DRAFT IN WIDE CIRCULATION Document Despatch Advice

Size: px

Start display at page:

Download "DRAFT IN WIDE CIRCULATION Document Despatch Advice"

Marilynn Tucker
6 years ago
Views:

1 DRAFT IN WIDE CIRCULATION Document Despatch Advice TECHNICAL COMMITTEE INDUSTRIAL GASES SECTIONAL COMMITTEE, CHD ADDRESSED TO: 1. All Interested Members of Chemical Division Council CHDC. 1. All Members of Industrial Gases Sectional Committee, CHD All Members of its Subcommittees and alert panel. 3. All Others interested Dear Sir/Madam, Please find enclosed the following draft document: DOC.NO TITLE CHD 6/DOC IS 309 Oxygen, compressed gas and liquid Specification (fifth revision) The document is also hosted on BIS website Kindly examine the above document and few comments already received from stakeholders as enclosed. Please forward your views stating any difficulties which you are likely to experience in your business or profession, if the above draft is finally adopted as National Standard. Last Date for Comment is 19 October Comments, if any, may please be made in the format as annexed and mailed to the undersigned at the above address. In case no comments are received, we would presume your approval of the document. However, in case we receive any comments on the document, the same shall be put up to the Sectional Committee for necessary action. Thanking you, Ref. Date CHD 6/DOC (10520) 19 July 2016 Yours faithfully, Encl.: As above (U. K. Das) Scientist E & Head (CHD)

2 य पक पर च लन स द स दभभ ददन क स एच ड 6/ ज ल ई 2016 तकन क सम तत:- औ य चगक ग स व षय सम तत, स एच ड 06 र वषत 1 स यतनक व भ ग पर षद (स एच ड स ) क सदस य 2 रस धन सम तत, स एच ड 06 ए इसक सभ उपसम ततय क स स त सदस य 3 चच खन ल सभ तनक य ह दय/ ह दय, आपक अ ल कन ह त तन नमलखखत भ त य नक क स द स लग न ह : स द स ख य स एच ड 6/10520 व षय ऑ ससजन, स प ड त ग स औ र व म ट (प च प न षण) क पय इन स द क अ ल कन क अपन स ततय यह बत त ह ए भ ज कक यदद अ तत: यह नक स द र य नक क प रक म त ह ज ए त इन प अ ल क न आपक य स य अथ क ब क य कद न इय आ सकत ह स ततय भ जन क अ तत ततचथ: 19 असट ब 2016 स ततय क पय स लग न र प अध -हस त ष क भ ज ध य द, भ द य स ल न: उप सतमलखखत य क द स ञ तनक 'ई' ए र ख (स एच ड )

3 DRAFT FOR COMMENTS ONLY Doc: CHD 06( ) 19 July 2016 BUREAU OF INDIAN STANDARDS Draft Indian Standard OXYGEN, COMPRESSED GAS AND LIQUID SPECIFICATION (Fifth Revision of IS 309) (Not to be reproduced without the permission of BIS or used as STANDARD) Last date for receipt of comments is ICS no FOREWORD (Formal clauses will be added later) This standard was originally published in 1956 and then subsequently revised in 1965, 1974, 1992 and 2005.In third revision a new method of test for determination of moisture has been incorporated. The packing of compressed oxygen gas in cylinders and the marking of the cylinders made to conform to the provision of the Gas cylinder rules, 2004 of the Government of India, with such modifications as may be issued time to time by the chief controller of Explosives. In fourth revision, standard method of test for determination of carbon monoxide, carbon dioxide has been incorporated with a view to harmonize it with corresponding British Standard BS 4364:1993 Specification for industrial oxygen. In this standard, two major changes have been made. 1) Incorporation of Liquid oxygen as there was no such standards available as on date and with a view to align it with provisions in product variety of liquid Argon standard, viz. Argon, compressed and liquid specification IS 5760:1998 as decided in CHD 6 meeting. 2) Considerable assistance has been taken from BS 4364:1993 Specification for Industrial Oxygen for prescription of test method based on magneto-dynamic analyzer for the determination of Oxygen content, which is a more acceptable and practiced test method. 3) Introduction of Pure Grade / Liquid Oxygen specification along with the commercial grade already specified in earlier version. At present, there is no ISO standard on the subject. As stringent limits of impurities have been prescribed for Pure Grade / Liquid Oxygen (Grade 1), the analysis of this grade of oxygen demands the employment of sophisticated modern instruments having high degree of sensitivity and precision. In view of this, the conventional forms of glass test sets and apparatus have not been prescribed for Grade 1 Oxygen. The equipment and the instruments prescribed for analysis are modern instruments with high degree of reliability. The Grade 2 is the commercial grade, which has not been altered in characteristic requirement from the earlier version where only one grade was there under Compressed Oxygen Gas Specification.

