2. DOCUMENTARY MATERIALS
- QCVN: 01-2008 / BLDTBXH - National technical regulation on labor safety of boilers and pressure vessels.
-TCVN 6156: 1996 - Pressure vessels - Technical requirements for installation safety, use, repair, testing methods.
- TCVN 8366: 2010 - Pressure vessels - KTAT requirements on design, structure, fabrication.
- Gas bottle - Carbon steel gas bottle - Test and test periodically.
- Bottles of gas - Reed and transported steel bottles used for liquefied petroleum gas (LPG). - Design and structure.
- Gas bottle - Refillable steel bottle used for liquefied petroleum gas (LPG). - Periodic inspection and testing.
- TCVN 6008: 2010 - Pressure welding equipment - Technical requirements and testing methods.
In cases where the national technical regulations and standards referred to in this verification process are supplemented, modified or replaced, the provisions of the latest documents shall apply.
The verification of technical safety criteria of re-usable steel cylinders used for liquefied petroleum gas (LPG) may be applied in accordance with other standards at the request of the manufacturer using Compliance with the standard must have technical specifications of safety
equal to or better than those specified in the national standards invoked in this process.
3. TERMS AND DEFINITIONS
This procedure uses the terms defined in the references cited above and some terms defined in this process are construed as follows:
3.1. Liquefied petroleum gas
Is a petroleum hydrocarbon product with a major component of propane (C3H8) or butane (C4H10) or a mixture of the two. At normal temperatures and pressures, these hydrocarbons are in the gaseous state and when compressed to a certain pressure or cooled to an appropriate temperature they convert to liquid form.
3.2. Steel LPG bottle:
Refillable and transportable LPG cylinders containing 0.5 liters to 150 liters of water are made of welded steel and labeled to meet the technical requirements of the national standard.
3.3. First Safety Technical Inspection:
An assessment of the technical state of safety of LPG cylinders in accordance with national technical regulations, safety standards after manufacture, before being put into use for the first time.
3.4. Periodical Safety Technical Inspection:
An assessment of the technical safety of LPG cylinders in accordance with national technical regulations and safety standards when the expiry of the pre-audit period expires.
3.5. Verification of abnormal safety techniques:
It is the assessment of the technical safety of LPG cylinders in accordance with national technical regulations and technical safety standards in the following cases:
- After repair, improvement affects the technical safety of LPG cylinders.
- Upon the request of a competent state agency or agency.3. TERMS AND DEFINITIONS
This procedure uses the terms defined in the references cited above and some terms defined in this process are construed as follows:
3.1. Liquefied petroleum gas
Is a petroleum hydrocarbon product with a major component of propane (C3H8) or butane (C4H10) or a mixture of the two. At normal temperatures and pressures, these hydrocarbons are in the gaseous state and when compressed to a certain pressure or cooled to an appropriate temperature they convert to liquid form.
3.2. Steel LPG bottle:
Refillable and transportable LPG cylinders containing 0.5 liters to 150 liters of water are made of welded steel and labeled to meet the technical requirements of the national standard.
3.3. First Safety Technical Inspection:
An assessment of the technical state of safety of LPG cylinders in accordance with national technical regulations, safety standards after manufacture, before being put into use for the first time.
3.4. Periodical Safety Technical Inspection:
An assessment of the technical safety of LPG cylinders in accordance with national technical regulations and safety standards when the expiry of the pre-audit period expires.
3.5. Verification of abnormal safety techniques:
It is the assessment of the technical safety of LPG cylinders in accordance with national technical regulations and technical safety standards in the following cases:
- After repair, improvement affects the technical safety of LPG cylinders.
- Upon the request of a competent state agency or agency.
4. STEP INSPECTION
4.1. For the first inspection bottle:
When expertising technical safety of LPG bottles for the first time, the organization of technical safety inspection must perform the following steps in turn:
- Check the record, resume the bottle;
- External, internal technical inspection;
- Technical testing of pressure ability (durable test);
- tight test;
- gas discharge and vacuum;
- Check the volume of the bottle;
- Processing test results.
Note. Next steps will be taken only when the test results in the previous step are met. All results of the step-by-step inspection shall be fully recorded in the field record in the form prescribed in Appendix 01 and fully archived at the inspection organization.
