Ball valves made of brass, being convenient to install and operate, are widely used in heat, water and gas supply systems. End consumers are usually citizens in whose homes, garages and cottages these products are installed. Until recently, the quality of these products was not confirmed by a certificate of conformity. But at a relatively low cost, damage from its failure can amount to hundreds of thousands and even millions of rubles. The authors of this article consider whether there is a potential opportunity for unscrupulous market participants to circumvent the new standard for assessing the conformity of brass ball valves.