Abstract: There is necessary to carry out ball through pipeline before commissioning to cleaning remains in construction in pipeline. For small diameter pipeline it is more difficult than for large diameter pipeline. There are three fields of workings: ensurance of gas quantities, control of ball velocity, auditory - checking points in ball through operation. When the ball is blocked first is to analyses and work out the prelimirary-point blocking, then to prove the point by heating methods, at last to make hole for finding ball and blockage solution. The paper made an introduction of ball through and process of bockage solution for small-diameter pipeline, and explanation of blockage in horizontal pipeline.