Definition - What does Groundbed mean?
A groundbed is an electrode array that is installed beneath the ground to give off a path with low resistance to ground. It is a vital component of the grounding system. In terms of cathodic protection, this groundbed refers to the anodes' arrangement in water or ground, which provides a way for protective currents out of anodes into an electrolyte.
The application of a groundbed serves the purpose of covering cathodic protection. Different groundbeds have been successfully used to provide cathodic protection to surface equipment as well as pipelines to prevent the occurrence of corrosion and any form of damage.
Corrosionpedia explains Groundbed
Almost all types of steel tanks, pipelines and equipment have anodes, typically magnesium. These anodes are eventually reduced or become damaged by corrosion. As anodes undergo corrosion, they produce small electricity currents that protect steel from the harmful effects of corrosion. Due to this, magnesium anodes are also referred to as sacrificial anodes. This highly effective type of protection is known as cathodic protection. The expected lifespan of anodes is up to three decades. When its life ends, no more protection is expected for steel tanks, pipelines and other structures.
The options are to replace the entire structure, which can be very expensive, or bury more anodes close to these structures. Although the second option has a lower initial expense than the first, it is pricier in the long run. The best and most cost effective option is to make use of a groundbed current protection system to replace the magnesium. These anodes should be buried deep in the ground a certain distance away from the structure it protects.
A groundbed cathodic protection system is a low-cost and highly effective option, since various components like tanks, pipes, fuel pumps, wirings and others need not be interrupted. All that is needed is a deep hole for the anodes. It is not required to put anodes close to the structure; the hole can be as far as 15 feet as it can produce current that can reach the structure evenly. Using a groundbed to provide cathodic protection simultaneously to structures can be very beneficial, since it is the kind of protection that cannot be achieved with anodes alone.