Key Points for Explosion-Resistant Retrofitting of Buildings in Petroleum and Chemical Enterprises

Key Focus Areas for Blast-Resistance Retrofit of Buildings in Petrochemical Enterprises

• Integrity of hazardous-source and building information

Enterprises involving major hazards should provide equipment/process layout and flow diagrams, building plan and elevation/section drawings, information on hazardous sources including material balance sheets, and safety assessment reports for explosion safety assessment. If the above information cannot be provided, explosion simulation analysis may be impossible or the numerical results inaccurate, making it more difficult for subsequent technical proposals to pass review by experts from the Ministry of Emergency Management and greatly reducing the actual effectiveness of the blast-resistance measures.

• Determination of retrofit zones

The determination of blast-resistance retrofit zones for buildings is based on GB/T50779-2022 "Design Standard for Blast-Resistant Petrochemical Buildings". In addition to conducting explosion safety assessments for hazardous units facing the building (blast-facing side), the blast shock wave values obtained from DNV PHAST software must be substituted into formulas to derive the blast shock wave parameters for the non-blast-facing side.

• Determination of structural blast-resistance capacity

When blast shock wave values exceed the allowable range specified in national standards, in addition to designing protective measures, the building structure itself should be checked and blast-resistant structural calculations performed using PKPM or other similar structural analysis software. If calculations determine the building structure cannot withstand the explosive loads, a blast-resistant reinforcement design must be provided to strengthen vulnerable structural members to ensure the building will not collapse or be damaged by the explosion.

• Principles for selecting blast-resistant design

According to GB/T50779-2022 "Design Standard for Blast-Resistant Petrochemical Buildings", common blast-resistant measures (aside from movable blast shelters) are mainly two types: blast-resistant coatings and blast-protective enclosures.

Blast-resistant coatings are applied by spraying and reinforcing existing interior walls to provide resistance against blast-induced displacements. The technical advantages of coatings are short construction periods, no hot work, and convenient indoor application. However, a critical drawback is the impact on production and operations, especially for existing buildings with occupied control rooms and spaces. In addition, if there are wall-mounted devices or suspended ceilings indoors, they must be removed and reinstated, which may cause equipment damage or installation difficulties during construction.

Blast-protective enclosures can be installed in suitable ways according to the exterior wall conditions, mainly classified as externally mounted, embedded, or wrapped types. Fire-resistant and blast-resistant panels are used to reinforce walls. The technical advantages of enclosures include outdoor installation with minimal impact on occupied control rooms, and avoidance of removing unreinforced interior parts and related structural components. Besides meeting fire endurance and blast-resistance requirements, enclosures should be tested for impact resistance, sound insulation, and thermal insulation performance.

Experts from the Ministry of Emergency Management need to focus on the following key points when reviewing blast-resistance retrofit technical schemes and during project acceptance: Safety assessment: Experts need to evaluate whether the proposed blast-resistance measures are sufficient to ensure the building can provide adequate protection in the event of an explosion. They will pay attention to whether any hazardous areas were omitted, whether structural weaknesses have been fully addressed, and to the effectiveness and operability of the measures.

Regulatory compliance: Experts need to verify whether the technical scheme, qualifications of relevant analysts, explosion simulation analyses, explosion mitigation effect analyses, structural calculation analyses, and test reports of blast-resistant products comply with applicable national standards and regulations. This includes petrochemical blast-resistance standards and building safety-related regulations. The feasibility of the scheme depends on its ability to meet all necessary regulatory requirements.

Construction acceptance report: Experts need to review the construction acceptance report to ensure the implementation of the blast-resistance retrofit complies with relevant standards and codes, and to review clarification services provided by the owner. This ensures effective implementation of the scheme and conformity with agreed requirements.

• Compliance of retrofit scope and construction qualifications

According to the blast-resistance retrofit practices in GB/T50779-2022 "Design Standard for Blast-Resistant Petrochemical Buildings", the retrofit scope mainly involves exterior wall blast reinforcement, interior blast spraying, installation of blast-resistant doors and windows, and chemical filtration systems. Under national construction qualification regulations, whether acting as the general contractor or a specialized subcontractor, firms should hold relevant qualifications such as waterproofing/anticorrosion/insulation engineering, building curtain wall engineering, environmental engineering professional qualifications, etc., matching the retrofit scope to bid and carry out construction so as to ensure construction quality and compliance with national requirements.

Conclusion In summary, the key focus areas for blast-resistance retrofit of buildings in petrochemical enterprises include: ensuring completeness of hazardous-source and building information, defining retrofit zones, determining the structural blast-resistance capacity of buildings, selecting appropriate blast-resistant design schemes, expert review focus during scheme validation and acceptance, and compliance of construction units.

By comprehensively considering these points, the blast safety of buildings in petrochemical enterprises can be effectively improved, potential explosion risks reduced, and compliance with national regulations and laws ensured.