How to conduct sectional pressure testing of atmospheric and vacuum distillation units using steam?

There are two purposes: ① to check whether the process is smooth； ②It is for leak testing and cleaning the internal dirt from the pipelines. Penetration pressure testing should be carried out in accordance with the operating procedures. For critical equipment, or equipment that has been overhauled, thorough inspection is required during pressure testing, especially at areas prone to problems such as joints, welds, flanges, and valves. For low-temperature phase changes and areas where heavy oil is prone to corrosion, thorough inspection is required; pressure testing can be considered successful only after confirming that there are no leaks. (2) Points to note for pressure testing after connection: ① For new equipment and process pipelines replaced during maintenance, water flushing must be carried out before performing the pressure test. A filter screen must be installed at the pump inlet during water flushing, and the control valve’s flanges should be removed to prevent debris from entering the pump and control valve. ②During the through-pressure test, the control valve uses a bypass line. ③When piercing the furnace tubes, it should be done in sections, one by one. ④For equipment such as towers and containers that have pressure testing requirements, one must not leave the site during the testing process; it is necessary to closely monitor the increase in pressure to prevent damage to the equipment due to overpressure. ⑤During pressure testing, all condensate water in the steam must be removed to prevent water hammer; severe water hammer can damage equipment and pipelines.

Therefore, segmented pressure testing is carried out to make use of steam and conserve it. During testing, pipelines and equipment with lower pressure are tested first, followed by those with higher pressure. Before testing towers and containers, the pipelines connected to them can be tested first; once these pipelines have been tested, the steam inside them can be released into the towers and containers. Next, the tower and container are press-tested. Such segmented pressure testing allows for the full utilization of steam.