Circular No. 08/2021/TT-BLDTBXH Issuing the Technical Safety Inspection Procedure for Metal Pipeline Systems for Compressed Gas, Liquefied Gas, and Dissolved Gas

CIRCULAR
Issuing Technical Safety Inspection Procedures for Metal Pipeline Systems Conveying Compressed Gas, Liquefied Gas, and Dissolved Gas
metal conductive for compressed gas, liquefied gas, dissolved gas

_______________

Pursuant to the Labor Safety Law on June 25, 2016;

Pursuant to Decree No. 14/2017/NĐ-CP dated February 17, 2017, of the Government, stipulating the functions, tasks, powers, and organizational structure of the Ministry of Labor, Invalids, and Social Affairs;

Pursuant to Decree No. 44/2016/NĐ-CP dated May 15, 2016 of the Government detailing certain provisions of the Labor Safety Law regarding technical safety inspection activities, occupational safety training, and labor environment monitoring;

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

The Minister of Labor, Invalids, and Social Affairs issues this Circular to issue Technical Safety Inspection Procedures for Metal Pipeline Systems Conveying Compressed Gas, Liquefied Gas, and Dissolved Gas.

Article 1. Attached to this Circular are Technical Safety Inspection Procedures for Metal Pipeline Systems Conveying Compressed Gas, Liquefied Gas, and Dissolved Gas, designated as QTKĐ: 31-2021/BLDTBX.

Article 2. This Circular takes effect from September 15, 2021.

Article 3. MINISTRIES, GOVERNMENT AFFILIATED AGENCIES, GOVERNMENT BODIES, PEOPLE'S COMMITTEES OF PROVINCES AND MUNICIPALITIES DIRECTLY UNDER THE CENTRAL GOVERNMENT AND ASSOCIATED ORGANIZATIONS AND INDIVIDUALS ARE RESPONSIBLE FOR ENFORCING THIS CIRCULAR./.

   

TECHNICAL SAFETY INSPECTION PROCEDURES FOR METAL PIPELINE SYSTEMS CONVEYING COMPRESSED GAS, LIQUEFIED GAS, AND DISSOLVED GAS, DESIGNATED AS QTKĐ: 31-2021/BLDTBX
(Attached to Circular No. 08/2021/TT-BLDTBX dated August 30, 2021 of the Minister of Labor, Invalids, and Social Affairs)

 

Article 1. Scope of Regulation

Article 1. These Technical Safety Inspection Procedures for Metal Pipeline Systems Conveying Compressed Gas, Liquefied Gas, and Dissolved Gas (hereinafter referred to as the Procedures) shall apply to initial, periodic, and extraordinary technical safety inspections of metal pipeline systems conveying compressed gas, liquefied gas, and dissolved gas with working pressure of 0.7 bar or higher (hereinafter referred to as pipeline systems) under the management authority of the Ministry of Labor, Invalids, and Social Affairs as stipulated in Appendix Ib of Decree No. 44/2016/NĐ-CP dated May 15, 2016 of the Government detailing certain provisions of the Labor Safety Law regarding technical safety inspection activities, occupational safety training, and labor environment monitoring.

Article 2. These Procedures shall not apply to the following pipeline systems:

a) Pipeline systems conveying liquefied petroleum gas, natural gas, and other petroleum products.

b) Pipeline systems conveying steam and hot water.

c) Pipeline systems conveying gases used in the medical field.

Article 2. Applicability

These Procedures shall be applied to organizations engaged in technical safety inspections, technical safety inspectors, and related organizations and individuals.

Article 3. Terminology and Definitions

In these Procedures, some terms and definitions are understood as follows:

1. Metal Pipeline System Conveying Compressed Gas, Liquefied Gas, and Dissolved Gas (the aforementioned gases are collectively referred to as media) is a system consisting of pipelines and pipeline accessories for conveying media from one point to another.

Pipeline accessories are mechanical parts compatible for connecting or installed in the system, including pipe fittings (couplings, elbows, tees, flanges, gaskets, bolts, and other pipe fittings), various types of valves, flexible hoses, expansion compensators, filters, separators, measuring devices, and other compatible mechanical parts.

2. Initial Technical Safety Inspection is a technical safety inspection activity conducted after installation but before the first use of the system.

3. Periodic Technical Safety Inspection is a technical safety inspection activity carried out after the expiration of the previous inspection period.

