1、CEN EN*29090 92 3404589 0028958 2 EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 29090 May 1992 UDC 621.791.5.032:620,165.29 Descriptois: Welding, gas welding, welding equipment, specifications, gas permeability tests English version Gas tightness of equipment for gas welding and allied proces
2、ses (IS0 9090: 1989) Etanchit aux gaz des appareils pour soudage aux gaz et techniques connexes (IS0 9090: 1989) Gasdichtheit von Gerten fr GasschweiBen und verwandte Verfahren (IS0 9090: 1989) This European Standard was approved by CEN on 1992-05-22. GEN membeis are bound to comply with the CENICEN
3、ELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any
4、CEN member. This European Standard exists in three official versions (English, French, Geiman). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the official versions. CEN
5、 members are the national standards bodies of Austria, Belgium, Denmark, Finland, France, Geimany, Greece, IceIand, Ireland, Italy, Luxembourg, Netherlands, Norway, Poitugal, Spain, Sweden, Switzerland and United Kingdom. CEN European Committee for Standardization Comit Europen de Normalisation Euro
6、pisches Komitee fr Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels O 1992 Copyiight reserved to CEN members Ref. No. EN 29090 : 1992 E CEN EN*29090 92 W 3404589 0028959 4 .Page 2 EN 29090 : 1992 Foreword In September 1991, CEN %chnical Board decided to submit the International Stand
7、ard IS0 9090 : 1989 Gas tightness of equipment for gas welding and allied processes to the formal vote procedure. The result was positive and the standard is now adopted as a European Standard. National standards identical to this European Standard shall be published at the latest by 1992-11-30 and
8、conflicting national standards shall be withdrawn at the latest by 1992-11-30. According to the CENKENELEC Common Rules the following countries are bound to implement this European Standard: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands
9、, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. Endorsement notice The text of the International Standard IS0 9090: 1989 was approved by CEN as a European Standard without any modification. Page 3 EN 29090 : 1992 Gas tightness of equipment for gas welding and allied processes 1 Sc
10、ope This International Standard specifies the maximum external leakage rates which are acceptable for equipment used for welding, cutting and allied processes. It applies to individual components which are used in the gas supply to a blowpipe from the connecting point of the hose (outlet of the cyli
11、nder valve or connecting point to a gas supply piant). It does not apply to gas supply plants. 2 Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this International Standard. At the time of publication, the editions indic
12、ated were valid. All standards are subject to revision, and parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the standards listed below. Members of IEC and IS0 maintain regkters of currently valid Interna
13、tional Standards. IS0 2503 : 1983, Fressure regulators for gas cylinders used in welding, cutting and allied processes. IS0 3821 : 1977, Welding - Flexible hoses for gas welding and allied processes. 3 Definition For the purposes of this International Standard, the following definition applies. exte
14、rnal gas leakage: Undesired escape of gas to the atmosphere. 4 Expression of leakage The maximum permissible external leakage rates which are specified in this International Standard are total leakage rates for a complete component including inlet connections. These rates are given in cubic centimet
15、res per hour) of the gas for which the equipment was designed, corrected to standard conditions21, measured at room temperature. NOTE - Connections that are necessary only for the test are excluded. 5 Gas to be used for the tests Devices to be used with helium shall be tested with helium and devices
16、 to be used with hydrogen shall be tested with hydrogen or helium. Devices to be used with other gases shall be tested with dry oil- free air or nitrogen. If the test is carried out with a gas other than the gas for which the equipment is designed, appropriate corrections shall be made (see annnex A
17、). 6 Test pressure 6.1 Regulators Regulators shall be tested at pressures pl and pp as defined in IS0 2503. 6.2 Other equipment 6.2.1 Type tests Other devices shall be tested at the following pressures: ai maximum working pressure as given by the manufac- turer: b) 10 % of the maximum working pressu
18、re. 6.2.2 Routine tests All devices shall be tested at that pressure (of the two pressures specified in 6.2.1) which gave the most unfavourabie results during the type tests. 7 Maximum permissible leakage rates NOTE - The leakage rate for individual devices will be incorporated directly in the relev
