In order to ensure a complete and safe gas supply, it is necessary to control the pressure at the inlet to the consumer device. The primary function of the gas regulator is to serve as a device that reduces high pressure to a more useful lower pressure. Gas pressure regulator ZR 20 is intended for adjusting the gas pressure for household appliances that use gas. It is necessary for the gas pressure regulator to meet the requirements of DIN 33822. In this case, it was necessary to perform an analysis of the stress and displacement of the lower part of the housing of the regulator. The geometric model is designed in SOLIDWORKS, and numerical analysis is performed by applying the finite element method implemented in the software package SOLIDWORKS Simulation. This housing is made of sheet steel, so it is necessary to perform stress and displacement analysis for the limit values of the bending moment and check the displacements of the housing in terms of the allowable change in the angle of the connection. In addition, it is necessary to model a new cast imaginary lower housing that can be mounted on the existing gas pressure regulator ZR 20. For the cast housing it is also necessary to perform stress and displacement analysis for bending moment limits and check the change of connection angle. It is necessary to compare the results of the analysis of these two housings and conclude why the cast housing, compared to the standard, would be given an advantage over the existing housing of the gas pressure regulator.