The ANSI/HI 7.8 provides piping and accessory requirements used in the installation of metering pumps, and to educate users about the effects and interactions of inlet (suction) and outlet (discharge) piping on metering system performance. This guideline applies to controlled volume metering pumps, specifically those with pulsating flows. Types of positive displacement pumps include, but are not limited to, hydraulic-coupled disc diaphragm, hydraulic-coupled tubular diaphragm, mechanical-coupled disc diaphragm, packed piston, and plunger.