From subsea to life on land - gasket technology follows Darwinism

Typically, a gasket fails to capture much attention, because it is thought of as a small detail from a macro perspective in piping infrastructure design. Serving as a meeting point between two pipes, flanges are identified as a risk in the construction or update of any production facility. However, through the usage of spiral-wound and kammprofile technologies, most production facilities currently anticipate or accept certain levels of leakage as normal. This approach often has gaskets being treated as a consumable.

Both of these technologies offer similar lifespans and an equal amount of required maintenance while in operation. As a result, gaskets are selected as a last detail for the final facility design, with the overall emphasis being placed on gasket cost. The most effective gasket sealing technology plays a much larger role in daily operations beyond containing leaks. When either of these sealing technologies are utilized, a true gas-tight seal is never truly obtained. This leads to the possibility of leakage points which being created, posing various risks such as;

The first differentiating characteristic is the metal-to-metal design. A metal gasket offers far more flexibility in practical applications. Utilizing metal allows for a stronger seal which is more resistant to warping, however this gasket technology is not only produced in one metal material. Each gasket is produced from the metal material which matches the material of the joining flanges. This is done for multiple reasons, the first is for maintaining sealing strength through internal or external environmental temperature changes of the pipe.

When metal is subjected to temperature changes it expands or contracts. These circumstances then require a gasket to both expand or contract along with the flange. Since different metal materials react differently to temperature change, producing gaskets from a matching metal material is required. This enables the gasket and flange to be matched in the rate of expansion or contraction, while maintaining maximum sealing strength.

Another reason for the metal construction is that it enables for an entirely different level of sealing strength to be achieved. The specially engineered metal rings incorporated into the gasket design adapts to the surface of the flange, creating a smarter seal. Under torqued pressure, the metal rings deform and adapt to the exact landscape of the flange surface, resulting in a sealing strength which exceeds the classification of gas-tight sealing strengths (equal to 10-08 mbar l/s). Interestingly, this type of sealing strength is achieved and maintained without causing any damage or deformation to the flange.

The quality and strength of the seal was confirmed through helium tests conducted by DNV GL. Helium was used in the test because of the inherent difficulty in sealing against leaks. Leaks occur easier with Helium because the molecules are smaller than oxygen molecules, making it harder to contain in a given environment. A common example of helium's propensity to escape can easily be observed with an ordinary birthday balloon over the time period of a few days. Regardless of whether the balloon is made of rubber or plastic, the helium molecules are able to pass through the retaining material unlike oxygen, which has larger molecules, making it more containable.

The test revealed that even with surface scratches as deep as 0.3 mm, spanning across the entire raised face surface of the flange remained completely gas-tight. A technological benefit such as this presents users with the ability of prolonging the lifespan of their current piping infrastructure. This can also be applied to flanges which may have previous damage equal to or less than 0.3mm in depth.

Naturally one of the largest threats of any vessel, operating at sea is fire. The danger and destructive power are more fiercely fought than any other threat. However, this presents one of the key safety benefits, which the DeltaV-Seal technology has brought to on-shore operations. The significant sealing pressure combined with its machined, metal construction enables the gasket to be fire and blowout proof. In tests conducted by German based AMTEC (Advanced Measurement Messtechnischer Service GmbH) the DeltaV-Seal showed amazing resilience against the threat of being compromised by direct flame or scorching temperatures.

The results of various tests showed that even after being directly exposed to flames for 30 minutes, the gasket withstood temperatures in excess 650° Celsius (1202° F) at 40 bar of pressure. This enabled the gasket to earn the API 6FB fire test approval. The API 6FB approval is an integral benefit to have for both off-shore and on-shore operations which involve engineers dealing with corrosion damaged flange faces or in challenging environments, such as highly flammable hydrocarbon containing systems. The same test results also showed that after 30 minutes of direct exposure, the gasket released only 1% of the allowed amount.