Applications > SEMI FINISHED > PFA Dual Laminate Ultra High Purity Acid Tanks

PFA Dual Laminate Ultra High Purity Acid Tanks

AGRU PFA GGS sheets were selected as the liner material of an ultra high-purity tank due to its near universal chemical resistance and low leachable content

AGRU PFA sheets as liner of dual laminate tanks

Location: North Eastern Unites States of America
Project: Construction of six 3 m Ø Dual Laminate tanks
Product: more than 325 m² 2.3 mm thick (0.090 in) AGRU PFA GGS sheet
Medium: H₂SO₄, H₂O₂, K₂CO_3, HNO₃, NH_3,HF
Temperature: up to 50°C
Fabricator: Composites & Metal Products USA, North East, Maryland USA

Application

The semiconductor industry requires large volumes of ultra-high purity chemicals. Chemistries on this project include H₂SO₄ (Sulfuric Acid), H₂O₂ (Hydrogen Peroxide), K₂CO₃(Potassium Carbonate), HNO₃(Nitric Acid), NH₃ (Ammonia) and HF (Hydrofluoric Acid). The tanks are designed for ambient conditions up to 50 °C and 0.12 bar.

Solution

PFA dual laminate tanks were selected as the optimum solution utilizing the benefits of the thermoplastic PFA for chemical media contact and FRP for the structural integrity. PFA was chosen as the liner material due to its near universal chemical resistance and low leachable content that allows for handling of extremely corrosive media and maximizing production yields through minimization of contaminants which are now limited to ppb (parts per billion) and in some cases ppt (parts per trillion). In addition there is a standard and supply of PFA fittings that could be directly welded to the tank for connections other than flange nozzles.

In December 2015 the PFA sheets were delivered by AGRU to Composites and Metal Products in North East Maryland. Due to urgency the total amount was air freighted from the stock of AGRU in Austria via Philadelphia. In the following month the tanks were fabricated. Composites & Metal Products used a unique proprietary fusion welding technology for the linear and circumferential welds. These welds have no raised areas and allow for easy cleaning and drainage to minimize contamination. All welds were made in a clean room environment to ensure the purity the tanks. The project successfully finished in May 2016.

Advantages

AGRU PFA GGS proprietary glass knitted fabric backed for excellent thermoforming and superior bonding to FRP
AGRU PFA GGS has exceptional corrosion resistance to a wide variety of acids, bases and solvents
Extremely low leachable metals content allowing for the storage of ultra high purity chemicals
Thermoformed heads reducing the amount of welds necessary
Dual laminate construction eliminated metal tanks and the possibility of contamination of the UHP chemicals