4. Extraordinary Technical Safety Inspection is a technical safety inspection activity performed in the following cases:

a) After repair, upgrade, or modification that affects the technical safety condition of the pipeline system.

b) After relocation.

c) When the pipeline system has been idle for 12 months or more.

d) Upon request of the facility or competent authority.

Article 4. Steps for Inspection

1. When inspecting the technical safety of pipeline systems, the technical safety inspection organization must carry out sequentially according to the following steps:

a) Inspect technical documentation of the pipeline system.

b) Conduct external and internal technical inspections.

c) Perform testing technical inspections.

d) Conduct operational inspections.

đ) Process inspection results.

2. The subsequent inspection steps can only be carried out when the inspection results from the previous step meet the requirements. All inspection results at each step must be fully recorded in the inspection report according to the model prescribed in the Appendix issued together with this Procedure and kept fully at the inspection organization.

Article 5. Equipment and Tools for Inspection

1. Equipment and tools for inspection must be inspected and calibrated as prescribed.

2. Equipment and tools for inspection include:

a) Hydraulic test pumps.

b) Air compressors, pressure generating equipment, or compressed air cylinders, inert gas cylinders.

c) Pressure gauges with appropriate accuracy levels and scales.

d) Non-destructive defect detection equipment using endoscopic methods.

đ) Dimensional measurement tools and equipment.

e) Bubble spray bottles, soap bubble solutions, or gas leak detection equipment.

g) Pipe clamps.

h) Insulation resistance measuring equipment.

i) Ground resistance measuring equipment.

k) Temperature measuring equipment.

l) Light intensity measuring equipment.

m) Ultrasonic thickness measuring equipment (if necessary).

n) Non-destructive defect detection equipment (if necessary).

Article 6. Conditions for Inspection

When conducting pipeline system inspections, the following conditions must be ensured:

1. The pipeline system must be in a state ready for inspection.

2. Technical documentation of the pipeline system must be complete.

3. Environmental and weather factors must not affect the inspection results.

4. Safety and hygiene conditions for labor must be met to conduct pipeline system inspections.

Article 7. Preparation for Inspection

Before conducting inspections, the following preparatory work must be carried out:

1. Unify the inspection plan, preparation work, and coordinate with the user facility to prepare the following contents:

a) Prepare technical documentation of the pipeline system.

b) Isolate, remove media, clean inside and outside the pipeline system.

c) Prepare facilities to ensure all parts of the pipeline system can be examined.

d) Prepare human resources and materials for inspection; assign personnel to participate and witness the inspection.

2. Inspect technical documentation of the pipeline system

a) Initial technical safety inspection

- Inspect design documentation (if available) with the main contents as follows:

+ Requirements for metal material and welding joints.

+ Calculations of strength or standards defining technical parameters related to the durability of pressurized components.

+ Pipeline system schematic drawings.

+ Basic parameters of the system.

+ Requirements for measuring devices; grounding, lightning protection, protective equipment (if applicable).

- Inspect installation and completion documentation with the main contents as follows:

+ Name of the installation and user facility; basic parameters of the system.

+ As-built drawings;

+ Characteristics of additional materials added during installation;

+ Certificates of quality inspection for metal materials.

+ Welding data such as: location of welds, welding technology, electrode codes, welder names, and results of quality inspection of welds.

+ Calculations of strength or standards defining technical parameters related to the durability of pressurized components (when there is no design documentation).

+ Overall acceptance reports of the pipeline system.

+ Calibration reports of measuring devices; grounding, lightning protection, and protective equipment inspection reports (if applicable).

+ Operation, maintenance, and repair instructions.

b) Periodic technical safety inspection

Inspect the documentation as in the initial inspection and supplementarily check the following documentation:

- Inspect the pipeline system history, inspection reports, and Certificate of Inspection Results from the previous inspection.

- Inspect usage management, operation, maintenance documentation, and inspection reports (if applicable).

c) Abnormal technical safety inspection

Inspect and review documentation as in the periodic technical safety inspection and supplementarily check other documentation specified in the following cases:

- In case of repairs, renovations, upgrades: repair, renovation, upgrade design documentation, post-repair, renovation, upgrade acceptance reports.

- In case of relocation: review installation documentation.

d) Evaluate the inspection documentation results

The results meet the requirements when:

- The pipeline system documentation is complete and meets the above inspection requirements.

- If not, the facility must take supplementary measures to address the issues.

3. Fully prepare suitable inspection tools to serve the inspection process.

4. Develop and unify the implementation of safety measures with the facility before inspection. Equip sufficient personal protective equipment to ensure safety during the inspection process.

