Why the iron pressure tank does not get rusty and pollute the water inside the tank? ｜Aquasky

PUMPLUS is a maintaining free diaphragm-type pressure tank. Diaphragm pressure tanks have two chambers: one for air, and one for water. They’re separated by a rubber diaphragm that’s permanently bonded to the inside of the tank, which rises and falls with the water level. 

As water is pumped into the lower section, the diaphragm pushes up into the air chamber which triggers a switch that shuts off the pump. 

While this is an efficient system, it does have its drawbacks. One is having the diaphragm come loose from the inside of the tank and letting water flow into the upper chamber. If this happens, you’ll need to replace the tank. The other problem is having the diaphragm fold over itself and causing a false reading which can lead to premature pump burn-out and the tank being ruined.

The water stays in a water chamber. There are two types of structure of water chamber in the market to avoid the water direct contact with the steel chamber. One is using a powder coating to create a layer of water protection which is normally used in Italy made tanks. Another one is using a food-grade PP to make a liner. This liner is made the same as the tank shell. The liner is using the steel tank shell as a pressure holder. The water is stored in the room between the PP liner and the rubber diaphragm.

PP liner design is preferred as a high-grade structure. The powder coating on the steel shell is a much cheaper way of making the waterproof layer. However, the layer made by coating may have chemicals dissolve out and get into the water. On the other hand, the layer may crack by a long time of Hydraulic pressure and create rust and damage to the steel shell.

The PUMPLUS Pressure tank is using the food-grade PP liner and premium butyl rubber to build the water zoom. Protect your water and no maintains is needed.