4.2. For periodical safety inspection bottles, abnormal:
When verifying the technical safety of bottles containing LPG periodically, abnormally, the organization of technical safety inspection must carry out the following steps in turn:
- Check the records, resume or information, documents of the bottle;
- External, internal technical inspection;
- Technical testing of pressure ability (durable test);
- Volume expansion test (for bottles used for more than 20 years);
- Literature test;
- tight test;
- gas discharge and vacuum;
- Check the volume of the bottle;
- Processing test results.
Note: Follow-up steps are only taken when the test results in the previous step are met. All results of the step-by-step inspection shall be fully recorded in the field record according to the form prescribed in Appendix 01 and fully archived at the inspection organization.
5. EQUIPMENT, TOOLS FOR INSPECTION OF LPG BOTTLES
The equipment and tools used for inspection must be suitable to the subject of inspection and must be inspected and calibrated according to regulations, including:
Equipment and tools for inspection of LPG cylinders include:
- Bottle valve fitting;
- Hydraulic testing equipment;
- Volume expansion tester;
- closed test equipment;
- Excess gas treatment equipment (if there is no condition for discharging into the environment);
- vacuum equipment;
- valve testing equipment;
- Equipment for checking the inside of bottles: lights, endoscopes;
- Pressure gauges, time;
- Weighing volume;
- number closing equipment;
- Mechanical measuring instruments: pair, ruler;
- Other necessary measuring, inspection and specialized equipment such as:
+ Metal thickness testing equipment;
Welding quality testing equipment.
6. CONDITIONS FOR INSPECTION
When conducting the inspection, the following conditions must be satisfied:
6.1. Bottles containing LPG must be ready for testing.
6.2. Records, documents and information of LPG cylinders must be adequate.
6.3. Environmental and weather factors do not affect test results.
6.4. Occupational safety and health conditions must be met for inspection.
7. PREPARATION PREPARATION
When conducting the inspection, the following preparation tasks must be carried out:
7.1. To agree on the verification plan, the work of preparation and coordination between the expertising organization and the grassroots, including the following contents:
7.1.1. Prepare records, documents of the bottle.
7.1.2. Identify the bottles to be tested:
- First Safety Technical Inspection: Select 5% random sample in the inspection batch (selected bottles must be representative of the sub-lot). If a bottle is found to be unsatisfactory, 100% of the bottles must be inspected (Article 4.2 TCVN 6156: 1996).
- Periodical safety inspection, abnormal safety inspection: 100% of bottles.
7.1.3. Make records of delivery, preparation of conditions on human resources and means of transportation to the place where the inspection is conducted.
7.1.4. Inspection and preliminary processing:
- To immediately remove bottles not owned by establishments or not recommended by authorized establishments;
- Remove immediately the bottles not on the list, with no or unknown parameters written on the book hand, the bottles with excessive defects evaluation removed such as bulging, mucilage, Cracking, fire damage, arc burns or welding torches;
Carry out the discharge and treatment of residual gas in the bottle, ensuring that the bottle is free from excess pressure and air;
- Clean surfaces outside the bottles (if needed).
7.2.Check the records, the history of the bottle
Based on the forms of verification for inspection, consider the following documents:
7.2.1. When testing for the first time:
7.2.1.1. Check the history of the batch: (according to form QCVN: 01-2008-BLDTBXH) note to consider the following documents:
- Indicators of manufacturing metals, welding metals;
- Calculate the strength of the parts under pressure;
- Drawings of full composition of main dimensions;
- Guidance on operation, maintenance, repair;
- Certificates of conformity will be issued by the designated organization in accordance with regulations,
In cases where the competent bodies have promulgated national technical regulations for the expertised objects.
7.2.1.2. Stocking records of the batch:
- Certificate of bottle manufacturer, applicable standards;
- Name and address of the customer who owns the bottle;
- Metal Fabrication Certificate;
- Minutes and tables showing the results of long-term durability testing;
- Weld test report;
- Minutes of results of dilatation test;
- Minutes of test results;
- Report on thickness and weld test results.
7.2.2. When testing safety techniques periodically:
7.2.2.1. Check the history of the bottle, the minutes of inspection and the results of the previous inspection, or information on the bottle.
1.22.2. Files on management of use and maintenance; Inspection, examination (if any).
7.2.3. When testing abnormal safety techniques:
7.2.3.1. Files on management of use and maintenance; Inspection, examination (if any).
7.2.3.2. Repair design dossiers, acceptance records after welding repair, replacement of pressure parts.
Evaluating the results of dossiers, CVs: The dossiers are satisfactory when they are complete and satisfy the requirements specified in Article 2.4 of QCVN: 01/2008 / BLDTBXH.
