Tracking of the rate of corrosion of a metal conduit traversed by a corrosive fluid
A method of tracking the rate of corrosion of a metal conduit traversed by a corrosive fluid, in which is provided a device arranged so as to form, when said device is installed on a wall of the metal conduit, a chamber able to receive gaseous hydrogen issuing by permeation across said wall of said conduit, the method comprising: (i) a step of treatment to eliminate a metallic species from the chamber, (ii) a step of measuring a quantity of hydrogen received in the chamber, with a view to estimating the rate of corrosion of the metal conduit.
1. A method of tracking the rate of corrosion of a metal pipe conveying a corrosive fluid,
in which, a device installed on a wall of said metal pipe forms a chamber that is able to receive gaseous hydrogen resulting from permeation through said wall of said metal pipe,
the method comprising:
(i) a treatment step for removing, from the chamber, a metallic species that could be reduced by the gaseous hydrogen by scavenging the interior of said chamber with a stream comprising gaseous hydrogen, and wherein at least the chamber wall formed by said pipe is treated on its entire surface during the treatment step, and
(ii) a step of measuring a quantity of hydrogen received in the chamber, with a view to estimating the rate of corrosion of the metal pipe.
2. The method as claimed in claim 1 , further comprising:
a step of scavenging the interior of the chamber with an inert carrier gas following the treatment step, and
a step of measuring the quantity of hydrogen contained in the carrier gas following the scavenging step.
3. The method as claimed in claim 2 , in which the inert carrier gas additionally contains hydrogen.
4. The method as claimed in claim 3 , in which the hydrogen concentration in the inert carrier gas is between 10 and 10000 ppm.
5. The method as claimed in claim 1 , in which the step of measuring said quantity of hydrogen received in the chamber is carried out by means of a detector comprising a nickel-palladium membrane.
6. The method as claimed in claim 1 , in which the treatment step is performed by scouring the internal surfaces of at least one portion of the walls of the chamber.
7. The method as claimed in claim 1 , further comprising a step of welding the device onto the wall of the metal pipe so as to hermetically seal the cavity.
8. The method as claimed in claim 1 , in which the treatment step is carried out prior to installation of the device on the wall of the metal pipe.