THE PROBLEM
The sectional GRP sprinkler tank that serves Ashton-Under-Lyne covered market was leaking into the plant room. A tank lining solution was required to resolve the issue.
SOLUTION
Sectional GRP tanks are prone to an amount of movement when emptying and filling as a result of their modular construction. This would pose a problem for more rigid and brittle tank linings such as epoxy tank lining and glass fibre reinforced tank linings.
Taking this into account we proposed the application of Acothane DW – a flexible polyurethane tank lining.
Initially as per best practice when relining sectional GRP tanks we first checked the tightness of any bolts and tightened where necessary.
All protruding panel sealant was then cut flush prior to abrading the tank internals to raise a surface profile to ensure good adhesion of the new tank lining. All surfaces were then vacuum cleaned to ensure adhesion of the new tank lining, verified using a dust tape test.
To ensure adhesion to the roof supports which are made from thermoplastic which is difficult to adhere to these were heavily abraded and treated using Corrolastic SG – a unique material that will adhere to prepared thermoplastics.
As part of our standard quality assurance dehumidification was installed and the climatic conditions tested and recorded using Positector climatic monitoring equipment.
All panel joints were treated using a polyurethane jointing compound to provide additional sealing and also isolate these points of potential movement from the new tank lining, providing greater movement potential.
All seams and joints received an initial stripe coat of Acothane DW prior to the application of two full coats to a nominal dry film thickness of 1000 microns. As per best tank lining practice these coats were applied in contrasting colour to aid application.
As it is not possible to spark test these type of tanks to check for porosity given the non conductive substrate a thorough visual survey of the completed tank relining was undertaken and repairs undertaken where necessary.
Following full cure of the tank lining the tank was refilled and our works verified with a 10 day drop test which proved the effectiveness to the tank relining works.
