3D Technical Design (3DTD) were appointed by CPV to undertake the expansion and stress analysis for the new above-ground pipe route design for the Royal Air Force (RAF) Fylingdales base. The analysis was carried out on the DN125/225 main spine with DN50/125 branches, in accordance with BS EN13480 for above-ground pipe systems by using project class B with 250 load cycles and a design temperature of 110 °C.
Firstly, the minimum required length for the vertical directional changes was calculated, enabling the designer to assess the route design and make required changes where the minimum length was not maintained. Our specialists determined that the minimum length of each vertical section should be 1000 mm as shown in the typical service duct entry detail, to absorb thermal expansion.
During the assessment, it was found that the distance between the main spine and the building entry point, which acts as an anchor, was insufficient. The external straight section of the DN 50/125 branch was not long enough to absorb the displacement of the main spine resulting from thermal expansion. To rectify the issue, the two DN 125/225 pipes had to be moved further away from the wall to achieve a minimum required distance of 900 mm. Following the above amendments to the sisKMR model, the DH pipework passed the stress and expansions analysis, and all stress values were below the maximum allowable limits.