4 Draft Indian Standard OXYGEN, COMPRESSED GAS AND LIQUID - SPECIFICATION (Fifth Revision) 1. SCOPE This standard prescribes requirements and methods of sampling and test for oxygen, compressed gas and liquid. 2. REFERENCES This standards listed below contain provisions, which through reference in this text constitute provisions of this Indian Standard. At the time of publication, the editions indicated were valid. All standards are subject to revision and parties to agreements based on this Indian Standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below: IS No : 2015/ ISO 24153:2009 Title Random sampling and randomization procedures (first revision) 7062 : 1973 Glossary of terms used in gas industry 3. TERMINOLOGY For the purpose of this standard, the definitions given in IS 7062 shall apply. 4. GRADES There shall be two grades of oxygen, namely, Grade 1 Grade 2 Pure grade oxygen for use in laser cutting as an assist gas for automotive, textile machinery industries where the quality of surface after cutting are enhanced significantly compared to usage of normal commercial grade oxygen. Liquid oxygen specification has been aligned with this grade and all the measurements for the liquid to be done in gas phase only. Commercial grade oxygen for use in welding industry and for other metallurgical operations. 5. REQUIREMENTS 5.1 The material shall be compressed gas or liquid for vaporization. 5.2 The material shall comply with the requirements prescribed in Table 1 when tested in accordance with the methods prescribed in Annex A. Reference to the relevant clauses of Annex A is given in column 5 of Table PACKING AND MARKING 6.1 The gas shall be supplied compressed in cylinders or liquid oxygen tanks. The design of cylinders or liquid oxygen tanks, the maximum pressure of oxygen in them, and packing, marking, painting, labeling and transport of cylinders tanks shall be in conformity with the Static and Mobile Pressure Vessels (Unfired) (SMPV (U)) Rules 1981 and Gas Cylinders Rules, 2004 of the

5 S. No. 1 Government of India, with modifications as may be ordered from time to time by Petroleum and Explosive Safety Organization (PESO) or any other authority duly constituted by the government of India. Table 1 Requirement for Oxygen, Compressed and Liquid Characteristic 2 (Clauses 5.2 and B-3) Requirement Grade 1 Grade 2 Method of Test (Ref to Cl No. in Annex A) i) Oxygen, % (v/v), Min A-1 ii) Nitrogen, ppm, Max A-3 iii) Water vapour, ppm, Max A-4 iv) Carbon dioxide, ppm, Max A-2, A-5 v) Carbon monoxide, ppm, Max A-2, A-6 vi) Hydrocarbons, ppm, Max A-2, A-7 Note: Oxygen gas produced by air separation shall not normally contain any carbon monoxide, carbon dioxide and hydrocarbon. So for the presence of these impurities in oxygen, compressed and liquid produced by air separation process, tests shall be carried out only on agreement between the buyer and the seller. For oxygen (both compressed and liquid) produced by other methods the determination of the mentioned impurities, viz. carbon monoxide, carbon dioxide and hydrocarbon shall be carried out along with other tests mentioned in Table SAMPLING The method of drawing representative samples from a lot, number of tests to be performed and the criteria for conformity of the material to the requirements of this specification shall be as prescribed in Annex B.

