EN 16447:2014

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Eksplozijsko izolacijski ventiliRückschlagklappen zur explosionstechnischen EntkopplungClapet d'isolation d'explosionExplosion isolation flap valves23.060.50Blokirni ventiliCheck valves13.230Varstvo pred eksplozijoExplosion protectionICS:Ta slovenski standard je istoveten z:EN 16447:2014SIST EN 16447:2014en01-oktober-2014SIST EN 16447:2014SLOVENSKI
STANDARD
EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 16447
July 2014 ICS 13.230; 23.060.50 English Version
Explosion isolation flap valves
Vanne à clapet d'isolation d'explosion
Rückschlagklappen zur explosionstechnischen EntkopplungThis European Standard was approved by CEN on 28 May 2014.
CEN members are bound to comply with the CEN/CENELEC 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 CEN-CENELEC Management Centre or to any CEN 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 CEN-CENELEC Management Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre:
Avenue Marnix 17,
B-1000 Brussels © 2014 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 16447:2014 ESIST EN 16447:2014

1 Scope This European Standard describes the general requirements for flap valves used for dust explosion isolation. An explosion isolation flap valve is a protective system, which prevents a dust explosion from propagating via connecting pipes or ducts into other parts of apparatus or plant areas. An explosion isolation flap valve can only stop the propagation of a dust explosion when it propagates against the direction of the normal process flow. It does not stop explosions running in the normal process flow direction. This European Standard specifies methods for evaluating the efficacy of explosion isolation flap valves. This European Standard is applicable only to explosion isolation flap valves which are intended to avoid explosion propagation from a vessel, into other parts of the installation via connecting pipes or ducts. The standard covers isolation of such vessels that are protected by explosion venting (including flameless venting), explosion suppression or explosion resistant design. NOTE 1 This standard is only applicable to cases where the explosion starts in a vessel and not in pipes or ducting. Explosion isolation flap valves are not designed to prevent the transmission of fire or burning powder transported by the normal process flow. NOTE 2 It is necessary to take this into account in risk assessments. This European Standard is only applicable for dust explosions. This European Standard is not applicable for explosions of materials listed below, or for mixtures containing some of those materials: a) gases, vapours and hybrid mixtures; b) chemically unstable substances; c) explosive substances; d) pyrotechnic substances. 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 13237, Potentially explosive atmospheres - Terms and definitions for equipment and protective systems intended for use in potentially explosive atmospheres EN 14373, Explosion suppression systems EN 14460, Explosion resistant equipment EN 15089, Explosion isolation systems SIST EN 16447:2014

a)
b) Key 1 fan 2 explosion isolation flap valve 3 vessel Figure 1 — Push flow situation SIST EN 16447:2014

Figure 2 — Pull flow situation 4 Explosion isolation flap valves 4.1 General An explosion isolation flap valve is a protective system, which prevents a dust explosion from propagating via connecting pipes or ducts into other parts of apparatus or plant areas. It is installed such that the normal process air flow passes in one direction through the valve and keeps it open. It closes when the air flow reverses due to a dust explosion event. The valve shall stay closed long enough to avoid flames from transmitting during an explosion event (see Note 1). Explosion isolation shall also be ensured during periods without process flow. NOTE 1 Re-opening of the valve is possible e. g. due to pressure oscillations caused by the fan or the venting process. Explosion isolation flap valves are designed to be connected to ducting. The valve housing is fitted with inlet and outlet connections to connect with the ducting. NOTE 2 Adapters are often used to connect to an oversize valve. 4.2 Mechanical integrity Any part of an explosion isolation flap valve shall be constructed such that it can withstand the loads imposed by any explosion that can be expected in accordance with its intended use, without losing its ability to perform its safety function. The construction can be either explosion-pressure resistant or explosion-pressure shock-resistant in accordance with EN 14460. NOTE The explosion pressure acting on the explosion isolation flap valve may be higher than the (reduced) explosion pressure in the connected vessel as a result of pressure piling and/or flame acceleration through the ducting. 5 Experimental testing of efficacy and mechanical integrity 5.1 General The testing shall reflect the intended use. As a minimum the following information is necessary prior to testing: SIST EN 16447:2014

Functional testing. Explosion isolation flap valves shall in principle be tested according to all three modules but where possible the modules can be combined. If a combination is chosen, the critical test conditions from the various modules shall be covered in the combination. For an untested new explosion isolation flap valve module C shall always be carried out. 5.2.2 Module A: Explosion resistance testing Explosion resistance shall be confirmed by explosion testing according to the following procedure: 1) Test arrangement: • The explosion isolation flap valve is mounted to a test vessel according to Figure 3. The explosive atmosphere inside the test vessel and the pipe connecting the valve may be of any type (gas or dust), provided the pressure generated is sufficient to subject the valve to the required pressure. The SIST EN 16447:2014

Key 1 Test vessel 3 Pressure Transducer (Pt) 2 Explosion Isolation Flap Valve 4 Explosion vent Figure 3 — Test arrangement for explosion pressure resistance testing 5.2.3 Module B: Flame transmission testing The main objective of the flame transmission testing is to verify that the explosion isolation flap valve is able to prevent explosion flames from propagating past the explosion isolation flap valve. The tests shall expose the explosion isolation flap valve to the maximum reduced explosion overpressure as indicated in the intended use and a lower one (see “3) number of tests”) and shall include conditions where the valve is open and closed. If there is a locking mechanism it shall not be locked in the closed position before ignition. 1) Test arrangement:
• The test arrangement shall be similar to the one shown in Figure 4. The size of the vessel shall reflect the intended use of the device. The explosive atmosphere in the vessel shall represent an explosibility similar to the highest KSt as specified by the intended use. It has to be assured that the flame reaches the position of the valve. The test arrangement shall include a duct in case it is expected t
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