If not guaranteed, the facility must take additional remedies.
7.3. To prepare adequate means of accreditation for the accreditation process.
7.4. Develop and agree on the implementation of safety measures before the inspection. Fully equipped with tools, personal protective equipment, ensuring safety during the inspection process.
8. TEST INSPECTION
When conducting the inspection, the following procedures must be carried out:
8.1. For the first safety inspection bottle:
8.1.1. External technical inspection:
- Check the specifications of the bottle on hand compared to the shipment record of the bottle;
- Check the locket and valve lugs, check the condition of the surface, the welds, the base, the handles;
- Check the thickness of the bottle, compare with the specific manufacturing records: measured at the bottom of the bottle 3 points, the bottle 3 points, the bottle of 6 points divided by circumference;
- In case of doubt, the facility's requirements apply other appropriate testing methods.
Evaluation of results: The results are satisfactory when the condition of the normal parts, no abnormal phenomena, the parameters on the bottle in accordance with the records and labeling requirements.
8.1.2. Internal Technical Checklist:
- Remove the bottle valve from the bottle, avoiding collisions causing valve deformation or lace failure;
- Check inside the bottle with specialized equipment to assess the condition of metal surfaces, welds inside bottles;
- In case of doubt, the facility's requirements apply other appropriate testing methods.
Evaluation of results: The results are satisfactory when the condition inside the bottle is normal, no abnormality is present.
8.1.3. Technical testing of pressure resistance (durable test):
- It is possible to perform a durable test with each bottle or group of bottles according to the design of the durable system;
- Test fluid: Water;
- The pressure test pressure is labeled on the bottle, but not exceeding 10% or 2 bar (select smaller value) and not less than 30 bar. According to 5.4.2.4. D TCVN 7832: 2007;
- Time to maintain at the test pressure: minimum 1 minute;
- Order of durability testing:
Fill the bottle with water. Perform a gradual increase of the pressure in the bottle until the test pressure is reached, maintaining this pressure during the test period. During this period, the entire surface of the bottle, welds, deformities, cracks, leaks is checked. Then slowly lower the pressure down and flush out the water;
- If there is a leak in the pressure system, it must be repaired and then retest the bottles.
Evaluation of results: The durable test bottle is required when: The pressure does not decrease when maintained at the test pressure, no leakage on the bottle body, no welds or any visible deformation. .
8.1.4. Tail-free trial:
- It is possible to perform a sealed test with each bottle or group of bottles according to the design of the sealed test system;
- Test media: inert gas or gases;
- Test pressure: The test pressure written on the bottle or on request of the facility but not less than 13 bar;
- Time to maintain the test pressure: Minimum 5 + 7 seconds (Section 5.4.4.2.a TCVN 7832: 2007).
- Sequence test sequence:
Bottles shall be fitted with a stopper valve according to 7.4 TCVN 7832: 2007, charging the test media to the test pressure, completely disconnected from the pressure source and maintaining the pressure during the test. All the bottles will be immersed in water or another equivalent method and visually inspected for leaks on the entire surface of the bottle, welds, bottle neck joints and bottle valves. Bottles leaking at the valve mounting position must be carefully considered and must be retested in the correct order.
Result evaluation. Bottle tested to meet the requirements to ensure the tightness, no leakage at any point on the entire surface of the bottle, valve and junction between the valve and bottle neck.
Note: Light in the test area should be sufficiently bright for the naked eye to observe. Bottle water tanks must be cleaned and replaced regularly to ensure the transparency needed to observe the air bubbles. Once the bottled water is done, it is necessary to keep the water level quiet to conduct the inspection process.
8.1.5. Air discharge and vacuum:
- The bottles have been tested to meet the requirements of gas discharge and vacuum aspiration;
- The pressure in the bottle after vacuum reaches the value in the range of (0.3 - 0.5 bar).
8.1.6. Check the volume of the bottle:
Weigh and determine the volume (according to 10.2 TCVN 6292: 1997). Check and compare with the volume that the manufacturer has closed on the bottle. In case the bottles have a weight difference> 200g compared to the volume of the bottle on the bottle, the volume of the package should be closed according to the actual test.
