BS EN ISO 7840:2018 pdf – Small craft – Fire-resistant fuel hoses.
1 Scope This International Standard specifies general requirements and physical tests for fire-resistant hoses for conveying petrol or petrol blended with ethanol and diesel fuel or diesel fuel blended with FAME, designed for a working pressure not exceeding 0,34 MPa for hoses with nominal bore up to and including 10 mm and 0,25 MPa for hoses up to 63 mm inner diameter in craft of hull length up to 24 m. It applies to hoses for small craft with permanently installed fuel systems. It does not apply to hoses entirely within the splash well at the stern of the craft connected directly to an outboard engine. Specifications for non-fire-resistant fuel hoses are given in ISO 8469  . Specifications for permanently installed fuel systems are given in ISO 10088. 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. ISO 3:1973, Preferred numbers — Series of preferred numbers ISO 1307, Rubber and plastics hoses — Hose sizes, minimum and maximum inside diameters, and tolerances on cut-to-length hoses ISO 1402, Rubber and plastics hoses and hose assemblies — Hydrostatic testing ISO 1817:2011, Rubber, vulcanized or thermoplastic — Determination of the effect of liquids ISO 7233:2006, Rubber and plastics hoses and hose assemblies — Determination of resistance to vacuum ISO 7326:2006, Rubber and plastics hoses — Assessment of ozone resistance under static conditions ISO 10088:- 1) , Small craft — Permanently installed fuel systems EN 14214:2008+Amd.1:2009, Automotive fuels — Fatty acid methyl esters (FAME) for diesel engines — Requirements and test methods 3 General requirements Hoses complying with this International Standard shall present a non-porous, smooth inner surface, free from defects and chemical contaminants.
5.5 Volume change in test liquids Determine the change in volume of the hose (tube and cover) by the procedure described in ISO 1817. Place the test pieces in test liquids as specified in 5.2 at a temperature of 40 °C ± 2 °C for 40 days. If the hose is made of a homogeneous compound (with or without reinforcement), the swelling shall not exceed 35 % by volume, as measured by displacement in water. For hose with an inner layer of fuel- resistant material and a cover of another material, mainly intended for weather and ozone resistance, the increase in volume shall not exceed 35 % for the tube and 120 % for the cover. 5.6 Mass reduction of test hose Determine the reduction in mass of the inner layer by the procedure described in ISO 1817. Fill three hoses or submerge test pieces from the hoses with test liquids, as specified in 5.2, and store them for 40 days in air at a temperature of 40 °C ± 2 °C. The reduction in mass of the inner layer shall not exceed 8 % of the initial mass of the test pieces. NOTE A reduction in mass of 8 % corresponds to a decrease in volume of approximately 10 %. 5.7 Fire resistance Test the hose in accordance with the method described in Annex A. 5.8 Effect of ozone The hose shall be tested as described in ISO 7326:2006, Method 1. The sample shall show no visible cracks at ×7 magnification. 5.9 Fuel permeation The permeation rate for the hoses shall be determined according to the method specified in Annex B or an equivalent test method. The hoses shall be classified in the following way and marked in accordance with Clause 6: Type 1: hoses with a permeation rate of 100 g/m 2 or less per 24 h.
5.11? Abrasion? test? —? 38? mm? and? larger? fuel-fill? hose? with? helical? wire? embedded? reinforcement Hose samples of 38 mm inner diameter shall be selected for the test. Larger bore hose sizes to be qualified by the test shall not have a cover thickness or construction less than those of the test samples. Three identical 38 mm bore hose samples shall be tested. Condition hose for at least 24 h at 23 °C ± 2 °C and 50 % ± 5 % relative humidity. The test hose shall be mandrel- (core-) supported and rotated at a constant speed of 80 r/min ± 2 r/min. Subject hose to a laterally moving abrasive surface, i.e. 80 grit aluminium oxide (Al 2 O 3 ) emery cloth, parallel to the longitudinal axis of the hose. The abrasive surface shall be (25 ± 5) mm × (75 ± 5) mm affixed to a hard surface which will cycle back and forth 75 mm ± 5 mm in each direction while loaded with a constant normal force of 45 N ± 5 N. One test cycle shall equal one 360° rotation of the outside diameter of the hose and one back and forth movement of the abrasive surface. After 1 000 cycles, the three test samples shall have no helical wire reinforcement exposed at the point of contact with the abrasive surface.