Technical Article

Dairyland Decouplers vs. Competing Technologies

One Solid Choice: Decouplers vs. Competing Technologies

As a corrosion professional, your ideal applications keep your personnel safe and your system running efficiently. As an installer, you want tech that is easy to install and is maintenance-free. No matter your position, we know you are looking for solutions that address your multiple needs: 

  • Addressing CP isolation issues
  • Mitigating steady-state induced AC current
  • Tackling safety grounding issues for things like AC faults or lightning

Not only do you want a device that can handle all of these needs, you also need a product you can trust to perform reliably.

Alternative Technologies

There are several devices on the market that attempt to resolve one or more of these concerns. However, maintenance needs, limited lifespans, and safety concerns all come attached to their price tags. Dairyland decouplers offer a solution to all of your CP isolation and over-voltage protection needs and have a proven track record for their rugged performance. Below, we outline briefly how each technology functions and then compare key qualities between the 3 technologies. 

Liquid-filled polarization cells are designed to block DC current from a cathodic protection system, in order to maintain the effectiveness of the CP system. These devices are made of stainless steel or nickel plates that are immersed in potassium hydroxide electrolyte. When a low DC current is present, the device polarizes the plates and limits the flow. They pass higher voltage DC, steady-state AC, AC faults and lightning current. Regular maintenance of the fluid level is required, especially under conditions where AC steady-state induced current is present to maintain the product’s performance characteristics. This technology is being steadily replaced by more reliable solid-state decoupling devices. 

Spark gap arresters are made of two electrodes separated by a gap, usually filled with air. When the voltage between the electrodes exceeds the ability of the air gap to isolate, the current will arc over and flow through the device. They are made to respond to lightning, but usually require several hundreds or thousands of volts to arc. Spark gap devices cannot carry typical AC fault levels for any significant length of time and are not suitable for use to provide AC voltage mitigation.

Solid-state decouplers use electronic switching components to isolate DC current from cathodic protection systems from grounding paths. They also simultaneously provide a safe grounding path for AC fault and lightning events. Normally, the switch remains open and is able to isolate DC current to a certain threshold, while allowing any steady-state AC to flow to ground that may be induced from power lines. During a lightning or AC fault event, the switch closes and allows the high current to pass to ground. Then the decoupler opens the switch again to return to normal DC isolation mode, an operation that can be repeated virtually indefinitely.

decoupler comparison

Other Solid-State Decouplers

Since our beginning in 1983, Dairyland has become the premier manufacturer of solid-state decoupling devices around the world. More recently there have been solid-state decouplers introduced by other parties in various countries around the world. While these products have attempted to mimic Dairyland designs, no other product to date has been able to match Dairyland’s performance, or reliability.

Always Rugged.

  • Wide variety of performance ratings and environmental ratings
  • Unique, proven construction assures maintenance-free operation
  • Assured fail-safe design, independently tested
  • Proprietary manufacturing methods that assure corrosion resistance, high AC fault capability, and low leakage current
  • Extenive third party certifications for proven performance

Always Reliable.

  • Impeccable performance record featuring a .001% failure rate across product lines
  • Experienced application and technical support
  • Fast, reliable customer service
  • Proven, tested manufacturing processes ensuring consistent product quality
  • ISO 9001:2015 certified company ensures quality processes from start to finish

With their rugged construction, versatile design and proven reliability, Dairyland’s solid-state decouplers are the smart choice over other DC isolation devices available. Long-term, you will save maintenance labor and material costs by installing Dairyland devices, while mitigating risk to your equipment and personnel.

In addition to manufacturing industry-leading products, we pride ourselves on providing reliable technical support. If we can be of assistance in your applications, please contact our technical support team.

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