8.2. For periodical safety inspection bottles, abnormal:
8.2.1. External technical inspection:
- Check the specifications of the hand-held bottle compared to the profile, profile or information of the bottle;
- Check the junction of bottle neck and valve, check condition of surface, welds, base, hand. Identification of physical defects, corrosion on bottles and other defects not to exceed the removal limit;
- In case of doubt, the facility requirements apply other appropriate testing methods such as thickness gauges etc.
Result evaluation:
- Bottles meet requirements when the condition of normal parts, no abnormal phenomena, the parameters on the bottle in accordance with the records and labeling regulations;
- Eliminate bottles with shelf life of more than 26 years;
Eliminate bottles with defects that exceed the removal limits in Table 1, Table 2, and Table 3 of Article 5.3 TCVN 7832: 2007.
8.2.2. Internal Technical Checklist:
- Remove the bottle valve from the bottle, avoiding collisions causing valve deformation or lace failure;
- Inspect the inside of the bottle with specialized equipment for assessing the condition of metal surfaces, welds, corrosion inside bottles;
- In case of doubt, the facility's requirements apply other appropriate testing methods.
Evaluate results: Bottles are satisfactory when the condition inside the bottle is normal, no abnormal phenomena.
8.2.3. Technical testing of pressure resistance (durable test):
- It is possible to perform a durable test with each bottle or group of bottles according to the design of the durable system;
- Test fluid: Water;
- The pressure test pressure is labeled on the bottle, but not exceeding 10% or 2 bar (select smaller value) and not less than 30 bar. According to 5.4.2.4.d TCVN 7832: 2007;
- Time to maintain at the test pressure: Minimum 01 minute;
- Order of durability testing:
Fill the bottle with water. Perform a gradual increase of the pressure in the bottle until the test pressure is reached, maintaining this pressure during the test period. During this period, the entire surface of the bottle, welds, deformities, cracks, leaks is checked. Then slowly lower the pressure down and flush out the water;
- If there is a leak in the pressure system, it must be repaired and then retest the bottles.
Evaluation results: The durable test bottle is required when: The pressure does not decrease while maintaining the test pressure, no leaks on the bottle body, the weld.
8.2.4. Volume expansion test:
- The volume expansion test must be carried out when the used bottle is checked for more than 20 years;
- Volume expansion tests were performed concurrently with durable testing.
Evaluate the result: Expansion volume required when volume expansion is less than 10% of the total volume expansion.
8.2.5. Check bottle valve:
- Visual inspection of the valve eye: Valves do not have distortion.
- Check thread condition to ensure the thread shape is appropriate, complete, no bavia, crack ....
- Check the tightness of the valve by compressed air with suitable pressure on the specialized valve tester.
Evaluate results: The bottle valve meets the requirements for normal conditions and is sealed, with no valve flaps or valve outputs.
8.2.6. Tail-free trial:
- It is possible to perform a sealed test with each bottle or group of bottles according to the design of the sealed test system;
- Test media: inert gas or gases;
- Test pressure: by the test pressure written on the bottle or on request of the facility but not less than 13 bar;
- Time to maintain the test pressure: minimum 5 + 7 seconds (Section 5.4.4.2.a TCVN 7832: 2007);
- Sequence test sequence:
Bottles shall be fitted with a stopper valve in accordance with 7.4 TCVN 7832: 2007, charging the test medium to the test pressure, completely disconnected from the pressure source and maintaining pressure during the test. The whole bottle shall be immersed in Water or other equivalent method and is visually inspected for leaks on all cylinders, welds, bottle joints and bottle valves. Bottles leaking at the valve mounting position must be carefully considered and must be retested in the correct order.
Evaluation of the result: The sealed bottle was satisfactory, ensuring no leakage at any point on the entire surface of the bottle, valve and the junction of the valve to the bottle neck.
Storage: Light in the test area should be sufficiently bright for the naked eye to observe. Bottle water tanks must be cleaned and replaced regularly to ensure the transparency needed to observe the air bubbles. Once the bottled water is done, it is necessary to keep the water level quiet to conduct the inspection process.
8.2.7. Air discharge and vacuum:
- The bottles have been tested to meet the requirements of gas discharge and vacuum aspiration;
- The pressure in the bottle after vacuum has reached the value of (-0.3 - - 0.5 bar).
