Call for Comments on Methods for Assessing the Aging of Chemical Process Units

To scientifically and systematically identify, assess, and manage the risks associated with aging of process units and equipment in chemical enterprises, and to establish a long-term mechanism for safety risk control, the First Division of Hazardous Chemicals Supervision under the Ministry of Emergency Management recently organized the drafting of the “Methodology for Assessing Aging of Chemical Process Units (Draft for Public Comment)” (hereinafter referred to as the “Assessment Methodology”), which is now being made available to the public for comment.

According to available information, the “Assessment Method” applies to the installations and equipment of chemical enterprises that produce hazardous chemicals or use hazardous chemicals in their production processes. Other chemical enterprises, as well as hazardous‑chemical operating enterprises (with storage facilities), may refer to this method when conducting aging assessments of their installations and equipment.

The “Assessment Methodology” notes that China’s chemical industry entered a phase of rapid development in the 1980s. As a result, some chemical facilities and equipment constructed in the previous century have been in operation for 30 or even more than 40 years, giving rise to issues such as outdated design and construction standards, low manufacturing quality, corrosion‑induced wall thinning after prolonged service, and declining safety‑assurance capabilities. Consequently, the cumulative safety risks associated with aging chemical installations have reached a critical juncture, entering a period of concentrated exposure.

The “Assessment Method” identifies the factors that influence the aging of chemical‑process equipment, which primarily include: the service life of critical equipment; the number of unplanned shutdowns; the status of equipment defects or failures; the mechanisms and severity of aging; the level of equipment integrity management; the effectiveness of inspection and testing strategies and their results; the energy efficiency and operating condition of rotating equipment; the effectiveness of corrosion protection; the degree of stable process operation; and the aging of instrumentation and control equipment—totaling ten factors.

An official from the First Division of Hazardous Chemicals Supervision at the Ministry of Emergency Management pointed out that, in China, many aging facilities have undergone multiple rounds of renovation, with numerous pieces of equipment and pipelines replaced during these upgrades. As a result, their actual service life may be far shorter than the total operating time of the facility. In a survey conducted by the Ministry, 20 units at a particular enterprise—each in service for more than 20 years—were examined, encompassing a total of 1,968 pressure vessels. Among these, 1,251 pressure vessels had been in service for over 20 years, accounting for 63.57%. Of these, 216 were rated as Safety Condition Level 1 (10.98%), 1,557 as Level 2 (79.12%), and only 195 as Level 3 (9.91%). Similar patterns are observed across many other types of equipment: nominally old but in good operational condition.

In response to the aforementioned issues—particularly the lack in China of a standardized aging‑management framework and comprehensive assessment methodologies—there is an urgent need to leverage aging assessments to establish long‑term, robust mechanisms for managing aging throughout the lifecycle of equipment. This will help standardize the evaluation of the degree of obsolescence in chemical‑process units and enable scientifically informed decisions regarding their retirement or decommissioning, thereby addressing the limitations of relying solely on service life as the basis for such decisions and providing a compliant pathway for equipment that has exceeded its design life yet remains safe to operate.

“Currently, China lacks standardized guidelines for assessing the aging of chemical‑process equipment. The establishment of this standard can swiftly facilitate the development of a long‑term mechanism for managing and controlling equipment aging, enabling a systematic and sustained approach to effectively address the safety challenges posed by aging assets,” said the official. Following the release of the “Assessment Method,” chemical enterprises are required to tailor their practices to their specific circumstances, refine relevant management systems, formulate and implement aging‑assessment plans, and adopt a recommended transition period of six months.

Source: China Chemical Industry News