Article 8. Conducting inspection

When conducting inspection, it must be carried out in the following sequence:

1. External technical inspection:

a) Inspect the ground surface and installation position compared to the technical drawings and documents of the pipeline system.

b) Inspect the lighting operation system and ventilation system (if any) compared to the technical drawings and documents of the pipeline system. In cases where the pipeline system uses hazardous or flammable substances, it is necessary to inspect the ventilation system and pay attention to inspecting at the source supply area, substance usage area, and safety valve exhaust areas.

c) Inspect the work floor, staircase, and hanging racks compared to the technical drawings and documents of the pipeline system.

d) Inspect the electrical grounding safety system and lightning protection system (if any) compared to the technical drawings and documents of the pipeline system.

đ) Inspect the technical parameters on the labels of the pipeline system and components within the pipeline system compared to the technical drawings and documents of the pipeline system.

e) Inspect the status of safety devices, measuring instruments, and auxiliary equipment in terms of quantity, type, and technical parameters compared to the technical drawings and documents of the pipeline system.

g) Inspect various types of pipes, valves, and pipeline accessories installed on the pipeline system in terms of quantity, type, and technical parameters compared to the technical drawings and documents of the pipeline system.

h) Inspect the status of other auxiliary equipment accompanying the pipeline system for its operational process.

i) Inspect the welding conditions, metal surface of pressure-bearing parts of the pipeline system. If there is any doubt, require the facility to apply appropriate supplementary inspection measures to evaluate more accurately.

k) The technical condition of the paint layer, thermal insulation layer (if any) must comply with the technical drawings and documents of the pipeline system; inspect water accumulation under the thermal insulation layer.

l) Inspect joint details.

m) Evaluate the results of external technical inspection

The results meet the requirements when:

- The inspection results must comply with the technical drawings and documents of the pipeline system.

- There should be no cracks, bulges, dents, or signs of substance leakage on the pressure-bearing parts of the pipeline system.

- The minimum wall thickness of the pipe at locations reduced due to scratches, pitting, corrosion must ensure the corresponding strength calculation for the maximum working pressure of the pipeline system or within the corrosion limit specified in the technical drawings and documents of the pipeline system.

2. Internal technical inspection

a) Inspect the metal surface condition of the pressure-bearing parts of the pipeline system.

b) Inspect the dirt, rust, and internal metal wall corrosion condition of the pipeline system.

c) For positions that cannot undergo internal inspection during testing, the technical condition inspection must be conducted according to the manufacturer's technical documentation. The documentation must clearly state the items, methods, and inspection procedures.

d) When internal inspection is not possible due to the structural characteristics of the pipeline system, allow the internal inspection to be replaced by a strength test as stipulated in point c, Clause 3, Article 3 of this Decree and inspect the accessible parts.

đ) Evaluate the results of internal technical inspection

The results meet the requirements when:

- The pipeline system condition is normal, without any cracks, bulges, or dents.

- The minimum wall thickness of the pipe at locations reduced due to scratches, pitting, corrosion must ensure the corresponding strength calculation for the maximum working pressure of the pipeline system or within the corrosion limit specified in the technical drawings and documents of the pipeline system.

3. Technical inspection and testing

a) If the pipeline system has multiple sections operating at different pressures, each section must be tested separately according to their respective pressures.

b) During inspection, isolation measures must be taken to ensure that automatic protective devices and measuring instruments are not destroyed at test pressure. If this cannot be guaranteed, these devices must be removed.

c) Strength Test

The strength test period shall not exceed once every six years and must be conducted with the following requirements (including abnormal inspections):

- The test medium is liquid (water, non-corrosive, non-toxic, non-flammable liquid) or gas (inert gas or air), with a temperature below 50°C and not lower than the ambient temperature by more than 5°C.^°C and not exceeding five degrees above ambient temperature^°4. Liquid bull semen

- Test Pressure

+ Pipeline test pressure is defined as follows:

Table: Pipeline Test Pressure

 

+ In cases where the pipeline test pressure is equal to or lower than the pressure vessel test pressure in the system, the pipeline test is conducted together with the pressure vessel in the system at the pipeline test pressure specified in the table of point c, Clause 3, Article 3 of this Decree.

+ In cases where the pipeline test pressure is higher than the pressure vessel test pressure in the system and isolation from the pressure vessel is not possible, the pipeline test is conducted together with the pressure vessel in the system at the pressure vessel test pressure but must be accepted by the user and must not be less than 77% of the pipeline test pressure specified in the table of point c, Clause 3, Article 3 of this Decree.