8.2.8. Check the volume of the bottle:
Weigh and determine the volume (according to 10.2 TCVN 6292: 1997). Examine and compare with the volume of packaging the manufacturer has packed on the bottle;
- In the case of bottles with a weight difference> 200g compared to the volume of packaging on the bottle, the volume of the package must be closed according to the actual inspection;
- If the volume is over 95% of the original volume, remove the bottle.
9. HANDLING OF EXPERTISE RESULTS
9.1. For the first inspection bottle:
9.1.1. Make inspection records, list of bottles and bottles with the full contents in the form prescribed in Appendix 02, 03 attached to this process.
9.1.2. Pass the verification minutes.
Participants who pass the required verification must have at least the following members:
- The head of the inspectorate shall personally inspect the bottles;
- Examiners supervise the process of bottle testing;
- The head of the team directly inspects the bottle.
When the minutes are passed, the members will sign the minutes together.
9.1.3. Record the results of the verification on the CV of the batch (clearly state the full name of the inspector, date of inspection).
9.1.4 Close the verification number.
Sample bottles (of 5%) that meet the test requirements are affixed test marks. Close the verification mark consisting of the accredited organization, the time of verification and the time of re-inspection on the hand: [1]; [2]; [3]; [4] on the same line, where the closed length is limited, it is possible to separate [1] a row separately;
[1]: Logos or symbols of the inspection unit;
[2]: Month, year of verification (last two digits);
[3]: Next year accreditation (last two digits);
[4]: Volume of bottle (if volume changes over 0.2 kg).
Letter height, minimum 4mm. The re-inspection period must be in accordance with Article 10 of this procedure. Do not overwrite the figures already on hand.
9.1.5. Certification of test results:
9.1.5.1. When the bottles are assessed up to the technical safety requirements, the expertising organization shall grant the certificate of inspection results to the whole batch within 5 working days from the date of passing the inspection record at the establishment.
9.1.5.2. If there are at least one bottle of unsatisfactory quality in the inspection bottle, it must immediately notify the establishment thereof and make a record of the inspection, which must clearly state the reason that the bottles have been inspected not up to the requirements and requirements. Bridge bases test 100% of bottles in batches.
9.2. For periodical safety inspection bottles, abnormal:
9.2.1. Make the minutes of inspection, the list of bottles and bottles with the full contents in the form prescribed in Appendices 02 and 03 issued together with this process.
9.2.2. Pass the audit minutes:
Participants who pass the required verification must have at least the following members:
- The head of the inspectorate shall personally inspect the bottles;
- Examiners supervise the process of bottle testing;
- The head of the team directly inspects the bottle.
When the minutes are passed, the members will sign the minutes together.
9.2.3. Write the summary of the test results on the list of the batch (if any, the full name of the verifier, date of inspection).
9.2.4. Close the verification number.
Bottles that meet the verification requirements are affixed with verification marks. Verification marks include the accreditation body, the accreditation time and the re-inspection time on the hand: [1]; [2]; [3]; [4] on the same line, where the closed length is limited, it is possible to separate [1] a row separately;
[1]: Logos or symbols of the inspection unit;
[2]: Month, year of verification (last two digits);
[3]: Next year accreditation (last two digits);
[4]: Volume of bottle (if volume changes over 0.2 kg).
Letter height, minimum 4mm. The re-inspection period must be in accordance with Article 10 of this procedure. Do not overwrite the figures already on hand.
9.2.5. Certification of test results.
9.2.5.1. When the bottles are tested up to the technical safety requirements, the expertising organization shall issue the certificate of the bottle-testing results within 5 working days as from the date of passing the expertise records at the establishments.
9.2.5.2. For bottles that do not meet the requirements, only steps 9.2.1, 9.2.2, 9.2.3 and only the basis of inspection records should be written in which the reason for the bottle is not verified Request and coordinate with the establishment to remove the bottles according to Article 8. TCVN 7832: 2007. Records of discarded bottles must be kept at the accreditation body; At the same time, it shall send the verification minutes and notify the local state management agency in charge of labor of the place where the inspection station is located.
10. TERM RETRACTION PERIOD
10.1. The period of technical safety inspection periodically is 05 years. For bottles that have been in use for more than 20 years, the periodical safety inspection period is 02 years.
10.2. Where the manufacturer specifies or requires a shorter inspection time, the manufacturer's regulations and the requirements of the establishment shall apply.
10.3. When shortening the verification time limit, the auditors must clearly state the reasons therefor.
10.4. When the verification period is specified in the national technical regulations, the provisions of that regulation shall apply.
