Tank Farm: Storage & treatment of water during Hydro Testing

Challenge:
Our customer needed to perform a complete safety and quality inspection of several large storage tanks within it’s tank terminal. After a comprehensive review and maintenance programme, the integrity of the tanks had to be checked and approved by a Hydro test. Using fresh water wasn’t the preferred option from an environmental and financial point of view. In close collaboration with the customer and local authorities, we designed a solution using a limited amount  of surface water and acceptable level of discharge into the sewer. A part of the operation had to take place in an ATEX-zone. 

Solution: 
We engineered an integrated solution that consisted of four steps using water from the river.  

1. Intake of surface water by a 6” Diesel Centrifugal Pump (outside ATEX-zone). Using a strainer in the suction line and two parallel 8-Bag Filter Systems (duty-standby) we ensured a visible clean filling of the first tank for the hydro test. 
2. After an approved test, the water from the first tank was transferred by two 6“ Electric ATEX Pumps (duty-standby) to the second tank. By using a duty-standby pump configuration, pressure-switches and multiple hose ancillaries we created a solution with a focus on flexibility, automation and safety.
3. The third tank was filled with water from the second tank using the same process and equipment as used in phase 2 of the project. 
4. After the third successful hydro test, the water from Tank 3 was transferred by the same two 6“ Electric ATEX Pumps towards two 8-Bag Filter Systems placed in series.The first filter system was equipped with 100 micron filter bags, the second with special oil absorption filter bags. With this combination of transfer and treatment equipment water was purged back into the surface water - course in accordance with the maximum permitted flows and required removal of suspended solids and hydrocarbons.