Pset_PipeFittingOccurrence Pipe segment occurrence attributes attached to an instance of IfcPipeSegment. IfcPipeFitting IfcPipeFitting InteriorRoughnessCoefficient The interior roughness coefficient of the pipe segment. Interior Roughness Coefficient 内部粗度係数 配管部の内部粗度係数 Color The color of the pipe segment. Note: This is typically used only for plastic pipe segments. However, it may be used for any pipe segments with a painted surface which is not otherwise specified as a covering. Color 色 配管部の内部粗度係数　記：プラスチック配管にのみ使われる。保護のためではない塗装された表面を持つ配管にも使われる。