Circular No. 49/2015/TT-BLDTBXH promulgates National Technical Regulations on occupational safety for fixed metal gas pipeline systems.

CIRCULAR

Issuing National Technical Regulations on Occupational Safety

for Fixed Metal Gas Pipeline Systemsi

_____________________ 

Pursuant to Decree No. 106/2012/NĐ-CP dated December 20, 2012 of the Government stipulating the functions, tasks, powers, and organizational structure of the Ministry of Labor - Invalids and Social Affairs;

Based on Decree No. 132/2008/NĐ-CP dated December 31, 2008 of the Government detailing implementation of certain provisions

Pursuant to Decree No. 132/2008/NĐ-CP dated December 31, 2008 of the Government detailing implementation of certain provisions of the Product Quality Law;

At the proposal of the Director of the Occupational Safety and Health Inspectorate;

The Minister of Labor - Invalids and Social Affairs issues this Circular prescribing the National Technical Regulation on Occupational Safety for Fixed Metal Gas Pipeline Systems.

Article 1. Attached herewith is the National Technical Regulation on Occupational Safety for Fixed Metal Gas Pipeline Systems.

Code: QCVN 22:2015/BLDTBXH.

Article 2. This Circular takes effect from January 25, 2016.

Article 3. Ministries, ministerial-level agencies, government agencies, provincial People's Committees under central cities, and related organizations and individuals shall be responsible for implementation.

QCVN 22: 2015/BLDTBXH

NATIONAL TECHNICAL REGULATION ON OCCUPATIONAL SAFETY FOR FIXED METAL GAS PIPELINE SYSTEMS

National technical regulation on safe work of gas transmission piping

Foreword

QCVN 22: 2015/BLDTBXH - National technical regulation on occupational safety for fixed metal gas pipeline systems compiled by the Department of Occupational Safety and Health, issued pursuant to Circular No. 49/2015/TT-BLDTBXH dated December 8, 2015, after receiving comments from the Ministry of Science and Technology. NATIONAL TECHNICAL REGULATION ON OCCUPATIONAL SAFETY FOR FIXED METAL GAS PIPELINE SYSTEMS National technical regulation on safe work of gas transmission piping

Issued by the Ministry of Labor - Invalids and Social Affairs pursuant to Circular No. 49/2015/TT-BLDTBXH dated December 8, 2015, following the review comments of the Ministry of Science and Technology. NATIONAL TECHNICAL REGULATION ON SAFE WORK PRACTICES FOR FIXED METAL PIPE GAS DISTRIBUTION SYSTEMS National technical regulation on safe work for fixed metal pipe gas distribution systems

1. General Provisions

1. Scope of Application

1.1. This standard specifies requirements for design, manufacture, installation, inspection, and testing of fixed metal pipelines used for natural gas transportation.

1.2. This standard also specifies requirements for operational safety and maintenance of fixed metal gas pipelines.

1.3. This standard does not apply to:

1.3.1. Design and production of pressure vessels as specified in QCVN 01:2008/BLDTBXH.

1.3.2. Fixed metal gas pipelines with metal temperatures above 232°C or below -28°C.

1.3.3. Pipelines within natural gas extraction plants and oil refineries, and pipelines of gas processing plants.

1.3.4. Pipelines from offshore gas wells.

1.3.5. Design and production of heat exchangers.

1.3.6. Natural gas liquid pipeline systems.

1.3.7. Pipeline systems transporting liquefied petroleum gases.

1.2. Applicability of this Standard applies to:

1.2.1. Organizations and individuals producing, importing, circulating, installing, and using fixed metal gas pipelines.

1.2.2. Other relevant agencies and organizations and individuals.

1.3. Definitions:

1.3.1. Pipeline system: includes all pipelines and other components installed together with the pipelines.

1.3.2. Maintenance: activities such as inspecting the pipeline system, repairing corrosion, welding repairs, and replacing damaged parts.

1.3.3. Operation: performing the function of conveying natural gas according to the manufacturer's instructions within the scope of compliance with management regulations and current regulations.

1.3.4. Operating entity: the entity responsible for operating the gas pipeline system.

1.3.5. Pipeline: all components through which natural gas is conveyed, including pipes, valves, flanges, gaskets...

1.3.6. Shut-off valve: a valve installed to stop or block the flow of gas in a pipeline.

1.3.7. Check valve: a valve designed to allow gas flow in one direction and automatically close to prevent reverse flow.

1.3.8. Relief valve: a hydraulic device used to regulate pressure in pipelines or storage tanks. A relief valve belongs to the category of inlet pressure regulating devices.

