1、CEN EN*28659 90 w 3404589 0034580 20T EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 28659 December 1990 UDC 621.646-036.073 : 620.169.1 Descriptors: Plastics, thermoplastics resins, cocks, torque, fatigue tests, fatigue life English version Thermoplastics valves - Fatigue strength - Test meth
2、od (IS0 8659 : 1989) Robinets en matriaux thermoplastiques - Rsistance la fatigue - Mthode dessai (IS0 8659 : 1989) Armaturen aus Thermoplasten - Ermdungsf estigkeit - Prfverfahren (IS0 8659 : 1989) This European Standard was approved by CEN on 1990-11-08. CEN members are bound to comply with the CE
3、NXENELEC 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
4、any GEN member. This European Standard exists in three official versions (English, French, German). 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.
5、 CEN members are the national standards bodies of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CEN European Committee for Standardization Comit Europen de Normalisation
6、Europisches Komitee fr Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels O 1990 Copyright reserved to CEN members Ref. No. EN 28659 : 1990 E CEN ENm28657 90 W 3404587 003458L L4b W Page 2 EN 28659 : 1990 Foreword Based on the positive result of the Formal Vote procedure, the Internati
7、onal Standard IS0 8659 : 1989 Thermoplastics valves - Fdtigue strength - Test method is adopted as a European Standard. In accordance with the Common CENKENELEC Rules, the following countries are bound to implement this standard: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland,
8、Ireland, Italy, Luxembourg, Netherlands, Nonvay, Portugal, Spain, Sweden, Switzerland and United Kingdom. CEN ENx28659 90 3404589 0034582 082 Page 3 EN 28659 : 1990 Thermoplastics valves - Fatigue strength - Test method 1 Scope This International Standard specifies the endurance test necessary to co
9、nfirm the ability of hand-operated plastics valves to withstand prolonged use, with repeated opening and closure. It dues not specify the ability of valves to withstand adverse conditions, in particular those of chemically agressive fluid media and/or environments, or excessive fluid velocities and
10、cavitation. This International Standard includes values of the parameters necessary for the proper performance of the endurance test, with the reservation that parameters may be different in par- ticular product standards see 5.1). 2 Normative references The following standards contain provisions wh
11、ich, through reference in this text, constitute provisions of this International Standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this International Standard are encouraged to investigate the possibilit
12、y of applying the most recent editions of the standards listed below. Members of IEC and IS0 maintain registers of currently valid International Standards IS0 161-1 ; 1978, Thermoplastics pipes for the transport of fluids - Nominal outside diameters and nominal pressures - Part 7: Metric series. IS0
13、 6708 ; 1980, Pipe components - Definition of nominal size. IS0 7005-2 : 1988, Metallic flanges - Part 2: Cast iron flanges. IS0 7005-3 ; 1988, Metallic flanges - Part 3: Copper alloy and composite flanges. 3 Definitions For the purposes of this International Standard, the following definitions appl
14、y. 3.1 nominal pressure PN) : An alphanumerical designation of pressure, used for reference purposes, which is related to the mechanical strength of the valve. Usually it corresponds to the pressure of water at 20 OC, in bars, for which the valve is designed (see also IS0 161-1). 3.2 tightness at th
15、e nominal pressure. closing torque: Torque required to close a valve to full 3.3 fluid velocity: The velocity of a fluid in a pipe connected to a valve of nominal size equivalent to the nominal diameter of the pipe. 3.4 be the reference dimensions: reference dimensions: The following are considered
16、to - nominal size DN (see IS0 6708) for flanged systems see IS0 7005-2 and IS0 7005-3); - nominal outside diameter D for tubes see IS0 161-1). 4 Apparatus Test apparatus, capable of testing the whole valve assembly with its obturator mechanism. Furthermore, it shall include ap- propriate devices to
17、perform each step separately, or con- tinuously and automatically. The test apparatus shall include appropriate means to discon- tinue the test cycle during the pressure period and to maintain the pressure in the closed position. Page 4 EN 28659 : 1990 Pressure gauges shall be accurate to within f 1
18、 % of the full- scale reading. Temperature sensors shall be accurate to within f 2 OC. NOTE - Attention is drawn to the need for adequate safety precau- tions when using compressed air or gas for this test. 5 Procedure 5.1 Test requirements to be taken from product standards The following specificat
19、ions shall be taken from the particular product standard. a) any tests which shall be performed before the endur- ance test, and those which shall be repeated after comple- tion of the endurance test; b) whether tightening of the gland packing (if used) during the endurance test is allowed; c) accep
20、tance criteria for tests; d) the number of specimens to be tested; e) the number of test cycles to be performed; f) the fluid used for the test, and its temperature, pressure and velocity; g) the ambient temperature. 5.2 Endurance test The endurance test, using water, air or gas as the fluid medium,
21、 at the temperature, pressure and velocity specified in the particular product standard, shall be carried out, at the am- bient temperature specified in the product standard, as follows. 5.2.1 Open multiple-turn valves to the fully open position at a hand-wheel speed of 40 r/min f 10 r/min for valve
22、s of nominal size up to DN 50 and 20 r/min k 10 r/min for valves of nominal size greater than DN 50. For quarter-turn valves, the opening time shall be not less than 2 s for valves of nominal size up to DN 50 and not less than 4 s for valves of nominal size greater than DN 50. The valve shall be lef
23、t in the open position for at least 5 s, but not longer than 20 s. 5.2.2 Close multiple-turn valves at a hand-wheel speed of 40 r/min I 10 r/min. For quarter-turn valves, the closing time shall be not less than 1 s. 5.2.3 Closing shall be performed using the torque specified in the particular produc
24、t standard. During opening and closing, there shall be no visible leakage at any seal. 5.2.4 After the valve has been closed, an internal pressure shall be applied as specified in the particular product standard. The valve shall be left in the closed position for at least 5 s, but no longer than 20
25、s. 5.2.5 The valve shall be opened as described in 5.2.1. 5.2.6 The test procedure described in 5.2.1 to 5.2.5 shall be repeated for as many cycles as required by the particular prod- uct standard. 6 Test report The test report shall include at least the following information : a) a reference to thi
26、s International Standard and to the product standard ; bl a complete identification of the valve, giving the follow- ing information : 1) the material of the valve body, 2) the nominal size (DN) and the socket diameter or spigot diameter, 3) the nominal pressure (PN) of the valve, 4) the manufacture
27、rs name or trade mark, 5) the type of pipe used, 6) if necessary, the flow direction, 7) the closing torque; c) a description of the test conditions; d) the number of specimens tested; e) whether the valve complied with the test requirements if the valve failed (leakage or fracture) indicate under what conditions it failed; f) any operation not laid down in this International Stan- dard, or other occurrences which may have affected the test results; g) the date of the test.