- Duration of maintaining test pressure: 10 minutes.

- Specific procedure for strength test as follows:

+ Load test medium: Fully load the test medium into the pipeline system (note to vent gases when using liquid).

+ Increase pressure to the test pressure (note to increase gradually to avoid sudden expansion damaging equipment and strictly prohibit hammering at test pressure). Monitor and detect any abnormalities during the test.

+ Maintain the test pressure as prescribed.

+ Gradually reduce pressure to the working pressure, maintain this pressure throughout the inspection process. Then reduce pressure to 0 (zero); rectify any deficiencies (if any) and re-inspect the rectified results.

- In cases where liquid strength testing is not feasible due to stress on foundations, floors, or difficulty in draining water, allow replacement with gas pressure testing (air or inert gas). Gas strength testing is only allowed if external and internal inspections yield good results and strength calculations based on direct measurements on the pipeline system are satisfactory. When conducting gas testing, the following safety measures must be applied:

||| Van and pressure gauges on the gas charging pipeline must be moved away from the pipeline installation location or placed outside the pipeline enclosure.

||| During the time the pipeline is under gas pressure testing, unauthorized personnel must move to a safe location.

||| It is strictly prohibited to strike any part of the pipeline system with a hammer during pressure testing.

||| - Evaluate the results of the endurance test:

||| The test results meet requirements when:

||| + There are no signs of cracking.

||| + No bubbles, dust, or water leakage are found at the welds or connections.

||| + No deformation is detected.

||| + The allowable pressure drop during the maintenance of the test pressure does not exceed 3% of the test pressure.

||| d) Leak Testing

||| The pipeline system must undergo a leak test after the endurance test or for pipeline systems conveying flammable, explosive, toxic, or corrosive substances:

||| - Test medium: Air or inert gas

||| - Test pressure: P (maximum operating pressure)._Pmax ||| - Duration of maintaining test pressure: At least thirty minutes.

||| - Procedure:

||| + Fill the test medium, gradually increase the pressure to the test pressure, then cut off the supply source.

||| + Conduct a check using soapy water, a foam sprayer, or a device that detects gas leaks; inspect at the welds, flanges, threaded joints, valve connections, and original pipeline.

||| - Evaluate the results of the leak test

||| + The pressure remains constant at the test pressure.

||| The test results meet requirements when:

||| + No gas leaks are detected.

||| 4. Operation Testing:

||| a) Verify all conditions necessary to put the pipeline system into operation.

||| b) Check the operational status of the pipeline system and its accessories, the functioning of measuring and protective devices.

||| c) Safety valves are calibrated and sealed as follows: the set pressure of the safety valve shall not exceed 1.1 times the maximum operating pressure.

||| d) Evaluation of Results: The results meet requirements when the pipeline system, auxiliary equipment, and measuring and protective devices operate normally, and working parameters remain stable.

||| Article 9. Handling Inspection Results

||| 1. Prepare an inspection report containing all required information according to the model provided in the Appendix attached to this Procedure.

||| 2. Approve the inspection report:

||| a) Mandatory participants in approving the inspection report include:

||| - A representative of the facility or a person authorized by the facility.

||| - A person assigned to participate in and witness the inspection.

||| b) When the report is approved, the inspector, the witness, and the facility representative or a person authorized by the facility sign and stamp (if applicable) the report. The inspection report is prepared in two (02) copies, each party retains one copy.

- Inspector conducting the inspection.

||| 3. Summarize the inspection results in the pipeline system's record (clearly state the inspector's name and date of inspection).

||| 4. Affix an inspection label: Only when the pipeline system meets technical safety requirements can the inspector affix a label. The label should be placed in a visible position.

||| 5. Certify the inspection results:

||| a) When the pipeline system passes the technical safety inspection, the inspection organization issues a certificate of inspection results to the pipeline system within five working days from the date of approval of the inspection report at the facility.

||| b) If the pipeline system fails to meet the requirements, only the provisions of Clause 1 and Clause 2 of this Article will be implemented, and only an inspection report will be issued to the facility, clearly stating the reasons why the pipeline system did not meet the inspection requirements, recommending corrective actions and deadlines for implementation; simultaneously send the inspection report and notification to the local labor management authority where the pipeline system is installed and used.

b) When the pipeline system inspection does not meet the requirements, only the provisions of Clause 1 and Clause 2 of this Article shall be implemented, and only issue to the entity the inspection report, which must clearly state the reasons why the pipeline system fails the inspection requirements, recommend corrective actions for the entity, and specify the deadlines for implementing these recommendations; at the same time, send the inspection report and notification to the local labor administrative authority where the pipeline system is installed and used.

