This article describes 3 tests: dry spray test, submerged spray test and full operational test.
Dry spray test
This test is conducted on an empty vessel with the manways uncovered to observe the system performance.
The aim is to demonstrate the success of the three factors of the design: equal water flow from each nozzle type, correct flow ratio between inner and outer nozzles and the distribution pattern or coverage. Equal water flow from each nozzle type is to demonstrate that the manifold is correctly designed and the coverage was to check for proper spacing and orientation nozzles. This test will also prove that the pipework is clean from debris.
Submerged spray test
The aim of this test is to demonstrate the sand removal efficiency before a full operational test. A layer of sand is placed in the bottom of the vessel to a depth of 3-4 mm and the vessel is slowly filled with water, to prevent disturbing the sand, until the sand wash headers are fully submerged. The system is then activated for a prescribed period and observed. When complete any remaining sand is located and noted and the system slowly drained again to prevent disturbing the sand. Them amount of sand remaining is measured.
Full operational test
This test is identical to the submerged spray test, except that it is conducted at normal operating pressure. The vessel is pressurised with nitrogen and the system activated and the test repeated.