A rèir a radius of curvataure, faodar a roinn ann an olcow fada radius agus elbow goirid radius. Tha Radius fada Elbow a 'ciallachadh gu bheil radius curvataure co-ionann ri 1.5 uiread de thruamaiche a-muigh na pìoba, is e sin, R = 1.5d. Tha Radius Goirid Elbow a 'ciallachadh gu bheil an radius curvataure co-ionann ri trast-thomhas a-muigh na pìoba, is e sin, R = 1.0d.