Valve cover and valve gate of diaphragm gas meter

The invention discloses a valve cover and a valve gate of a diaphragm gas meter. A sliding contact plane is arranged between the lower end face of a valve cover and the upper end face of the valve gate; wherein the upper end surface of the valve cover is provided with a guide bulge which is in guide fit connection with a guide rod frame fixed on the machine core body, and the valve cover slides back and forth along the guide rod frame; wherein the valve gate is fixedly arranged on the machine core body and is provided with an airflow channel for switching and supplying air to two metering cavities of each metering chamber of the machine core body; the sliding contact structure is characterized in that the surface roughness Ra of the sliding contact plane is 0.1-0.3 [mu] m. The valve cover and the valve gate of the diaphragm gas meter have the advantages that the sealing performance of a sliding contact plane can be maintained for a long time, and therefore stable metering precision can be kept for a long time