Power Piping Design

FEM calculation and code check

BWE offers design, manufacture and supply of metallic industrial piping including valves and fittings - mainly for power plants.

The total design of a power plant includes design and code check of the power piping conducting water or steam between the individual parts of the boiler and from the boiler to the turbine.

Thermal expansion

As the boiler and the pipes are exposed to thermal loading, the piping system will be subject to deflection caused by the thermal expansion. These deflections cause strain cycling of the material, which must be kept at an appropriate level to avoid initiating fatigue cracks in the piping material. A measure to decrease the cyclic strain level is building in a horseshoe loop, lyre loop, expansion loop or in other ways design the layout of the system with a view to increasing the flexibility of the system.

Pipe Support

In sections with small displacements, the pipe support can be designed as stiff hangers. Where considerable vertical displacements occur it will be necessary to insert spring hangers or even constant load hangers. The spring constants of these hangers, preferably delivered from LISEGA, are optimised in connection with the calculation of the flexibility of the whole piping system.

The calculations are executed using the internationally recognized piping calculation program ROHR2 supplied by SIGMA.

Code checking is performed according to EN13480, ASMEB31.1 or FDBR.

Materials

BWE makes an effort to select the materials for the piping system which match the demands to corrosion resistance, creep rupture strength as well as flexibility. For USC-boilers these demands often lead to application of the newly developed materials (P91, P92 etc.) as an optimum solution in both technical and economical terms. In the lower temperature range the WB36, 15CrMoV510 or P23 could offer the most profitable solution.