Issues regarding the management of off-spec pressure vessels

In accordance with the Regulations on Safety Supervision of Pressure Vessels, special safety assessments are required for pressure vessels that fall outside the specified categories, along with corresponding registration and supervision. Specific management requirements include: 1. Passing a safety assessment by a professional agency and registering accordingly. 2. Have reliable monitoring, management systems, and emergency response plans. 3. Conduct regular inspections and maintenance to ensure its safe use. 4. In case of any major changes or incidents, report them to the relevant departments promptly. Therefore, if you possess pressure vessels that fall outside this category, a specialized safety assessment is required, along with documentation, as well as the establishment of appropriate management and monitoring mechanisms. At the same time, if any abnormal situations or accidents are detected, they should be reported to the relevant authorities promptly to ensure personal and property safety. .

There is no need to go through any registration procedures for use. The user is responsible for the safety management of its use. It should be noted, however, that external containers are not equivalent to non-pressure vessels.

The hazard level is not very high; following the relevant industry regulations is sufficient

1. “Class outside” is a colloquial term, not an official term used in regulations; **there are naturally no rules regarding it**； 2. You can send a notification, but they won’t pay any attention to you.

There are two types of \"non-conventional\" containers I have come across. One type is very small and operates under certain pressure; it is manufactured as a pressure pipeline component, but it still falls under the category of special equipment. It is not installed alone, as it comes along with associated pipe sections and valves. For such installations, approval is required, but the application is submitted in accordance with the regulations for pressure pipeline components； Another type is atmospheric-pressure containers, which hold media that are non-toxic, non-lethal, and not flammable or explosive, such as water. Such containers do not require registration for installation, and local regulatory authorities generally do not oversee them either.

So, after submitting the notification for manufacturing as a pressure pipeline component, is registration still required?

If it is just a standalone external container, no installation notification or registration is required. For example, in our workshop we have installed filters for high-pressure air pipelines on our own; these filters are quite small and classified as external components, so no procedures are needed； If the external container is equipped with a pressure pipeline, notification and registration procedures must be carried out together with those for the pressure pipeline.

Hello, in which article of the Regulations on Safety Supervision of Pressure Vessels is it stated that special safety assessments are required for pressure vessels that fall outside the specified categories? Thank you

Regarding the management of pressure vessels other than those falling under specific categories, answers must be provided in accordance with regulations and standards such as China’s \"Special Equipment Safety Law\" and the \"Safety Technical Inspection Regulations for Fixed Pressure Vessels\" (TSG 21-2016). Here is a summary of the key points: 1. Definition of pressure vessels outside the specified categories Pressure vessels outside the specified categories refer to those that do not fall into Categories I, II, or III as defined in the \"Pressure Vessel Classification Standards\"; they are typically vessels with lower design pressures, smaller volumes, or less hazardous materials, and are not included in the management list of special equipment. Judgment criterion: Design pressure ≤ 0.1 MPa (gauge pressure) ； Volume < 30L and diameter < 150mm ； Non-flammable, non-toxic, non-corrosive media, etc. (refer to Article 1.4 exemption provisions of TSG 21-2016). 2. Is regulation needed? Outsider containers are generally not regulated as special equipment; however, they must still meet the following requirements: Self-management by enterprises: It is necessary to ensure that their design, manufacture, and use comply with relevant **standards (such as GB/T 150 “Pressure Vessels”). Safety responsibility: Enterprises must bear the safety risks themselves; in the event of an accident caused by design/manufacturing defects, they remain liable under the law. Recommendation standard: Even if it is not classified as such, it is recommended to refer to the general technical specifications in TSG 21 (such as material and welding requirements). 3. Precautions for special circumstances: Medium characteristics: If the medium inside the container is a high-risk chemical (such as hydrogen sulfide or liquid ammonia), local regulatory authorities may require registration even if the pressure/volume requirements are not met. Industry requirements: Industries such as chemicals and petroleum may impose additional requirements on non-standard containers through industry standards (such as HG/T 20580). Change risk: If the operating conditions change (such as increased pressure or a change in the medium), it may be reclassified under the supervision of special equipment. 4. Recommendations for enterprises: Design and manufacturing: Engage a qualified entity, and retain documents such as design files and material certificates. Regular inspections: Establish an internal inspection system to monitor risks such as corrosion and leaks. Regulatory updates: Pay attention to the **SAMR’s adjustments to the list of special equipment (for example, some small containers have been removed from this list in recent years). 5. Examples of common questions: Q: Do atmospheric storage tanks (such as diesel tanks) need to be managed as pressure vessels? A: If the design pressure is < 0.1 MPa and it is not flammable or explosive, it is usually not included, but it must comply with the \"Safety Standards for Atmospheric Pressure Storage Tanks\". Q: Is it necessary to submit a inspection request for laboratory small-scale reactors (25L, 0.08MPa)? A: Outside the category, but if the medium is a toxic gas, it must be managed in accordance with the Regulations on the Safety Management of Hazardous Chemicals. For specific examples or explanations of local policies, it is recommended to consult the local special equipment supervision agency or a third-party testing institution.