In the LNG industry today, the significance of top entry valves is continually growing, driven by rising awareness of the need for these type of valves as well as design code demands, especially in cryogenic and marine applications.

Both offshore and cryogenic pipelines are greatly affected by mechanical stresses, coming either from a ship motion and vessel deflection, or from high contraction and expansion levels, caused by temperature fluctuations during the process.

Taking all these factors into account, it’s clear that the pipelines need to be exceptionally rigid, with minimal leakage points such as flanges or threaded connections.  However, enhanced rigidity and pipe integrity may be achieved only if the system components are constructed in one piece and are firmly integrated with the piping by welding or similar method to form a “one-piece” structure.

The Top Entry valve is the ultimate solution for these challenges due to its one-piece body construction – providing high integrity with the pipeline on one hand and inline serviceability on the other.

However, valve construction of this kind presents major engineering challenges, since all its inner parts have to be placed and assembled via a single and relatively narrow top opening.

However, valve construction of this kind presents major engineering challenges, since all its inner parts have to be placed and assembled via a single and relatively narrow top opening.