1.3.9. Nominal pipe diameter: the designated or manufactured diameter of the pipeline.

1.3.10. Preheating before welding: the process of increasing the temperature of the heat-affected zone during welding to reduce material hardness and avoid brittle fractures caused by material brittleness.

1.3.11. Stress: a quantity indicating the degree of force applied per unit area (N/m2).

1.3.12. Cathodic protection: polarizing a metal surface subject to corrosion to reduce the rate of corrosion.

1.3.13. In addition to the terms mentioned above, this standard also uses terms defined in the American Standard ASME B31.8-2007 - Gas Transmission and Distribution Piping Systems.

2. Technical Provisions

2.1. General Technical Requirements: Fixed metal gas pipeline systems within the scope of application as specified in Section 1.1 must meet the minimum technical requirements as prescribed in the American Standard ASME B31.8-2007.

2.2. Specific Provisions

2.2.1. Welding Process Requirements: Before conducting pipeline welding, the composition of the pipeline or related equipment must establish a complete welding technology process, clearly stating the applicable standards, procedures, and requirements that the welding operator and welder must have the necessary capabilities to meet the welding process.

2.2.1.1. Preheating Requirements Before Welding: - Carbon steels with carbon content exceeding 0.32% or carbon content (C + ¼ Mn) exceeding 0.65% must be preheated before welding. - For low-carbon steels with carbon content less than 0.32%, if the welding procedure requires chemical composition, metal temperature, ambient temperature, thickness of raw materials, or characteristics of the joint geometry requiring preheating, it must be carried out accordingly. - When multiple welding materials with different preheating temperatures are used, the higher preheating temperature requirement applies. - Preheating can be performed by any suitable method but must meet the minimum preheating temperature specified in the welding process.

2.2.1.2. Stress Relief Requirements:

a) Cases requiring stress relief: - Welds on carbon steel with carbon content exceeding 0.32% must be stress relieved. - Welds on carbon steel with carbon content less than 0.32%, but which have been cooled rapidly due to other factors, also require stress relief. - Welds on carbon steel with nominal wall thickness exceeding 3.2 cm. In cases where welding components of different pipe thicknesses and made from the same material, stress relief must be applied: + For the thicker component. + The thickness of the pipe section or joint in cases involving branch connections, sliding flanges, or welded hole joints. - When any material of the weld requires mandatory stress relief.

b) Stress relief temperature: - Stress relief must be carried out at a temperature equal to or higher than 600°C for carbon steel and equal to or higher than 650°C for alloy steel. - In cases where stress relief is required for joints between multiple components with different stress relief temperature requirements, the higher requirement shall apply. - Gradual heating to the specified temperature and maintaining it for a certain period of time is required. This time is calculated based on a minimum of 1 hour for each 2.5 cm of wall thickness, but even if the wall thickness is very small, it cannot be less than 30 minutes. After that, cooling must be done gradually.

2. 2.1.3. Inspection of welds: The inspection is conducted visually by personnel with appropriate expertise through experience and suitable training. For welds on pipelines subjected to tangential stress less than 20% of the specified minimum yield strength: - A certain number of welds must be randomly selected by the operating unit from regular inspections using X-ray photography, ultrasonic testing, magnetic particle testing, or other non-destructive testing methods. However, for welds at compressor stations, traffic intersections, major highway junctions, and railway crossings, a full inspection is required. - Visual inspection of pipeline sections must be performed on joints. Joints found to be defective must be repaired or removed from the pipeline system. - For welds on pipelines subjected to tangential stress equal to or greater than 20% of the specified minimum yield strength: - The quality of the welds will be visually inspected. - Any welds not meeting the requirements must be removed or repaired. - All tests, inspections, and repairs must be recorded in writing and retained by the operating unit.

