Hydraulic bolt tensioners for Norsok flanges

Operations in Kıyıköy in Türkiye for the construction of the gas pipeline


Norsok Hydraulic bolt tensioners




Oil & Gas


FPT Fluid Power Technology hydraulic bolt tensioners were used to close the Norsok flanges in the Kıyıköy plant, in the province of Kırklareli, Turkey.
FPT produced the bolting tools used at the offsore pipeline landing point, in Kıyıköy, a village in the district of Vize in Kırklareli Province at northwestern Turkey. From there, the 69 km section of the first line continues to the distribution center in Lüleburgaz. The 145 km section will connect the Lüleburgaz distribution center with Ipsala on the Turkey – Greece border. Alternatively, the second line will continue from Kıyıköy to Malkoçlar on the Turkey – Bulgaria border, where it will be connected to the existing Trans-Balkan pipeline system.

FPT hydraulic tensioning systems are used to close Norsok flanges. The peculiarity of this type of flanges is a front surface not perpendicular to the axis of the studs. The perpendicularity between the front surface and the stud is achieved gradually thanks to the action of the hydraulic force applied during the tensioning phase and maintained over time once the tensioning is completed, exploiting the elasticity of the flange material itself.

FPT hydraulic bolt tensioners allow this combined roto-translation movement thanks to the presence of a special spherical joint integrated inside the tensioner which facilitates the operation while maintaining high system efficiency. The Norsok hydraulic bolt tensioners are part of the CTP-RM series characterized by a working pressure of 1500 bar and include an integrated spring return. They were supplied for the following threads: 2”1/4-8UN, 3” 1/4-8UN, 3” 1/2-8UN, 3” 3/4-8UN.
For the tensioning operations, the TTS6 model hydraulic bolt tensioners, force 2819.9 kN with a 3.1/4″-8 UN kit, 1500 bar electric hydraulic power units and a complete set of very high-pressure pipes and joints were also used. The tensioning procedure followed was on 100% and 50% bolt to tensioner ratio configuration.