Abstract: The implementation evaluation of small flow pipeline vibration damping transformation plan has been done for RIS system low pressure safety injection pump（referred to as LHSI pump） in a nuclear power plant. Combined CFD numerical calculation with simulation test circuit verification, the evaluation method of the damping effect has been adopted. Vibration limit value calculations are performed according to ASME 0M3. Pipeline stress check, hanger strength and the stiffness check of support have been completed using specialized pipeline software named syspipe. All the numerical results demonstrated that the proposed scheme is effective and feasible, and the scheme can be carried out by specific implementation.