I am putting together a spec for AWWA D100 Firewater tank for a job in PA. The owner is looking into insulating the tank for freeze protection and to cut down on heating cost. But per NFPA 25, section 220.127.116.11, "Exterior painted, coated, or insulated surfaces of a tank and supporting structure, where provided, shall be inspected annually for signs of degradation".
Can anyone you please advise on how to comply with this requirement, being that the tank is insulated?
is this a 100% inspection of the tank exterior or spot inspection, same like API 653 section 6.3.2?
if 100%, how to comply with this code requirement with regard to insulated CS tank?