supply of supply of a set of flash back arrestors (dry type) , supply of a set of flash back arrestors (dry type) suitable for use in oxy-fuel gas cutting/wel ing systems, for both oxygen and fuel gas (acetylene/lpg/bcg) lines, for installation at torch end and regul ator end, to prevent flash backs. the flash back arrestors shall conform to en 730 / iso 5175-1 / is 11006:2 011 (ra-2021), amendment-1 of december 2013 standards. one set shall consist of four (04) numbers of fl ash back arrestors, comprising one(01) number for oxygen regulator-end installation ,one(01) number for f uel gas (acetylene/lpg/bcg) regulator-end installation, one (01) number for torch-end installation for oxyg en supply and one(01) number for torch-end installation for fuel gas (acetylene/lpg/bcg) , as applicable. t he flash back arrestor shall be provided with flame arrestor (fa) and non-return valve (nrv) as minimum safety features. for regulator-end applications, the flash back arrestor shall additionally be provided with a thermal cut-off valve (tv). end connections shall be g 3/8 threads conforming to en 560 / iso 3253 stand ards, suitable for right-hand (rh) threads for oxygen line connections and left-hand (lh) threads for fuel ga s (bcg/acetylene/lpg) line connections, as applicable. the working pressure and configuration shall be suit able for oxygen lines (up to 15 bar) and fuel gas lines (1.5 bar for acetylene / 5.0 bar for bcg/lpg) as per a pplication. accepted makes shall be of messer / esab / gce / weldstar / ador/witt. offers shall be accepted only from oems or their authorized dealers. valid authorized dealership certificate shall be enclos ed. suppliers shall submit test certificates from a government-authorized test house. in case of internation al brands, test certificate from a reputed institute such as bam, germany is mandatory. suppliers shall pos sess in-house facilities for testing and calibration of flash back arrestors. the purchaser reserves the right t o inspect these facilities. note: four (04) samples shall be supplied in advance and suitability approval from the consignee shall be obtained before commencement of production and bulk supply. [ warranty period : 12 months after the date of delivery ] ]