Silencers are noise reduction system devices which are commonly installed in the regulator as a remedy for noise pollution. Type SR Silencer is fitted near the regulator shutter and is highly efficient up to a theoretical speed of 80 m/s calculated at the outlet flange. Type SRS Silencer consists of a Type SR Silencer plus a widened outlet flange in which a second silencer is fitted. Type STL Silencer is specially developed to be introduced into ?T? couplings of piping. While Type STP Silencer, is fitted in the pipe and is secured with two flanges.