Protective envelope for an apparatus fitted on a piping conduit.
1. A protective box for apparatus mounted on piping, the box comprising two shells (1, 2) of thermally insulating material having their edges provided with mutual assembly means (9, 12) enabling the shells to be assembled together to form a closed housing (3) for the apparatus, the box being characterized in that the shells are flexible and have clamping means in appropriate locations for clamping around the piping, said clamping means being constituted by complementary collar elements (15, 16).