Published on:2021-11-22 17:21:21 Click:501 Author:sales@rovcable.com
Wet-mate connectors are the linchpin of a successful underwater application. Unless you identify the right subsea connectors for your project, it could be dead in the water — or, at the very least, require frequent, expensive repairs.
To prevent that, let’s review the typical options available for underwater connectors, the benefits and shortcomings of each, and what considerations should be key to your decision-making process.
Underwater connectors, also known as wet-mate connectors, subsea connectors or marine connectors, are designed to be mated or unmated in wet environments and capable of withstanding the most extreme environments, from corrosive seawater and pressure to vibration and shock.
A traditional underwater connector relies on a watertight seal. Several variations have been developed over time to achieve this, including:
A wet-mate connector is created between a female connector end and a glass-reinforced epoxy bulkhead connector through a locking sleeve as well as neoprene or polyurethane over-molding.
Rigid shell wet-mate connectors are molded into a rigid body to offer greater stability, strength, and lockability. Two connector halves are screwed together, sealing the junction with an O-ring.
A chamber is filled with oil or another dielectric fluid to isolate the contacts from water. As the ends are mated, the contact pins are wiped clean by the diaphragm in the face of the receptacle.
These pinless connectors connect magnetically without exposing any conductive parts to the outside environment.
How do you determine which type of standard wet-mate connector is best for your needs? Let’s take a deeper dive into the specs to consider for each.
The industry’s long standing underwater connectivity solutions vary in application, material, and design. A typical underwater connector often features O-rings, gasket seals or oil bladders and copper contacts.
Before settling on a product, be sure to evaluate the following key criteria.
The metal used must be strong enough to withstand its intended marine environment. Depending on a project’s needs — such as extreme corrosion resistance, tensile strength, minimal electrical conductivity, or a high melting point, 316 stainless steel, Inconel and titanium are considered three materials of choice.
316 stainless steel is a typical choice as it is well-equipped to resist corrosion after undergoing manufacturing processes that involve welding. It also withstands high-corrosion environments and boasts considerable resistance to heat.
A variation of stainless steel, Inconel is considered a superalloy due to its mechanical strength, surface stability, and corrosion resistance.
Few pure metals have more strength than titanium. It has an extremely high corrosion resistance and a tensile strength at least double that of aluminum.
From a cost perspective, stainless steel is a reasonable choice for wet-mate connectors and will stand up to the elements quite well. However, for applications that require truly exceptional corrosion and heat resistance, titanium is the preferred option.
Peak performance in the field is where it matters. Some wet-mate connectors boast guarantees of remaining operational underwater for up to 25 years along with long-term water resistance while others are considered difficult to implement in the field due to a tendency to leak or become compromised at a certain pressure rating.
As the depth of your application plummets further underwater, the equipment is subjected to increasing amounts of pressure reaching up to and often greater than 10,000 psi. This amount of force can negatively impact any number of components, increase system failures or jeopardize operations.
Typical connectors come in a range of cable assemblies, including electrical, fiber optic, or pressure-balanced oil-filled.
Wet-mate connectors are rated for an application’s specific depth and pressure. For example, a subsea connector may have a mated pressure rating up to 20,000 psi but is tested in an even more rigorous marine environment.
A long lead time generally is required as traditional wet-mate connectors take 18 weeks, or more than 4 months, from the time an order is placed until delivery (and that’s without any disruptions in the supply chain).
Researching each of these seven key criteria relative to the specifications needed for your project will help in identifying the best traditional wet-mate connectors for your application.
It’s important to note that regardless of the advancements made over the years, underwater connectors still mix electricity with water. Traditional underwater connectors attempt to exclude water from their contacts by using rubber seals, oil or moving parts.
Despite the industry’s best efforts, these wet-mate connectors are expensive, run the risk of high failure rates due to corrosion and other environmental factors and pose a potential safety risk.