2. 2.2. Requirements for corrosion control:

2. 2.2.1. External corrosion control:

a) For underground pipelines - Coating protection requirements: + The surface of the pipeline must be cleaned of harmful materials such as cleaning agents, rust, moisture, dust, oil, paint. The surface of the pipeline must be checked according to the rule of not protruding beyond the coating. Any defects or abnormalities must be removed. + The coating, corresponding joint fittings, and patching materials must be carefully selected to suit installation conditions, moisture absorption, operating temperatures of the pipelines, environmental factors (including the nature of the soil in contact with the coating), adhesion properties, and dielectric strength. + The coating must ensure effective adhesion to the pipeline. + The coating must be visually inspected for damage before the pipeline is installed. Electrical insulation coatings on power sources and power lines must be tested on holidays with appropriate measures. + Pipelines should be stored or arranged in a manner to minimize damage to the coating. - Cathodic protection requirements: + Cathodic protection does not need to be implemented in cases where it can be proven by inspection or non-destructive testing that this method is not necessary to ensure safety requirements. + All equipment or pipelines installed underground or buried with electrical insulation coatings must implement cathodic protection immediately upon commissioning, except for equipment with limited life spans. - Insulation requirements: + Every pipeline and equipment with a coating must be insulated at all joints with external systems including fuel pipelines. + Steel pipelines must be insulated from cast iron, ductile iron, and parts made of colored metals. + An electrical test must be conducted on the pipeline system to identify unexpected contacts with other metal equipment. If there are contacts, they must be eliminated immediately.

b) For above-ground pipelines: - Above-ground pipelines must be protected against corrosion by suitable coatings or casings. - The coated surface must be free of contaminants, such as corrosion products, moisture, rust flakes, dust, paint, etc. - The coating chosen must have characteristics suitable for the environment. This coating must ensure complete coverage of all exposed parts and meet the requirements or recommendations of the manufacturer.

2. 2.2.2. Internal corrosion control: If the gas transported in the pipeline does not contain corrosive substances as proven by testing, internal corrosion control measures are not necessary. When designing new pipeline systems, replacement, supplementary, or renovation of existing systems, one of the following internal corrosion control measures must be applied:

a) Using in-situ coating methods: - The coating layer must meet quality parameters and the minimum thickness of the dry coating layer must be calculated based on the type of coating and the coating method. - Strictly comply with regulations to prevent corrosion at joint locations. - When corrosion inhibitors are used as additives for gas flow: + The device for injecting corrosion inhibitors into the gas flow will be included in the design calculations. + The operation of this corrosion inhibitor injection process must be incorporated into the operating plan. + Monitoring equipment for this injection process must ensure continuous assessment of internal corrosion. + Corrosion inhibitors must not affect any component of the pipeline system.

b) Using in-pipe gas treatment methods: - Design separators or dehydrators. - Consider using equipment to remove contaminants from the gas flowing through the pipeline.

2. 2.3. Requirements for inspection and testing of gas pipeline systems:

2. 2.3.1. The results of all inspections and tests of any component of the gas pipeline system, along with the name and address of the person conducting such inspections and tests, must be retained with confirmation stamps and signatures attached.

2. 2.3.2. Requirements for design verification:

a) Design verification is conducted to confirm that the gas pipeline system meets safety requirements when in use. This process includes reviewing the following documents: - Raw materials and calculation documents for selecting raw materials. - Technical drawings describing the operational diagram and technical specifications of the gas pipeline system. - Safety measures to be applied to the pipeline system based on specific calculations for the pipeline environment and related conditions. - Operation, installation, and maintenance guidelines.

b) Design verification must be based on the following criteria: - The gas pipeline system has sufficient conditions to operate stably and safely. - Measures against both internal and external corrosion have been considered. - Suitable raw materials are selected according to the environment and other conditions ensuring pipeline safety. - Specific installation and usage guidelines are provided for each environmental condition. - Specific technical requirements and regulations for welding joints are established to ensure pipeline safety.

2. 2.4. Requirements for operation and maintenance:

2. 2.4.1. The operating entity must develop operation and maintenance procedures based on the provisions of this Standard, experience, knowledge, and other conditions where the pipeline system operates.

2. 2.4.2. To serve operation and maintenance tasks, the entity operating the gas pipeline system must:

a) Establish documents detailing operation and maintenance procedures in accordance with the Standard;

b) Develop written emergency response procedures for critical situations. An emergency response procedure chart must be posted at workstations so that any employee can follow initial steps to handle emergencies, such as whom to notify and how to shut down the system...

c) Operate and maintain pipeline system equipment in accordance with the established procedures;

d) Regularly revise and improve these procedures based on practical operational experience;

e) Conduct training for staff on operation and maintenance procedures;

f) Maintain records to manage the procedures and effectively train staff.

