Reviewing of the coating requirements and the UL 142 leak testing steps

Reviewing of the coating requirements and the UL 142 leak testing steps, there are some safety as well as testing concerns that have come up in production.

1. Safety – we have concerns with coating in the confined storage area. The unit inner and out tanks need to be welded together for testing the interstitial space. The inside will not be coated for leak detecting. With the splash plates in the tank this creates unsafe environment for our painters. What we would like to do is cut openings in the roof to allow safer access to coating the interior surfaces. We will seal welded plates back over the openings and do a final hydro test.[Joe Klimple] approved

2. Leak testing – the steps in UL142 require 1st that we air test the tank and interstitial space as performance an leak tests (3-5 PSI). Next we hydro test both spaces (15psi). These tests are to be done uncoated. The following is our proposed modification to the procedure.

a. Prior to the testing Rio Bravo will perform die penetrant testing on all the tank welds.

b. With us coating the surfaces in the interstitial space, they will be coated when we weld the tanks together for testing.

c. 1st we will air test the spaces. If we detect any leaks, we will repair and retest.

d. 2nd we Hydro test the interstitial space, repair any leaks. Exception, we won’t hydro test the inside tank prior to coatings.[Joe Klimple] approved

Note: cutting the roof openings shouldn’t invalidate the air pressure “performance test”. All the welds where leaking and structural integrity are, won’t be affected. Leak testing will be applied again to prove the welds on the plates covering the openings.

e. Before applying coating on the plates covering the roof openings, we perform an air test. Then finish internal coatings.

f. Last we will perform final hydro test on storage and interstitial tanks.

We will hydro test all piping spools to 250 psi.

For these tank units we will use an outside company to perform the hydro tests & our painting will be inspected by a level 2 inspector from Carboline.[Joe Klimple] agreed

Best Regards,

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