6 ANNEX A (Clause 5.2) METHODS OF TEST FOR ANALYSIS OF OXYGEN, COMPRESSED AND LIQUID A. GENERAL Only instrumental methods of test have been prescribed for analysis of oxygen, compressed and liquid. Instrumental Methods ascribed in this standard are listed in Table 1. Instrumentation Involved Component Instrument Section Oxygen Magneto dynamic analyser A-1 S.No Impurity Instrument Section 1. Carbon monoxide Gas chromatograph / IR analyser 2. Carbon dioxide Gas chromatograph / IR analyser 3. Hydro carbon Gas chromatograph / IR analyser A-2 / A-5 A-2 / A-6 A-2 / A-7 4. Nitrogen Spectra analyser A-3 5. Water vapour Electrolytic Hygrometer / Frost or Dew Point Hygrometer / Capacitance Hygrometer A-4 A-1 DETERMINATION OF OXYGEN A-1.1 Method for determination of oxygen content. A-1.2 Principle The method uses the principle of paramagnetic susceptibility, a physical property which is considerably greater in oxygen than in other common gases. Oxygen molecules are more strongly attracted by a magnetic field than are molecules of other gases, most of which, being diamagnetic, are repelled by a magnetic field. Magneto dynamic analyzers are based on Faraday s method of determining the magnetic susceptibility of a gas by measuring the force developed by a strong non-uniform magnetic field on a diamagnetic test body suspended in the sample gas. The test bodies of all measuring cells in paramagnetic oxygen analyzers consist of two nitrogen-filled quartz spheres arranged in the form of a dumb-bell, as shown in Figure 1.1. A single turn of platinum wire (the feedback coil) is secured in place around the dumb-bell. A rugged, taut band platinum ribbon suspension attached to the mid-point of the dumb-bell positions the dumb-bell in the strong non-uniform magnetic field existing between

7 the specially shaped pole pieces of the permanent magnetic structure.(ref: Fig 1.2). A typical analyzer configuration (electronic) is shown in Fig.1.3. A Instrument A variety of analytical equipment suppliers provide simple, ready to run portable units for this purpose, which may be powered either by battery or by mains electricity. Figure 1.3 illustrates the configuration of a typical unit designed for this purpose. A Calibration Calibration of these units shall be carried out using a calibration standard that is assured by analysis traceable gravimetrically to national standards and of purity >99.95% (v/v) oxygen and the instrument manufacturer s instruction in this regard, shall be followed.

8 A Procedure After calibrating the instrument, introduce the sample of the product in accordance with the instrument manufacturer s instruction. Record the oxygen content that is displayed by the instrument. A-2 DETERMINATION OF CARBON DIOXIDE, CARBON MONOXIDE AND HYDROCARBONS A-2.1 Gas Chromatographic Method A Principle Chromatography is a process of separation achieved by means of a partition between a stationary phase and a moving phase. A suitable synthetic zeolite and suitable detector are used in chromatography. When the accuracy of analysis is to be achieved at the level of 1 ppm (v/v) [vpm], the results obtained are always relative to the impurities of carrier gas and are not absolute values. Hence, the ultra high purity carrier gas, that is, Grade 1 argon is to be purified further by a suitable rare gas purifier to achieve zero impurity carrier gas. The purifier system consists of titanium granules at 700 C for removal of nitrogen and oxygen, a copper oxide furnace for removal of hydrogen and carbon monoxide, and molecular sieve to remove carbon dioxide and moisture. The construction of the gas chromatograph is the same as that of any gas chromatograph with a gas sampling value and a loop of known volume. The column material is molecular sieve 5 A filled in stainless steel column of 4 m length and 4.6 mm internal diameter. The column is regenerated at 250 C in a stream of argon for about 4h. The detector is the most important part of the whole assembly and is called argon discharge detector. Purified carrier argon gas, which passes through the detector chamber, is subjected to a strong electromagnetic field maintained between two electrodes by a high frequency generator. The resulting luminescence is modified subsequently by any other element passing through the chamber. The high frequency generator is operated on a stabilized voltage. The luminous intensity of the gas discharge tube is measured by means of a photo resistive cell, which is one of the branches of the bridge whose unbalanced voltage is the output signal for recording or integrating. Alternatively these impurities can be measured in a gas chromatograph having Flame Ionization Detector (FID) with methanizer. Column in Gas Chromatograph in this case will be Shin Carbon ST 100/120 mesh, 2 meters, 1.16" OD. The oven temperature and detector temperature is to be kept at 90 C and 200 C respectively. Carrier gas is the same that is grade 1 argon as specified earlier. One typical calibration chromatogram and one typical sample chromatogram is attached in Fig 2 & Fig 3.

