO 9001 certifi
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.