A Techno Tanks™ bladder tank is a large, flexible container used to store many types of liquids.  When maximum capacity is reached, the bladder tank takes the form of a large pillow, hence it is also called a pillow tank. Flexible bladder tanks are made with high resistance PVC material or TPU materials and are welded with high frequency (HF) soldering techniques. The bladder walls are made of polyester with PVC induction. The materials used in bladder walls are generally UV resistant and are chosen for their chemical stability and resistance to mechanical abrasion. Additionally, they are fabricated specifically to allow the tank to stand independent of any external support.

Different compositions of bladder walls are used to store different types of liquid. For example, a particular design may be suited for hydrocarbon storage but others could be used for liquid fertilizers, chemical products, rainwater, drinking water or use water. Installation of a bladder tank is fast and simple, it requires a relatively large, flat, open surface free of rocks or other materials that might damage the walls. A berm liner is often used to minimize surface irregularities  and reduce the chance of abrasion and tank failure.