Pulsing Flow Coater

How can we get a constant paint flow from our flow coater?


Facebook Share Icon LinkedIn Share Icon Twitter Share Icon Share by EMail icon Print Icon

Q.  My company makes oil-filled transformers. Most of the tanks are corrugated for cooling, and a small number have cooling radiators attached. We found that we were not getting enough paint on the radiators and decided to flow coat them. We are now painting the tanks by spray painting and the transformer radiators by flow coating. After painting, we attach the radiators to the tanks.

Because such a small number of transformers have radiators, we couldn’t justify buying a flow coater, so we had our maintenance department build one using a diaphragm pump. The output nozzle allows enough paint to flow, but it is pulsating rather than constant. 

What can we do to get a constant flow? –G.P.

A.  What you really need is a hydraulic engineer, however, I believe there are two relatively inexpensive things your maintenance department can do. 

1. Replace the diaphragm pump with a rotary or centrifugal pump. You don’t want to run the pump too fast, because the high shear rate could change the rheology of the paint. 

2. Build an overhead tank having an outlet on the bottom. Suspend the tank from the plant ceiling. Pump the paint into the tank using your existing setup. Attach a hose to the tank-bottom outlet to supply paint to the flow coater nozzle. 


  • Masking for Surface Finishing

    Masking is employed in most any metal finishing operation where only a specifically defined area of the surface of a part must be exposed to a process. Conversely, masking may be employed on a surface where treatment is either not required or must be avoided. This article covers the many aspects of masking for metal finishing, including applications, methods and the various types of masking employed.

  • Paint Application Methods

    An overview of spraying, dipping, flow coating, and everything in between.

  • What is Electrocoating?

    E-coat can produce uniform finishes with excellent coverage and outstanding corrosion resistance.