2. 2.4.3. Requirements for operation and maintenance procedures:

a) Detailed procedures and instructions must be provided for staff regarding routine operation and maintenance of equipment under normal operating and repair conditions.

b) Special attention must be given to clearly outline major risks threatening people in emergency situations.

c) There must be regulations for regular inspections along the entire length of the gas pipeline system or at key sections of the system.

2. 2.4.4. Requirements related to emergency response procedures:

a) Emergency response procedures must provide at least the following contents: - A section for receiving, identifying, and classifying emergencies requiring immediate response upon occurrence; - Clearly stating the responsibility for guiding employees in implementing the procedures and being accountable for training them in these procedures; - Identifying individuals responsible for updating the procedures; - Controlling emergency situations, including guidance for the first person to discover an incident; - Reporting and documenting emergency cases.

b) Training program: - The operating entity must have a training program for employees responsible for implementing emergency response procedures. - This program may be conducted through verbal instruction, documentation, and in some cases, group guidance and practice. - This program must be established and maintained continuously, and records of the program data must be kept to develop appropriate training programs for each employee.

3. Regulations on safety management in production, import, circulation, installation, and use of gas pipeline systems:

3. 1. Technical documentation of gas pipeline systems includes:

3. 1.1. General description; selection calculation of pipelines; durability and stability calculation of pipelines or their history;

3. 1.2. Overall drawings of the gas pipeline system with dimensions and main parameters;

3. 1.3. Detailed drawings of metal surfaces;

3. 1.4. Manufacturing processes for special components;

3. 1.5. Inspection and testing procedures;

3. 1.6. Safe installation and operation guidelines.

3. 2. Conditions for ensuring safety for domestically produced gas pipeline systems: Gas pipelines within the scope of this Standard must have:

3. 2.1. Complete technical documentation;

3. 2.2. Declaration of conformity and certification of conformity (according to conformity assessment method 8 stipulated in Circular No. 28/2012/TT-BKHCN dated December 12, 2012 of the Ministry of Science and Technology).

3. 2.3. Attach conformity marks before putting them on the market for circulation;

3. 2.4. Be subject to quality inspection and supervision by the product and commodity quality inspection agency under the Ministry of Labor, Invalids, and Social Affairs;

3. 3. Safety conditions for imported natural gas pipeline systems:

3. 3.1. Imported natural gas pipeline systems must comply with the provisions set forth in Section 3.1 and be announced as conforming and certified as conforming according to regulations by a designated certification organization in Vietnam or a foreign certification organization recognized pursuant to international treaties to which the Socialist Republic of Vietnam is a party or international agreements concluded by authorized agencies of the Socialist Republic of Vietnam;

3. 3.2. In cases where imported natural gas pipelines are exempted from quality inspection upon importation pursuant to bilateral or multilateral agreements between the competent authority of the Socialist Republic of Vietnam and exporting countries, such pipelines shall be exempted from import inspection;

3. 3.4. Imported natural gas pipelines that do not meet the requirements set forth in Section 3.1 above must be inspected at the point of entry by a designated or internationally recognized appraisal organization pursuant to international treaties to which the Socialist Republic of Vietnam is a party or international agreements concluded by authorized agencies of the Socialist Republic of Vietnam when imported;

3. 3.5. Imported natural gas pipelines must undergo quality inspection in accordance with prescribed procedures and will be subject to legal penalties if violations occur;

3. 4. Safety conditions for natural gas pipeline systems circulating in the market: Suppliers of natural gas pipeline systems circulating in the market must comply with the following requirements:

3. 4.1. Adhere to regulations during storage and circulation of natural gas pipelines as directed by the manufacturer to avoid damage or impact on pipeline quality;

3. 4.2. Attach conformity marks before putting them on the market for circulation;

3. 5. Requirements for installing natural gas pipeline systems: Natural gas pipeline systems may only be installed if the following conditions are met:

3. 5.1. Complete technical documentation is available;

3. 5.2. Domestic-produced natural gas pipelines must be certified as conforming and announced as conforming according to regulations. Imported natural gas pipelines must have completed customs procedures;

3. 5.3. All accompanying parts and components must be synchronized; if manufactured in collaboration with multiple manufacturers, ensuring technical characteristics is the responsibility of the system pipeline manufacturer;

