They're also used to adjust water flow to allow proper flushing

They have a nozzle that delivers the water spray for more thorough

EZH20 IN-WALL-NO FILTER

18 Gauge Stainless Steel 29' x 18' x 5

40 provide a reserve margin for applications where intermittent overloading or fluctuating (high/low) voltage conditions may occur

Cash Valve Pressure Regulator, Bronze, 90 to 150 psi - 20253-0120 Specimen Cabinets & Healthcare Accessories They're also used to adjustThis PENTAIR CASH VALVE single seated, spring loaded, direct acting, diaphragm type valve helps reduce high initial inlet pressure; maintains pressure within reasonably close limits. FNPT connections.