Housing of a fluid energy machine

1. A housing of a fluid energy machine, which extends along a longitudinal axis, comprising:

a housing casing, which extends axially,

a housing cover for closing a housing opening at the axial end face of the housing casing,

an annular insert, which extends in a circumferential direction in the housing and bears against the housing casing and against the housing cover,

a first seal between the housing cover and the housing casing,

a second seal, between the housing casing and the annular insert, and

a third seal between the housing cover and the annular insert,

a sealed intermediate space, which is sealed by the first seal, the second seal and the third seal and is delimited by the housing casing, the housing cover and the annular insert,

wherein the sealed intermediate space is connected to a monitoring line, which connects the sealed intermediate space to a monitoring unit, which sends a signal to a controller if a process fluid enters the sealed intermediate space from an interior of the housing.

2. The housing as claimed in claim 1 ,

wherein the housing cover comprises a first circumferential groove, in which the first seal is arranged, and

wherein the housing cover comprises a third circumferential groove, in which the third seal is arranged.

3. The housing as claimed in claim 2 ,

wherein the annular insert comprises a second circumferential groove, in which the second seal is arranged.

4. The housing as claimed in claim 1 ,

wherein the housing comprises a barrel volute housing, and

wherein the annular insert comprises a spiral insert of a turbo fluid energy machine.