Article 10. Inspection Period

1. The regular technical safety inspection period is three years. For pipeline systems using flammable, explosive, toxic, or metal-corrosive substances, or other pipeline systems that have been in use for over twelve years, the regular technical safety inspection period is two years.

2. For pipeline systems using flammable, explosive, toxic, or metal-corrosive substances that have been in use for over twelve years, or other pipeline systems that have been in use for over twenty-four years, the regular technical safety inspection period is one year.

3. In cases where the manufacturer specifies or the facility requests a shorter technical safety inspection period, such requirements shall be followed according to the manufacturer's regulations or the facility's request.

4. When shortening the technical safety inspection period, the inspector must clearly state the reasons in the inspection report.

5. When the technical safety inspection period is specified in national technical standards, it shall be carried out in accordance with the provisions of those standards./.

 

ANNEX

MODEL TECHNICAL SAFETY INSPECTION REPORT FOR PIPELINE SYSTEMS CARRYING COMPRESSED GAS, LIQUEFIED GAS, AND SOLUBLE GAS

(Attached to the Inspection Procedure for Metal Pipeline Systems Carrying Compressed Gas, Liquefied Gas, and Soluble Gas, Code QTKĐ: 31-2021/MOLISA)

 

(Name of Inspection Organization)

________

 

SOCIALIST REPUBLIC OF VIETNAM

Independence - Freedom - Happiness

________________________

No.: No.: ... / ...-DA

 

 

TECHNICAL SAFETY INSPECTION REPORT FOR PIPELINE SYSTEMS CARRYING COMPRESSED GAS, LIQUEFIED GAS, AND SOLUBLE GAS

Number:              

 

We include:

1…Inspector number:…

2…Inspector number:…

Belongs to:...

Registration Number of the Inspection Organization:...

Inspection was conducted on: …

Of (clearly state the name of the facility):…

Address (main office of the facility):…

Installation location address:…

Applied inspection procedure:…

Witnessed inspection and approved the report:…

1…Position: …

2…Position: …

I - BASIC DATA OF THE SYSTEM

Model number, code:…

Total length:…m

Working medium:…

Manufacturer (installer):…Year manufactured (installed):…

Purpose:…

Most recent inspection date…Conducted by:…

Most recent pressure test date: …,.. Conducted by….

Design pressure: …bar

Outer diameter of pipe: …mm... Operating pressure: …bar

Design temperature: … ^°C      Operating temperature: … ^°C

(In case the pipeline system consists of sections operating at different pressures, additional parameters for each section should be recorded: design pressure; operating pressure; outer diameter of pipe; design temperature; operating temperature).

II - INSPECTION FORM

First time □       Regular □                  Unusual □

Reason for unusual inspection: …

III - INSPECTION CONTENT

1. Review of documents and records pursuant to Clause 2, Article 7 of the procedure:

- Observation:    

- Evaluation result:   Pass □                       Fail □

2. External and internal technical inspection:

 

- Observation: …

- Evaluation result:             Pass □                       Fail □

3. Testing:

3.1. Measuring instruments for testing:

 

3.2. Testing:

 

- Observation: …

- Evaluation result: Pass □ Fail □

4. Evaluation of operational inspection results:      Pass □ Fail □

IV - CONCLUSION AND RECOMMENDATIONS

1. The inspected pipeline system has the following result: Pass □ Fail □

2. Inspection label number:                 Attached at…location:          

3. Operating pressure: …bar Operating temperature: … ^°4. Liquid bull semen

4. Set pressure of the system safety valve:

System opening pressure: …bar System closing pressure: …bar

In case the system consists of multiple sections operating at different pressures, specify the set pressure of the safety valve for each section.

5. Recommendations:                

Implementation time for recommendations: …

V - INSPECTION PERIOD

Next regular inspection date…month…year

Reason for shortened period…

Report approved on…month…year…

At: ...

The report is made in…copies, each party retains…copy./.

 

ESTABLISHMENT OWNER

Commitment to fully implement all recommendations within the stipulated timeframe

(Signature, full name)

 

PARTICIPANTS WITNESSING THE INSPECTION

(Signature, stamp)

 

INSPECTORS

(Signature, stamp)