What are conditions for inspection of technical safety of metal piping systems carrying compressed gases, liquefied gases and dissolved gases in Vietnam?

What are conditions for inspection of technical safety of metal piping systems carrying compressed gases, liquefied gases and dissolved gases in Vietnam?

Pursuant to Article 6 of the Procedures for inspection of technical safety of metal piping systems carrying compressed gases, liquefied gases and dissolved gases issued together with the Circular 08/2021/TT-BLĐTBXH stipulating conditions for inspection as follows:

The inspection must not be carried out unless the following conditions are met:

1. The piping system is at the ready for inspection.

2. Documents of the piping system are adequate.

3. The inspection is not affected by environment or weather.

4. Requirements concerning occupational safety and health are met.

What are regulations on preparation for inspection of technical safety of metal piping systems carrying compressed gases, liquefied gases and dissolved gases in Vietnam?

Pursuant to Article 7 of the Procedures for inspection of technical safety of metal piping systems carrying compressed gases, liquefied gases and dissolved gases issued together with the Circular 08/2021/TT-BLĐTBXH stipulating preparation for inspection as follows:

Before carrying out the inspection, it is required to make the following preparations:

1. Reach an agreement on the inspection plan and preparations and cooperate with the piping system user in:

a) Preparing documents and technical documentation of the piping system.

b) Isolating and removing working fluids, cleaning internal and external surfaces of the piping system.

c) Preparing facilities for examining all components of the piping system.

d) Providing personnel and materials for inspection; assign personnel to participate in and witnessing the inspection.

2. Inspect documents and technical documentation of the piping system

a) First inspection

- Regarding design document (if any), pay attention to the following:

+ Parameters for fabricated metal and welds.

+ Calculation of strength or standards specifying technical specifications related to strength of pressure retaining components.

+ Diagram of the piping system.

+ Basic specifications of the system.

+ Requirements for measuring equipment; grounding, lightning protection, protection equipment (if any).

- Regarding installation and as-built documents, pay attention to the following:

+ Name of the installer; basic specifications of the system.

+ As-built drawing

+ Characteristics of materials added upon installation;

+ Certificates of inspection of fabricated metal quality.

+ Welding data such as locations of welds, welding technology, welding electrode code, welder's name and weld quality test results.

+ Calculation of strength or standards specifying technical specifications related to strength of pressure retaining components (in the absence of the design document).

+ Entire piping system commissioning record.

+ Measuring equipment calibration reports; records on inspection of grounding, lightning protection and protection equipment (if any).

+ Guidelines for operation, maintenance and repair.

b) Periodic inspection

Documents shall be inspected as if it is the first inspection and the following shall be additionally inspected:

- Previous profile, inspection record and inspection result report.

- Documents on the use, operation and maintenance of the piping system; inspection record (if any).

c) Unscheduled inspection

Documents shall be inspected as if it is the unscheduled inspection and other documents shall be additionally inspected in the following cases:

- In case of repair, renovation or upgrade: documents on repair, renovation or upgrade or and commissioning record.

- In case of relocation: installation documents.

d) Evaluation

The document inspection result is satisfactory if:

- Documents of the piping system are adequate and satisfy the above-mentioned inspection requirements.

- If the result is unsatisfactory, the user shall take remedial actions.

3. Prepare suitable and adequate equipment for inspection.

4. Develop measures for ensuring safety and reach an agreement with the user before inspection. Provide adequate personal protective equipment to ensure safety during the inspection.

What are regulations on external inspection of technical safety of metal piping systems carrying compressed gases, liquefied gases and dissolved gases in Vietnam?

Pursuant to Clause 1 Article 8 of the Procedures for inspection of technical safety of metal piping systems carrying compressed gases, liquefied gases and dissolved gases issued together with the Circular 08/2021/TT-BLĐTBXH stipulating external inspection as follows:

1. External inspection:

a) Check installation area and location against those specified in the documents and technical documentation of the piping system.

If the piping system uses a toxic or explosive working fluid, check the ventilation system, especially at the source area, the area where the working fluid is used and outlet of the safety valve.

c) Check work platform, stairs and hangers against those specified in the documents and technical documentation of the piping system.

d) Check electrical safety grounding and lightning protection system (if any) against those specified in the documents and technical documentation of the piping system.

dd) Check the specifications on the piping system's label and particulars in the piping system against those specified in the documents and technical documentation of the piping system.

e) Check the condition of safety, measuring and ancillary equipment in terms of its quantity, type and technical specifications against those specified in the documents and technical documentation of the piping system.

g) Check pipes, valves and pipe fittings installed on the piping system in terms of their quantity, type and technical specifications against those specified in the documents and technical documentation of the piping system.

h) Check the condition of other ancillary equipment accompanied serving operation of the piping system.

i) Check the condition of welds and metal surfaces of pressure retaining components of the piping system. If any suspicion exists, request the user to take appropriate additional inspection measures to provide a more accurate evaluation.

k) Check the technical condition of the paint and thermal insulation coating (if any) against those specified in the documents and technical documentation of the piping system; check for signs of water stagnation under the thermal insulation coating.

l) Check joints.

m) Evaluate the external inspection result

The document inspection result is satisfactory if:

- The external inspection result shows that the documents and technical documentation of the piping system are conformed to.

- No crack, bulge, dent or sign of working fluid leakage in the pressure retaining components of the piping system is found.

- The minimum thickness of the pipe wall deteriorated by scratches, indentations or corrosion must pass the strength test conducted under the corresponding maximum working pressure of the piping system or fall within the corrosion limit specified in the documents and technical documentation of the piping system.

Best regards!