[en] Some peculiarities of radiographic testing of welded joints of steel high-pressure rolled vessels are considered. It is shown that high sensitivity and the most effectivity of the testing is achieved due to the application of 25 MeV betatron as a radiation source to test products up to 300 mm thick, and of 35 MeV betatron to test products with the thickness from 300 to 450 mm. Recommendations on planning of a betatron laboratory are given. Studies were made to determine the ability of radiographic method to identificate natural defects when testing vessels. For this purpose previously determined were: spatial-angular distribution of the betatron bremsstrahlung radiation, energy dependence of the intensity of bremsstrahlung radiation, optimum thickness of lead shields at various radiation energies. It is established that the above method of testing makes it possible to separate defects of 2-5 mm size such as pores slag inclusions and faulty fusions