1、DI NI Sandaird re steam, autamatic: equipment, ciaxifieatim! This. European, Stcamlardi was approvedi by CENI on1 ll-O9-3 anid IS identical tto: the ISQ, Standardasreferred to. CEN memtxsrc are bound tcc CQM with the CEN/CEMEILEG: internali Reguladione which- stipulate thle cmditiano fcrr giuing thi
2、s Eurupean- Standard the status af a national standard without any altemion- Up-to-dat lists anll referemes mmemingi such- rratimal stmd”sds may. be obtained 01311 applicatiorr ta the CntrdiSmretariat or t my Grni mber. This Europeani Standard ekiets in tkm afficizi vessians (iEnglrchl Frenchb Germa
3、m)! A ve Sion1 in aw othm ianguagg m clkssifiaaom ta FarmaliVate The result was positiv Jirectiung of luidifiow 1 Defarmble Klassifikation (IS0 6704 : 1982) European Standard EN 26 704 : 1991 has the status of a DIN Standard. National foreword This standard has been published in accordance with a de
4、cision taken by CEN/TC 69 to adopt, without alteration, Interna- tional Standard IS0 6704 (prepared by ISO/TC 153) as a European Standard. The responsible German body involved in the preparation of this standard was the Normenausschu Armaturen (Valves Standards Committee). The DIN Standards correspo
5、nding to the International Standards referred to in clause 2 of the EN are as follows: International Standard DIN Standard IS0 6553 DIN IS0 6553 IS0 6554 DIN EN 26 554 Standard referred to (and not included in References) DIN EN 26 554 Flanged automatic steam traps; face-to-face dimensions Internati
6、onal Patent Classification F 16 T 1 /O0 EN comprises 6 pages. Beuth Verlag GmbH, Berlin, has the exclusive right of sale for German Standards (DIN-Normen). DIN EN 26 704 Engi. Price group 6 06.93 Sales No. 1106 EUROPEAN STANDARD EUROPISCHE NORM NORME EUROPENNE EN 26704 September 1991 UDC 621.646.9.0
7、57.6 : 621.186.6 : 001.4 Descriptors: Valves and fittings, traps, drainage, water vapour, steam, automatic equipment, classification. English version Au tom at ic steam traps Classification (IS0 6704 : 1982) Purgeurs automatiques de vapeur deau; classification (IS0 6704: 1982) Kondensatableiter; Kla
8、ssifikation (IS0 6704 : 1982) This European Standard was approved by CEN on 1991-09-30 and is identical to the IS0 Standard as referred to. CEN members are bound to comply with the CENICENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a natio
9、nal 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 CEN member. This European Standard exists in three official versions (English, French, German). A ver- sion in a
10、ny 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 offi- cial versions. CEN members are the national standards bodies of Austria, Belgium, Denmark, Finland, France, Germany, Greece, I
11、celand, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CEN European Committee for Standardization Comit Europen de Normalisation Europisches Komitee fr Normung Central Secretariat: rue de Stassart 36, 8-1050 Brussels O 1991. Copyright reserv
12、ed to all CEN members. Ref. No. EN 26 704: 1991 E Page 2 EN 26 704 : 1991 Foreword On the proposal of CEN/TC 69, CEN/BT decided to submit International Standard IS0 6704 : 1982 Automatic steam traps; classification to Formal Vote. The result was positive. In accordance with the CENICENELEC Internal
13、Regulations, the following countries are bound to implement this European Standard: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Nor- way, Portugal, Spain, Sweden, Switzerland and United Kingdom. Endorsement notice The text of the Int
14、ernational Standard IS0 6704:1982 was approved by CEN as a European Standard without any modification. Page 3 EN 26 704 1991 1 Scope and field of application The purpose of this International Standard is to establish a simple classification of the main types of automatic steam traps according to the
15、 mode of actuation of their obturation device and disregarding their details of conception and construction. 2 References IS0 6552, Automatic steam traps - Terminology. IS0 6553. Automatic steam traps - Marking. IS0 6554, Flanged automatic steam traps - Face-to-face dimensions. 3 Definition For this
16、 International Standard, the following definition applies : automatic steam trap : Self-contained valve which automatically drains the condensate from a steam-containing enclosure whilst remaining tight to live steam or, if necessary, allowing steam to flow at a predetermined rate. 4 Classification
17、The types of traps defined hereunder are classified according to their mode of actuation; other traps, combining these different types (or of a new design) may be developed, but these traps shall not be regarded as a characteristic type of automatic steam traps in the sense of this International Sta
18、ndard. If one considers the mode of actuation of the obturation device, three categories of automatic steam traps can be distinguished : - (4.1); - thermostatic traps, actuated by the temperature of condensate (4.2): mechanical traps, actuated by the level of condensate - thermodynamic traps, actuat
19、ed by fluid dynamics (4.3). Page 4 EN 26 704 : 1991 Sketch (diagrammatic) 4.1 Mechanical traps (float traps) (actuated by the level of condensate) 4.1.1 Steam trap with closed float Direction of fluid flow I I+- -I- 4.1.2 Steam trap with open top float :i 4.1.3 Steam trap with open inverted float 5
20、r- 3 2 1 Closed float 2 Obturator 3 Lever 4 Seat 2 1 Float (bucket type) 2 Obturator 3 Lever 4 Siphon 5 seat Direction of fluid flow 3 - 4 - 4 7 4- 1 Open inverted float 2 Obturator 3 Lever 4 Vent hole 5 Seat ction of flow Operation The opening or closin, movements of the obturatc are caused by the
21、variation of the level of condensate il the trap shell. The opening or closin novements of the obturato ire caused by the variation: If the level of condensate ir :he float. he opening or closing novements of the obturator ire caused by the variations if the level of condensate in he float. Page 5 E
22、N 26 704 : 1991 Sketch (diagrammatic) .2 Thermostatic traps ictuated by the temperature of condensate) .2.1 Vapour pressure trap Iirection uid flow of 1 7 I- I/ 1.2.2 Bimetallic or thermoelastic trap 1 7 4 77 1 Deformable element 2 Obturator 3 Seat 1 Bimetallic element 2 Obturator 3 Seat Direction o
23、f -fluid flow L 1 Expansible element 2 Obturator 3 Seat Operation The opening or closing movements of the obturator are actuated by imbalances created between the pressure of condensate in the trap and the vapour pressure of the volatile liquid contained in a deformable element. The temperature chan
24、ges of the incoming condensate cause the deformation of the bimetallic or thermoelastic element, and consequently the opening and closing movements of the obturator. The opening or closing movements of the obturatoi arecaused by the temperature variations of the condensate acting on an element with
25、i high thermal expansion coef. ficient. Page 6 EN 26 704 : 1991 Sketch (diagrammatic) 4.3 Thermodynamic traps (actuated by fluid dynamics) 4.3.1 Obturator trap 3 2 r Direction of fluid flow -* 4.3.2 Impulse trap 4 7 Direction fluid flow of 1 Obturator 2 Pressure chamber 3 Seat 1 Obturator (piston va
26、lve) 2 Pressure chamber 3 Seat 4 Decompression orifice 4.3.3 Labyrinth or orifice trap 1 Orifice (one or more) 2 Adjustable obturator Direction of fluid flow - * Operation The successive differences of pressure between the inlet and the pressure chamber cause the opening or closing movements of the obturator. The successive differences of pressure between the inlet and the pressure chamber cause the opening or closing movements of the obturator (piston valve). Fluids pass freely through the wifice. Condensate may sliminate or reduce the flow Df steam or non-condens- ables.
