New Plast-O-Matic Ball Valves Solve Linear Flow Rate Issues

What Can a Characterized Ball Valve Mean to You?


One of the best inherent qualities of a quarter-turn ball valve is that it goes from fully closed to fully open with very little movement required.

But when you want to use a ball valve to control flow, be it precise manual, pneumatic, or electronic control, this advantage turns into a severe shortcoming. No matter how hard you try, a standard ball valve seems to go from zero to full flow with virtually no middle ground. And because ball valves are relatively simple to actuate and position, designers have long sought a way to use them as control

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valves. But because the resulting flow rates were prone to wild fluctuation — better known as hysteresis — control was generally poor.

The Solution:

To overcome this lack of control, valve designers began experimenting with “characterized” flow paths to allow finer incremental opening of the valve as the ball was turned. Internal ball openings were introduced with all sorts of unusual cuts, from odd arrowhead shapes to irregular polygons. When used in a control situation, the results were better than a regular round hole, but still imperfect and difficult to control precisely.

The Better Solution:

Plast-O-Matic engineers sought for years to find the “perfect” shape for a control ball.  Because our product is long known as “The Engineered Ball Valve,” we were unwilling to introduce a control package that was just another average performer. Engineering determined that rather than offering just a single characterized shape, we could provide a series of angled cuts, enabling system designers to choose a more precise flow pattern over the entire range of opening. These are the angled “ZC” cuts that have been in our catalog for about a decade.

Ranging from 15° to 90° profiles, the ZC angles finally gave designers a better way to control flow, yet still have the rugged advantages and relatively low price of a ball valve. Our background in customization and the flexibility of our lean manufacturing processes enable us to offer this variety, which is unique in the plastic valve industry.

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Plasto-O-Matic provides a variety of ball options for maximum linearity.

And Now, The Ultimate Solution:

Despite the incredible success of the angle-cut ZC control balls, our engineering team continued to strive for a shape that would enable a ball valve to deliver the precise flow profile of more costly control valves. After years of fine-tuning and exhaustive testing, we’re pleased to announce that the Plast-O-Matic engineering team has finally achieved ball valve control with nearly perfect linear flow rates.

Series ZC Characterized Ball Valves

Standard Features:
  • Based on the Plast-O-Matic “Engineered” True Blue Ball Valve with dual floating seats and True-union design
  • Choice of 15°, 30°, 45°, 60°, 90° V-Balls or Linear Flow Balls
  • Sizes from 3/8″ to 4″ in PVC, CPVC, Natural Polypro and PVDF
  • Manual or Actuated
  • Electronic flow control via Plast-O-Matic Air or Electric Actuators with optional 4-20mA or 0-10 DC digital positioning
  • Manual flow control via Plast-O-Matic Metering Manual Ball Valve
Custom Features:
  • Ball design can be customized to provide virtually any flow rate
  • We use pre-tested combinations of holes and cuts to deliver precisely the type of flow your application requires
  • Custom slots or angles for atypical flow rates
  • Special valve materials available

Within the water treatment industry there is a balance between cost and accuracy. Today regulatory agencies have impacted the decision-making process as there is no longer tolerance for inaccuracy, especially with regard to the dosing and concentration of chemicals used for minimizing cryptosporidium, bacteria, mold and other contaminating organic materials. The considerations in control valve selection for sodium hypochlorite (NaOCl) and other chemicals are multifaceted with hysteresis, accuracy, throughput, chemical compatibility and reliability taken into consideration.

Plast-O-Matic’s Series ZC Characterized Ball Valves with Linear control will save you money in five important areas:

  1. The Series ZC’s new linear profile provides precise control over a longer control range which allows for accurate chemical dosing control. This means you save money on chemical usage! Precise control of chemicals eliminates “over-shooting” and dithering, often the result of poorly designed flow controls. With the Plast-O-Matic linear control ball you gain better hysteresis, accuracy, flow capacity, chemical compatibility and reliability.
  2. Minimize exposure to potential EPA fines.
  3. Initial purchase price: Thermoplastic process control valves for concentrated chemical dosing are far less expensive than their metallic counterparts. Often Hastelloy C or other exotic alloys are needed to handle concentrated chemicals, but in many applications PVC has a better rating.
  4. Thermoplastic process controls are far lighter in weight making installation quicker and less expensive.
  5. Plast-O-Matic’s industry leading three (3) year warranty provides peace of mind knowing that Plast-O-Matic stands behind their product claims.


For complete information on the Plast-O-Matic Series ZC Characterized Ball Valves please contact our knowledgeable Ryan Herco Flow Solutions sales staff at 800-848-1141.