Combined-type bilayer isolating sleeve for magnetic pump

The utility model belongs to the field of magnetic pump isolating seal, and particularly relates to a combined-type bilayer isolating sleeve for a magnetic pump. The combined-type bilayer isolating sleeve comprises an inner-layer metal sleeve, an outer-layer nonmetal sleeve, a pressure transmitter and a vacuumizing valve, and each part is convenient for on-site replacement and maintenance. The inner-layer metal sleeve and the outer-layer nonmetal sleeve are independently sealed and fastened through bolts, and an annular cavity is formed between the inner-layer metal sleeve and the outer-layer nonmetal sleeve and communicated with a pressure tapping hole in an isolating sleeve flange. A gap between the inner-layer metal sleeve and the outer-layer nonmetal sleeve is 0.2-0.5mm, and pressure of gas in the gap during normal working is from -5kpa to -20kpa. The combined-type bilayer isolating sleeve is simple in structure; whether the inner-layer metal sleeve or the outer-layer nonmetal sleeve of the isolating sleeve is worn through or not can be detected by only utilizing the pressure transmitter on the isolating sleeve flange, and quick alarming can be realized for the convenience of a user to take measures as soon as possible so as to avoid leakage accidents.