19、ant standards for that device when they are revised. 7.1 Regulators Regulators shall not have a total leakage rate greater than 10 cm3/h. 1) 1 cm3/h = 0,28 x IO- m3/s 2) Standard conditions: 23 0C/1,013 bar (0,102 3 MPa). CEN EN*29090 92 W 3404589 0028961i 2 Page 4 EN 29090 : 1992 7.2 Blowpipes With
20、 the gas hose connected to one of the inlet connections, blowpipes shall be submitted to the following test: a) Close off the nozzle and the other inlet connection and half-open both the valves. Permissible leakage rate: 8 cm3/h % Test gas b) Close off the nozzle and open the second inlet connec- ti
21、on; half-open valve 2 and close valve I. Permissible leakage rate: 4 cm3/h 1 + Test gas c) nozzle; close valve 2. Close off the second inlet connection and open the 7.5 Devices with combined functions Devices with combined functions shall have a total leakage rate not exceeding the maximum rate appl
22、icable to any individual function. 7.6 Other equipment Other equipment which may be used on an installation for gas welding and allied processes shall not have an overall leakage rate greater than 8 cm3/h. 7.7 Hoses Hoses shall conform to the requirements laid down in IS0 3821 in terms of the leakag
23、e rate and/or gas permeability. 8 Measurement of the leakage rate The method described below is used to determine the leakage rate of a device; it is a type test method which determines whether a device conforms to the requirements specified in clause 7. For routine purposes, manufacturers may use w
24、hatever method is most suited to their requirements. 8.1 Immersion of the device.to be tested in water, with the device connected to a gas source throughout the test; collection of the gas leaking from the device in a graduated cylinder initially full of water. Other test methods are permitted, prov
25、ided that it can be shown that these give results as accurate as those available from the method given in this clause. Principle of the test method Permissible leakage rate: 4 cm3/h 8.2 Test apparatus (see the figure) (-e+ Test gas NOTE - This test procedure enables total leakage and leakage through
26、 each valve to be tested. 7.3 Safety devices Safety devices shall not have a total leakage rate greater than 8 cm3/h. 8.2.1 Water-bath, having suitable dimensions for complete immersion of the device to be tested. 8.2.2 Gas supply, allowing pressurization of the device throughout the test. 8.2.3 Gra
27、duated cylinder, initially full of water, mounted above the device to be tested. The size and scale graduations of the graduated cylinder shall be such that the volume can be read to an accuracy of 0,5 cm3. 8.2.4 Funnel, allowing the escaping gas to be collected. The funnel shall be suitable to coll
28、ect all the gas which may escape from the device, but not that which escapes from the connection with the gas supply pipe. 8.3 Procedure 7.4 Quick-action couplings Connected quick-action couplings shall not have a total leakage rate greater than 10 cm3/h. 8.3.1 Connect the device to be tested to the
29、 gas supply (8.2.2), all other possible openings being closed so that the leakage rate may be determined. CEN EN*29090 92 m 3404589 00289b2 4 m 8.3.2 Immerse the device in the water-bath (8.2.1) to a depth of at least 20 cm and supply the device with gas at a pressure equal to the test pressure, as
30、given in clause 6, plus the pressure Ap due to the immersion depth. 8.3.3 Wait 10 min to allow the trapped air adhering to the outside surfaces of the device to escape, then place the graduated cylinder (8.2.3) and the funnel (8.2.4) in position and maintain the device under pressure for 1 h. Page 5
31、 EN 29090 : 1992 8.3.4 At the end of the test, raise or lower the graduated cylinder so as to equalize the levels of the water in the tube and in the bath; measure the volume of collected gas by reading the graduation on the tube. 8.3.5 Correct the measured volume, as specified in clauses 4 and 5, t
32、o take into account the gas and the standard tem- perature and pressure conditions. - Graduated cylinder (8.2.3) .- Funnel (8.2.4) Device to be tested Test pressure Gas supply . Water-bath (8.2.1) Figure 1 - Test apparatus CEN EN*29090 92 W 3404589 00289b3 b W .)?age 6 EN 29090 : 1992 Annex A (norma
33、tive) Correction of measurements If the tests are not carried out with the gas for which the device is designed, the measured leakage rate shall be multiplied by the appropriate correction factor given in the table. Correction factor for the leakage rate measured Gas used for the tests Air I Oxygen I Nitrogen I Argon I Hydrogen I Helium I Acetylene I Air I 0,950 I 1,02 I 0,852 I - I - I 1.05 I I Nitrogen I 0,983 I 0,930 1 1