3. 6. Requirements for units installing natural gas pipeline systems: Units responsible for installation, calibration, maintenance, and repair of natural gas pipeline systems must meet the following conditions:

3. 6.1. Have legal entity status and be registered by the competent authority to operate in this field;

3. 6.2. Have sufficient technical staff trained in specialized fields. A skilled workforce must be trained and certified in safety according to regulations;

3. 6.3. Possess adequate technical conditions and technological capabilities for installation, calibration, and repair work;

3. 6.4. Follow installation, operation, and usage guidelines provided by the manufacturer and ensure technical parameters of the natural gas pipeline system according to technical documentation;

3. 7. Management and safe use of natural gas pipeline systems:

3. 7.1. Natural gas pipeline systems must be operated, maintained, serviced, and regularly inspected according to the manufacturer's instructions;

3. 7.2. Safety requirements for using natural gas pipeline systems:

3. 7.2.1. Only use natural gas pipeline systems in good technical condition that have been technically inspected and found to meet requirements. Do not use systems with damaged critical components;

3. 7.2.2. Operate natural gas pipeline systems in accordance with their specified technical characteristics and flow rates as defined by the manufacturer (or redefined after renovation or repair by the management unit);

3. 7.2.3. Have emergency response plans and personnel always ready to address urgent situations;

3. 7.2.4. Implement safety measures to ensure safety for people, materials, equipment, and structures through which the natural gas pipeline system passes;

3. 7.2.5. Promptly address any discovered damages;

3. 7.2.6. Each natural gas pipeline system must maintain a logbook for regular maintenance, repairs, and replacement of parts as required by the manufacturer;

3. 7.2.7. Record the entire operational history of the natural gas pipeline system to monitor, maintain, and promptly identify any damages;

3. 7.2.8. The person responsible for technical management and operation of the natural gas pipeline system must receive basic training in their assigned duties, initial occupational safety and health training before being assigned tasks, annual refresher training, and obtain a safety training certificate as required; understand the natural gas pipeline system and the responsibilities they oversee; know relevant technical safety standards and regulations related to the natural gas pipeline system;

3. 7.2.9. Implement preventive and handling measures for accidental fires caused by leaks, electrical arcs, or flame cutting of pipes;

4. Technical safety inspection of natural gas pipeline systems

4. 1. Natural gas pipeline systems must undergo initial inspection before use, periodic inspections during use, and extraordinary inspections according to inspection procedures issued by the Ministry of Labor, Invalids, and Social Affairs. Technical safety inspections of natural gas pipeline systems must be organized by inspection organizations designated by the Department of Occupational Safety and Health under the Ministry of Labor, Invalids, and Social Affairs according to legal procedures;

4. 2. During the inspection process, inspection organizations and units managing and using natural gas pipeline systems must strictly adhere to technical safety inspection procedures for fixed metal natural gas pipeline systems issued by the Ministry of Labor, Invalids, and Social Affairs.

4. 3. Gas pipelines that have passed inspection and met requirements must be labeled according to regulations.

4. 4. The inspection cycle for fixed gas pipeline systems is an external inspection every three years and a comprehensive inspection every six years.

5. Supervision, inspection, and handling of violations

5. 1. Inspection and handling of violations in the implementation of this Standard shall be carried out by the State Labor Inspectorate.

5. 2. Quality control of production, import, circulation, and use of gas pipelines shall be conducted in accordance with the Product and Goods Quality Law.

6. Responsibilities of organizations and individuals

6. 1. Organizations and individuals responsible for manufacturing, importing, circulating, repairing, installing, managing, and using gas pipeline systems shall comply with the provisions of this Standard.

6. 2. This Standard serves as the basis for quality control agencies to conduct inspections and also as the basis for conformity assessment organizations to issue compliance certificates.

7. Implementation

7. 1. The Department of Occupational Safety and Health, Ministry of Labor, Invalids and Social Affairs shall be responsible for guiding and inspecting the implementation of this Standard.

7. 2. Local state labor management agencies shall be responsible for guiding, inspecting, and supervising the implementation of the provisions of this Standard.

7. 3. This Standard shall take effect six months from the date of signature.

7. 4. During the implementation process, if there are any difficulties, relevant agencies, organizations, and individuals shall promptly report to the Ministry of Labor, Invalids and Social Affairs for consideration and resolution.