hi everyone,
my company has requested two new APHs with glass or coated tubes at the cold bundle. all proposed offers are coated tubes but i read that coated tubes are not recommended and have the same problem as the cast iron can anyone mention the disadvantage of coated tube and problems that could occur such as corrosion and coating spell with references???
also i have other issue about monitoring the minimum metal temperature or the coldest part of APH as all offers supply two skin temp. at the outlet of last metal bundle before the coated tubes bundle which means i cannot monitor the wall temperature of the coated tube is that correct or i should place the skin at the end of coated tubes bundle ??? can anyone explain to me that/
thanks in advance