11 Gas Chromatograph method for determination of carbon monoxide, carbon dioxide and hydrocarbon: Detector = FID with Methanizer Column = ShinCarbon ST 100/120 mesh, 2 mtrs, 1.16" OD. Oven Temp = 90 C Detector Temp = 200 C. Used Std ( 9 ppm CO, CH 4 & CO 2 Each ) Ret. Time of Peak - Peak Area CO = 1.60 min CH 4 = 2.79 min CO 2 = 5.63 min Testing of Oxygen results, Ret. Time of Peak - CO = 1.59 min Peak Area Nil (No detection) CH 4 = 2.91 min CO 2 = 5.61 min Nil (No detection) As per Calculation CH 4 present in Oxygen = (10x / )ppm = ppm. Chromatograms attached both for calibration and sample run. Report for Sample Tested on 10/03/2015 Typical Calculation for the impurities CO, CO 2 & Hydrocarbon A Procedure Calibrate the instrument against calibration gas of known composition by measuring the peak heights or areas under various peaks of the chromatograph following the instructions of the manufacturer. Carry out the test according to the manufacturer s instructions and compute the concentration of the various impurities by comparing the peaks or the areas under peaks with that of the calibration gas. A-3 DETERMINATION OF NITROGEN A-3.1 General Two methods have been prescribed, namely, gas chromatographic method and spectra analysis method. A Spectra Analysis Method

12 A Principle The spectra analyser determines nitrogen in oxygen in the range of 0 to 100 ppm (v/v). The analyser is based around a pyrex/quartz cell through which the test gas is passed. A high AC voltage is applied to this cell which causes ionization of the gas and consequent emission of light. A particular and proportionate fraction of this light results from the ionization of nitrogen which is present in the sample. The intensity of emission of light is proportional to the nitrogen concentration. The emitted light passes through a chopper and narrow band interference filter. The transmitted light, which is proportional to the nitrogen present in the test gas, is detected by a photo multiplier tube and converted into electrical signal. The signal is pre amplified and measured. The analyser is to be calibrated by a standard gas. A Procedure It shall depend on the type of analyser used. The instrument manufacturer s instructions in this regard shall be followed. A-4 DETERMINATION OF WATER VAPOUR A-4.1 General Four methods have been prescribed. Three methods are instrumental namely, electrolytic hygrometer, frost or dew point hygrometer and capacitance hygrometer. Fourth one is absorption method. For routine analysis any of the methods may be employed. However, in case of any dispute in the determination of water vapour, absorption method shall be used as a referee method. A Electrolytic Hygrometer The method is based on the absorption and electrolysis of the water vapour present in the sample gas. The electrolytic current gives a direct measurement of water vapour present in the gas flowing through the instrument at a steady rate. The exact procedure to be followed shall depend on the type of apparatus to be used. The instrument manufacture s instructions in this regard shall be followed. A Frost or Dew Point Hygrometer A metal surface on the hygrometer is cooled so that dew or frost is formed from the water vapour content of the gas at a particular pressure which may be observed optically in the apparatus. The temperature at which the dew or frost is formed is a measure of water vapour content of the gas. The exact procedure to be followed shall depend upon the type of apparatus to be used. The instrument manufacturer s instructions in this regard shall be followed. A Capacitance Hygrometer The method is based on the change of capacitance of the sensor when a sample gas containing water vapour passes through it. The change in capacitance gives a direct measurement of water vapour present in the gas. The procedure to be followed shall depend upon the type of apparatus to be used. The instrument manufacturer s instructions in this regard shall be followed. A Absorption Method A Apparatus The apparatus consists of the following parts assembled as shown in Fig.4.

13 The apparatus consists of the following parts assembled as shown in Fig.4. A Gas meter accurate to 1 percent A Absorption train Three U-tubes containing Phosphorus pentoxide connected in series to the gas meter. The one near to the gas meter will serve as a guard to prevent moisture from backing into the first two tubes. A Procedure Connect the three tubes in series to the inlet of the gas meter and connect the free end of U-tubes to the gas sample. Allow the gas to flow through the train for a while to saturate the water in the gas meter with the gas as well as replacing the air in the first two U-tubes. Stop the gas flow, close the stopcocks of the U-tubes and weigh the first two U-tubes. Connect again, record the meter reading. Pass the gas through the train at the rate of 10 litres per hour for 4 to 5 h. Close the gas supply and record the meter reading. Remove the first two U-tubes and weigh. A Calculation Convert the volume of gas taken for the test to normal temperature and pressure. From the increase in weight, calculate the volume of water vapour present on the basis that 1g of water is equivalent to litres of water vapour at normal temperature and pressure and express the result as parts per million volume by volume. A-5 DETERMINATION OF CARBON DIOXIDE A-5.1 General Three methods have been prescribed, namely, infra-red analysers, electrochemical method and gas chromatographic method.

