Sprayer Depot Blog

 Contributed by Guest Blogger:  Mark Techler, Factory Representative-Hypro

Diaphragm Pumps

Since the 1980s diaphragm pumps have been used to pump agricultural and industrial liquids at higher pressures than are available from centrifugal, roller, or gear pumps.

Diaphragm pumps also self-prime, handle abrasive liquids, and can be coupled to gas engines with gearboxes, making them ideal for portable spraying applications. The traditional materials of construction of the liquid handling parts of these pumps has been anodized aluminum or plastic coated aluminum. While this construction is adequate for many spray materials, there are aggressive caustic and acid based spray materials now being used that will attack aluminum regardless of how it is coated, in a matter of months.

Features & Benefits of Poly Head Diaphragm Pumps

Hypro poly head diaphragm pumps are now available for these applications. The heads, manifolds, fittings, and control units are made from corrosion resistant polymers.

You can use “polypropylene” on corrosion resistance charts to check compatibility with the liquid you are pumping. Valves are made from PVDF (Kynar) and 303 stainless steel. The heads and manifolds are held to the pump body by stainless steel fasteners. These pumps are field proven to last significantly longer than aluminum head pumps in these demanding applications.

Hypro models DP423 and DP573 are rated at 11 gpm and 15 gpm with maximum pressure of 250 psi. A gearbox is available for mounting the pump on a 5.5 hp engine and a control unit includes a plastic relief valve, stainless ball valves to control agitation and main flow, and a pressure gauge. The hex shaped suction and discharge manifolds are hydraulically efficient and are easier to maintain than triangle shaped manifold systems. The oil bath lubricates the crankcase and provides hydraulic support for the diaphragms. This setup is ideal for truck mounted spraying of aggressive liquids.