This publication represents a basic standard for safe operation, substantial and durable construction, and acceptable performance of natural gas operated diaphragm pumps. It is the result of years of experience in the manufacture, testing, installation, maintenance, inspection and research on natural gas operated diaphragm pumps designed for the utilization of gas. There are risks of injury to persons inherent in some appliances that, if completely eliminated, would defeat the utility of the appliance. The provisions in this Standard are intended to reduce such risks while retaining the normal function of the appliance.