When respect to the filter housing/ filter vessel, with different working conditions, the material adopted may be different, such as SS304, SS316L, etc.

When filtering some normal corrosive liquids or some solutions that need to be specially taken care of, as usual, we suggest to use SS316L for safety.

For the design of Zonel Filtech the material touch with the liquids will adopt the SS316 and some parts not touch with the liquid will adopt the SS304, when we offer this choice, some clients do not so understand, suppose we lower the quality to make the price of our SS filter houses competitive only, which is not true! So we need to do some declaration to our clients as following for reference.

When we process the stainless steel, especially the bolts, and nuts, when we fix them together, the surface between the bolt and nut will increase to quite a high temperature in a short time (especially when we are fixing them fast), which may hurt the oxidation film on the surface of the accessories, which lead the two parts to seize together.

To avoid similar problems, sometimes we will grease the stainless steel bolts and nuts, but for the stainless steel filter housing, which is not allowed because it may cause some pollution problems!

When changing the bolts and nuts with different stainless steel models it is helpful to solve this problem perfectly.