must always be positive at any point of the riser to prevent instability phenomena buckling for example this equation allows to couple the tensions in the various pipes main pipe and auxiliary lines and thus to recalculate all the thrust loads in each component of the riser these small diameter pipes are fastened individually along each riser element their ends are provided with the required seals but they include no device allowing stresses to be transmitted from one pipe to the next the simply floating pipes fit into one another thus by first approximation no high actual tension is exerted on these pipes t actual al u2248 p i u2062 s e s i if we assume that the seal diameter equals the outside diameter of the pipe these pipes carry fluids under high working pressure and therefore t eff u2062 u2062 ec u2062 u2062 t u2062 u2062 i u2062 u2062 v u2062 u2062 e a u2062 u2062 l p i p e u2062 s s u2062 u2062 e u2062 u2062 a u2062 u2062 l a u2062 u2062 l is greatly negative if the pipe is under high internal pressure thus the pipes will tend to buckle and properly spaced out clamps are required to overcome this tendency another important effect induced by the pressure applied to the peripheral lines is the increase in.