Rola-Chem 570381V 4" PVC 175-500GPM Vertical Mount Flowmeter Designed to be compatible with practically every existing flowmeter, replace your old clogged flowmeters with these accurate, easily serviced units from Rola-Chem. Rola-Chem flowmeters are built to withstand water temperatures up to 200°F and are manufactured to work with schedule 40 PVC pipe.