Sealing of our tanks

APRO Industrie supplies sealing systems (membranes, mastic seals or elastomeric seals) suitable for the various storage applications, providing an appropriate solution to each problem encountered (industry, public services etc.)

Sealing by seals (mastic or elastomeric)

In the case of sealing by a mastic seal, the metallic shell plays a structural role and simultaneously provides sealing of the tank. The steel or its coating, are then in direct contact with the stored liquid.
Sealing between the sheets is achieved using a mastic seal.
Depending on the liquid stored, the seal may be:
– mastic type (a paste seal applied in the from of a bead of sealant whose drying and hardening by polymerisation ensure the longevity of the seal)
– elastomeric type (dry seal between sheets – the seal is then achieved by appropriate and homogeneous clamping of the bolt lines).


There exist different types of mastic seals to meet various constraints: High chloride contents, temperatures beyond 65°C, solvents etc.)
The different elastomeric seals which we employ provide even greater constraint tolerances (hydrocarbons, extreme pH, very low temperatures, etc.).

Sealing by membranes (or liners)

In the case of sealing by membrane, the metallic shell plays an exclusively structural role. The metal tank is lined internally with an integral membrane which provides a total seal.
The materials employed for our membranes are selected according to the storage applications concerned. In each case, a compatibility analysis is undertaken by APRO Industrie in order to ensure the perfect suitability of the chosen materials with respect to the storage conditions involved.


Our one-piece membranes are prefabricated in the factory to the exact dimensions of the tank.
Sealing by membrane is applicable to new projects but they can also be used to line existing tanks (welded steel, concrete etc.) – including if they are damaged – to provide them with a second life or simply to extend their operation whilst saving the cost of a complete reconstruction [renovation].