The pressure regulator is designed for controlled pressure reduction of the transported medium in cold and hot water supply networks, compressed air pneumatic pipelines, as well as in technological pipelines transporting liquids and gases that are not aggressive to the product materials. The regulator maintains a pressure at the outlet that does not exceed the set value, regardless of pressure surges in the network (dynamic mode). In static mode, the pressure after the SE.555 series regulator also does not exceed the set value. Regulation occurs according to the scheme "after itself". The presence of a damping chamber reduces the limits of permissible deviations of the outlet pressure during sudden pressure surges at the inlet to the regulator.