14 A Infra-Red Analyser The infra-red analysers are used for determining impurities of hetero-atomic gases. The hetero atomic gases absorb energy at characteristic wavelengths when subjected to infra-red radiation. The procedure to be followed for determining the impurities shall depend on the type of apparatus to be used. The instrument manufacturer s instructions in this regard shall be followed. A Electrochemical Method When a gas containing carbon dioxide passes through a reactive liquid, the electrical conductivity of the liquid changes depending on the carbon dioxide content. The measurement of the change in electrical conductivity gives a direct measurement of the carbon dioxide content. The procedure to be followed shall depend upon the type of apparatus to be used. The instrument manufacturer s instructions in this regard shall be followed. A Gas Chromatographic Method The procedure for carrying out the determination shall be the same as prescribed under A-2. A-6 DETERMINATION OF CARBONMONOXIDE Two methods have been prescribed namely, gas chromatographic method and infra-red analyser method. A Gas Chromatographic Method The procedure for carrying out the determination shall be the same as prescribed under A-2. A Infra-Red Analyser Method The procedure for carrying out the determination shall be the same as prescribed under A A-7 DETERMINATION OF HYDROCARBONS A-7.1 General Three methods have been prescribed, namely, gas chromatographic method, infra-red analyser method and total hydrocarbon method. A Gas Chromatographic Method The procedure for carrying out the determination shall be the same as prescribed under A-2. A Infra-Red Analyser Method The procedure for carrying out the determination shall be the same as prescribed under A A Total Hydrocarbon Analyser Method A Principle The sample containing hydrocarbon impurities is burnt in a jet of hydrogen in the flame ionization detector and the organic component present in the sample gas provides the source of ions. Concentration of ions is proportional to be concentration of organic components. Electrodes having considerable potential difference between them are used to measure the current produced due to ionization and the instrument is calibrated in the terms of concentration of hydrocarbons. Total Hydrocarbon Analysers with flame ionization detectors are commercially available.

15 A Procedure Calibrate the instrument against calibration gas of known concentration of hydrocarbon following the instructions of the manufacturer. Then carry out the test according to the instrument manufacturer s instructions.

16 B-1 SCALE OF SAMPLING ANNEX B (Clause 7) SAMPLING OF COMPRESSED OXYGEN B-1.1 Lot - In any consignment, all cylinders charged at a time from one charging manifold shall constitute a lot. B-1.2 The number of cylinders (n) to be selected from a lot shall depend on the size of the lot (N) and shall be in accordance with col 1 and 2 of Table 2. B The cylinders shall be selected at random and in order to ensure the randomness of selection, a random number table (see IS 4905) shall be used. In case such a table is not available, the following procedure shall be followed. Starting from any cylinder in the lot, count them in one orders as 1,2,3. up to r and so on, where r is the integral part of N/n. Every r th cylinder thus counted shall be withdrawn to give the sample for test. B-2 TEST SAMPLES A sample of gas shall be drawn from each cylinder selected as in B-1.2 and shall be the individual test sample from each cylinder. Table 2 Number of Cylinders to be Selected Lot Size (N) (Clause B-1.2) Number of Cylinders To be Selected (n) (1) (2) Up to to to to and above 25 B-3 NUMBER OF TESTS All the individual test samples in B-2 shall be tested separately for the requirements given in Table 1. B-4 CRITERIA FOR CONFORMITY A lot shall be declared as conforming to the requirements of this specification if all individual samples tested, pass the requirements prescribed in 5.2.

17 FORMAT FOR SENDING COMMENTS TO BIS (Please use A4 size sheet of paper only and type with fields indicated. Comments on each clauses/subclauses/table/fig. Etc. be started on a fresh box. Information in column 4 should include reasons for the comments and suggestions for modified wording of the clauses when the existing text is found not acceptable. Adherence to this format facilitates Secretariat s work). DOC NO...TITLE DATE OF CIRCULATION NAME OF THE COMMENTATOR/ ORGANIZATION. SL NO. CLAUSE/SUB- CLAUSE/PARA/TABLE COMMENTATOR/ ORGANIZATION COMMENTS DECISIONS FIG. NO. ABREVIATION COMMENTED (1) (2) (3) (4) (5)

Gaseous oxygen technical grade Specification

CDC 09 (5010) P3 Rev. TZS 217:1984 FINALIZED TANZANIA STANDARD Gaseous oxygen technical grade Specification TANZANIA BUREAU OF STANDARDS. 2 nd edition TBS 2017 0. FOREWORD 0.1. This Tanzania Draft Standard