BS 669-1:1989 pdf free download.British Standard Flexible hoses, end fittings and sockets for gas burning appliances Part 1. Specification for strip-wound metallic flexible hoses, covers, end fittings and sockets for domestic appliances burning 1 st and 2nd family gases.
1 Scope
This Part of BS 669 specfies type test retiuirements for stiip•wounci metallic tiexible hoses, covers, UIHJ fittings and sockets for use with domestic cookers and applianceG burning 1st and 2nd family gases at a nominal inlet prcciir of 20 mbar’.
The requirements for strip-wound flxihle hoses with erd fittinjs attached arc specified In section two. Sectiuii thiee
electroplated with a zinc coating, which shall be not less than 0.0025 mm thick prior to forming.
5,2 Sea 1mg thread/rubber packing
5.2.1 Requirements. The thread shall comply with 5.2.2, 52.3 and either 5.2.4.1 or 5.2.4.3.
5.2.2 GompositIon. The thread shall be made from d ,iew first- grade natural, butyl or nitrile rubber or a blend of those materials, suitably compounded and vuleanized, and shall have a relative density not exceeding 1.02. The mix shdll nut contain wiy wtsstH or reclaimed rubber.
NOTE The composition may includo accelerators and non-oxidants,
S1 Finn gation
5.2.3.1 flequirwnent. The average extension of a 150 mm gaugo Length in each of two test specimens of the thread measured immediately after the application of a 1.5 N/mm2 stress shall be not less than 250 rum aeid not more than 650 mm when tested fiB described in accordance with 5.2.3.2. p The cross-sectional area of the thread shall be measured in the unstressed condition.
5.2.3.2 Mothod. Suspond two 250 mm lengths of thread from a suitah!e orip. Gradually apply a load oroducinq a stress of 1.b N/mm2 to each loncjth. Closely iiiuniLor the application of the loads so that the extension rates of the lengths of the thread are approxImately 40 mm/s. Measure the extension of
7.2 Construction
7.2.1 Brass rod shall show no evidence of cracking when tosted in accordance with appendix r of OS 2874: 1980.
7.2.2 Gas carrying parts of the encf fitting and socket shall have smooth external surfaces without prominent imperfections. Machined surfaces, e.g. sealing surfaces, shall have a fine finish free from scores and tool marks. The surface texture of Useal housing grooves and associated surfaces shall comply with BS 4518.
7.2.3 There shall be no burr, flashing, sharp edge orswarf on any part of the end fitting or socket that will aflect its operation.
7.3 Materials
7.3.1 BrassesinaccordancewithCZ 121 orCZ 131 otBS 2874 with a lead content of 3 % or less shall be used for swaged components. Other gas carrying components of the end fitting and the socket shall be made from one of the following:
ta) brass in accnrdanc with gride (7 112 C 121 or CZ 131 of 85 2874 or brass in accordance with grade CZ 122 of BS 2872;
(b) stainless steel in accorcidnce with yrdde 321S31 of BS 970: Part 1.
For non-gas carrying parts other materials shall be suitable for tnmpratiirns of 95 t without detriment to the operation of the flexible connection assembly. Such parts shall comply with 6.1.2.6.
7.3.2 Circlips shall comply with BS 3673: Part 1 and shall be of steel complying with BS 144: Part 1. and be zinc plated, or of stainless 5teel spring-wire complyiii with 85 2056.
7.3.3 rings shallcomply with BS 1806 orBS 4518 and be of rubber corWound BA 70 in accordancowith BS 2751 & 3222.
7.3.4 Valve springs shall be of stainless steel complying with R 2flA
7.3.5 Seali9g wastors shall not contain asbestos.
9.3 Impact test
9.3.1 Requirement. When tested In accordance with 9.3.3, using the apparatus described in 9.3.2, the end fitting assembly shall comply with 9.1.2 and any socket shall comply with 9.1.1. There shall be no cracks that are visiblo to tht Ildked eye.
9.3.2 Apparatus. The apparatus shall consist of a hardened steel striker of 3 kg mass with a 12 mm diameter Nat end and a ligid smooth bore tube hi wliidi thu sti ike,, vvith dii uveidll clearance of not more than 0.5 mm, is free to slide (see figure 9).
9.3.3 iWeihud. Rigidly lix the inlet ul Lhe end liLting usseinbly, using its normal method of attachment, such that the axis of th mtting j’arts is hnri,nntal (sie figiir 10). IJsirig thA apparatus described in 9.3.2 and with the guide tube rigidly fixed in relation to, end resting on, the end fitting assembly, apply vertical blows to the end fitting with an impact energy as qiven in table b.
For straight end fittings, apply the blows to the highest point on the plug, e.g. plug ring/sleeve (see figure 10(a)). Apply four successive impacts, the assembly being rotated 90” ahoiit the horizontal axis hetween each impact.
For right-angled fittings, apply three impacts to the highest point on the inlet end of the plug, one impact when the outlet end is vertical and two further impacts, each one at 90 ° either side of the first, i.e. with the outlet end now horiioiital.
Finally, rotate the whole assembly such that the inlet end is vertical and apply a furthor blow to the outlet end as shown (see figure 1U(b)).
NOTE 1. Impect energy E(in J) mass of striker (in kg) .ccoivration duti to yraiity (In ms ‘I * htiyht of fall (in ni), i.e. forfittings below ¾, E —3 x 9.81 x 0.23 = 6.75 J; for size %and size ½ fittings. E 3 x 9.81 )C 3.46 = 13.6J.
NOTE 2. Thu rqiremonts for Dull given in 9.2.1 and impact givun in 9.3.1 re iritenidtd fur unupleW end fitliny uumnblius. Whuiu d manufactuier does not make the co,T1LIeIe assembly, test samples of thc appropriate matching part(s) should be provided by the manufacturer.