Certified hydrostatic pressure testing of cyclone pulp distributors, cyclone assemblies and components as well as launders is now available at the Multotec Group’s manufacturing facility in Spartan, Gauteng. Pressure vessel verification testing is also offered. “Every pressure test for pulp distributors conforming to pressure vessel standards is conducted in accordance with the world standard ASME VIII or BS EN 13445 or other applicable standard,” Faan Bornman, Product Manager, Cyclones for Multotec, stated.

The test is conducted at a pressure of 1.5 times the design pressure or to client specific requirements, where applicable. The test method is used as a screening tool to determine the integrity of the target product body and welded joint efficiencies under hydrostatic pressure to which a liquid-tight and deflection resistance is essential. Bornman states that an incompressible liquid such as water or oil is used for most tests. A combination of positive displacement pumps and safety relief valves is used to slowly increase pressure to a predetermined level for a set time. “For PED requirements a visual inspection is subsequently performed to determine whether any leakage exists or whether the pressure reduces from set pressure point. Physical deflections on the casing or shells are also measured and recorded,” he states.

Multotec Process Equipment undertakes hydrostatic pressure testing on pulp distributors manufactured in-house prior to approval for completion of the manufacturing process, including lining, coating and assembly. The testing service is also offered to external clients and can include refurbished components as well as spare parts that may have been warehoused for a time. Pulp distributors not designed to pressure vessel regulations are subjected to the MPE hydrostatic internal test procedure CTS010, a test that aligns with international standards. With all tests, a written analysis and record of all measurements are to be taken in order to demonstrate that the given vessel meets the requirements of the appropriate hydrostatic test. As an original equipment manufacturer (OEM), Multotec has the authority to provide certification of all in-house testing.

The following methodology is applied for hydrostatic testing: all seams, connections of fittings, plugs, couplings and welds made to the outside surface are visually examined for leakage. For distributor testing, if a leak is detected at any pressure level reading during the test, the pressure is immediately reduced to one-half of the pressure level reading while the leak is located. The deflection of the distributor wall, lid and under pan are measured and recorded at 25%, 50%, 75% and 100% of the pre-determined test pressure. The pressure is maintained for 15 minutes at each interval. After inspection, the vessel or system is relieved of its pressure gradually, the vents at the top of the system are opened, the liquid media is drained and the system dried to preclude excessive corrosion. Thereafter, the unit is signed off to allow further manufacturing processes to be undertaken.