15CrMoG steel pipe hydrogen purification principle is at 300-500 ℃, the hydrogen to be purified through the side of the steel pipe 15CrMoG when hydrogen is adsorbed on 15CrMoG steel wall, due to the lack of two Pd 4d electron shell electrons, it can generate an unstable chemical bonds with hydrogen (palladium and hydrogen such reaction is reversible), under the action of palladium, hydrogen is ionized proton radius of 1.5 × 1015m, while palladium lattice constant of 3.88 × 10-10m (20 ℃ when), it can be 15CrMoG steel pipe, but also combines the role of protons and electrons of palladium and re-formation of hydrogen molecules from the other side 15CrMoG steel pipe to escape. In 15CrMoG steel pipe surface, the gas dissociation is not impervious, it can be used to obtain high purity 15CrMoG steel pipe.