Measure the distance between pipes or pipe fittings that you wish to join together with a tape measure to determine the length of flex hose needed to make the connection. If mounting hard-to-plumb areas where the pipe must bend, then bend the tape along the route to account for the excess pipe needed to cover the distance.
Mark the measured length onto a piece of flex hose with a black marker.
Cut the hose along the marked line using a hacksaw. Remove any burrs left on the end of the hose after cutting by scraping the inside and outside hose edge with a utility knife.
Brush the end of the flex hose with PVC primer to clean the surface and soften the hose slightly in preparation for joining. Apply the solvent on the end of the hose for a length equal to the inside of the fitting to which you’re connecting the hose, plus 2 inches. Place the primer inside the pipe fitting as well, extending it to the end of the fitting collar where the end of the hose will rest. Use the attached brush that came with the primer bottle. Allow the primer to set until you can scrape a thin layer of PVC off the interior surface of the fitting with a sharp utility knife blade.
Cover the primer with a moderate layer of PVC cement, both on the hose end and inside the fitting. Use the cement’s included brush. Push the hose into the fitting until the end of the hose reaches the end of the fitting collar. Allow the pieces to cure together for 12 hours before using the new connection.