Circular No. 17/2021/TT-BLDTBXH Issuing the technical safety inspection procedure for industrial gas cylinders under the management authority of the Ministry of Labor, Invalids and Social Affairs

CIRCULAR

Issuing technical safety inspection procedures for industrial gas cylinders under the management authority of the Ministry of Labor, Invalids, and Social Affairs

^___________

Pursuant to the Labor Safety Law dated June 25, 2015;

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 Law on Occupational Safety and Health regarding technical safety inspection activities, occupational safety training, labor hygiene training, and workplace environmental monitoring;

Pursuant to Decree No. 140/2018/NĐ-CP dated October 8, 2018 of the Government amending and supplementing several decrees related to business conditions and administrative procedures within the scope of management of the Ministry of Labor, Invalids, and Social Affairs;

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

The Minister of Labor, Invalids, and Social Affairs hereby promulgates this Circular on issuing technical safety inspection procedures for industrial gas cylinders under the management authority of the Ministry of Labor, Invalids, and Social Affairs.

Article 1. Name and designation of the inspection procedure

This Circular issues the technical safety inspection procedure for industrial gas cylinders under the management authority of the Ministry of Labor, Invalids, and Social Affairs, designated: QTKĐ: 06-2021/BLDTBXH.

Article 2. Effective Date

1. This Circular shall take effect from January 1, 2022.

2. The technical safety inspection procedure number QTKĐ: 06-2016/BLDTBXH issued together with Circular No. 54/2016/TT-BLDTBXH dated December 28, 2016 of the Ministry of Labor, Invalids, and Social Affairs shall be repealed from the date this Circular takes effect.

Article 3. Implementation Organization

Clause 1. Ministries, ministerial-level agencies, government agencies, provincial People's Committees, centrally governed cities, and related organizations and individuals are responsible for implementing this Circular.

2. During implementation, if there are any difficulties, organizations, entities, and individuals are requested to report to the Ministry of Labor, Invalids, and Social Affairs for guidance and resolution.

TECHNICAL SAFETY INSPECTION PROCEDURE FOR INDUSTRIAL GAS CYLINDERS UNDER THE MANAGEMENT AUTHORITY OF THE MINISTRY OF LABOR, INVALIDS, AND SOCIAL AFFAIRS DESIGNATION: QTKĐ: 06-2021/BLDTBXH (Issued together with Circular No. 17/2021/TT-BLDTBXH dated November 15, 2021 of the Minister of Labor, Invalids, and Social Affairs)

This technical safety inspection procedure applies to initial, periodic, and extraordinary inspections of industrial gas cylinders with working pressure higher than 0.7 bar (hereinafter referred to as gas cylinders) under the national 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 Law on Occupational Safety and Health regarding technical safety inspection activities, occupational safety training, labor hygiene training, and workplace environmental monitoring. 

Article 1. Scope of Regulation

This inspection procedure does not apply to liquefied petroleum gas (LPG) cylinders.

1. Organizations conducting technical safety inspections (hereinafter referred to as inspection organizations).

Article 2. Applicability

2. Technical safety inspection officers.

3. Organizations and individuals managing, using, and owning industrial gas cylinders (hereinafter referred to as facilities).

4. State management agencies and related organizations and individuals.

Article 3. Referenced Documents

1. National technical regulation on occupational safety for boilers and pressure vessels QCVN:01-2008/BLDTBXH issued together with Decision No. 64/2008/QĐ-BLDTBXH dated November 27, 2008 of the Ministry of Labor, Invalids, and Social Affairs (hereinafter referred to as QCVN:01-2008/BLDTBXH).

2. National standard TCVN 6292:2013 Gas cylinder - Reusable welded steel gas cylinders published according to Decision No. 1475/QĐ-BKHCN dated June 12, 2013 of the Ministry of Science and Technology (hereinafter referred to as TCVN 6292:2013).

3. National standard TCVN 6294:2007 Gas cylinder - Welded carbon steel gas cylinders - Inspection and periodic testing published according to Decision No. 3213/QĐ-BKHCN dated December 31, 2007 of the Ministry of Science and Technology (hereinafter referred to as TCVN 6294:2007).

4. National standard TCVN 6295:1997 Gas cylinder - Seamless gas cylinders - Safety standards and characteristics (volume from 0.5 liters to 150 liters, unlimited pressure) published according to Decision No. 2123/QĐ-BKHCN dated April 5, 2018 of the Minister of Science and Technology (hereinafter referred to as TCVN 6295:1997).

5. National standard TCVN 6871:2007 Gas cylinder - Acetylene dissolved transport cylinders - Inspection and periodic maintenance published according to Decision No. 3213/QĐ-BKHCN dated December 31, 2007 of the Ministry of Science and Technology (hereinafter referred to as TCVN 6871:2007).

6. National standard TCVN 6156:1996 Pressure vessel - Technical safety requirements for installation, use, repair - Testing methods published according to Decision No. 1596/QĐ-TĐC dated July 26, 1996 of the Ministry of Science and Technology (hereinafter referred to as TCVN 6156:1996).

In cases where the national technical regulations and national standards referenced in this inspection procedure are amended, supplemented, or replaced, they shall be implemented according to the newly issued documents.

In the case where national technical standards and national standards cited in this Calibration Procedure are amended, supplemented, or replaced, they shall be implemented according to the newly issued document.

Article 4. Terminology, Definitions

In this Inspection Procedure, certain terms and definitions shall be understood as follows:

1. Industrial gas cylinder means a cylinder used to contain, transport industrial gases, liquefied gases, dissolved gases under pressure greater than atmospheric pressure and with a capacity up to 150 liters, manufactured and labeled in accordance with the provisions of National Standards TCVN 6292:2013 and National Standard TCVN 6295:1997.

2. Initial technical safety inspection means the activity of assessing the technical safety condition of industrial gas cylinders according to national technical regulations and safety technical standards after manufacturing but before their first use.

3. Periodic technical safety inspection means the activity of assessing the technical safety condition of equipment according to national technical regulations and safety technical standards at the end of the previous inspection period.

4. Unusual technical safety inspection means the activity of assessing the technical safety condition of equipment according to national technical regulations and safety technical standards after repair, replacement, processing that affects the technical safety condition of the cylinder, or when required by the entity or competent authority.

Article 5. Equipment and Tools for Inspection

The equipment and tools for inspection must be inspected and calibrated in accordance with the regulations. The equipment and tools for inspection include the following:

1. Non-destructive metal thickness testing equipment.

2. Gas residue handling equipment in cylinders.

3. Cylinder valve installation and removal equipment.

4. Hydrostatic test equipment for cylinders.

5. Leak test equipment for cylinders.

6. Volume expansion test equipment.

7. Internal cleaning equipment for cylinders.

8. Endoscopic internal inspection equipment.

9. Vacuum pump.

10. Electronic weighing scale.

11. Marking equipment for letters and numbers on cylinders.

12. Tool for inspecting porous material inside acetylene cylinders (as per Point 6.2 TCVN 6871:2007).

Article 6. Inspection Conditions

When conducting inspections of industrial gas cylinders, the following conditions must be ensured:

1. The cylinders must be in a state ready for inspection.

For cylinders containing gas that have been fully loaded before importation into Vietnam, they must undergo initial technical safety inspection according to the steps prescribed in Clause 1, Clause 2 of Article 8 of this Inspection Procedure (excluding the steps prescribed in Clauses 3, 4, 5, 6, 7, and 8 of Article 8 of this Inspection Procedure). A full inspection according to the provisions of Article 8 of this Inspection Procedure will only be carried out for cylinders prior to being reloaded with gas for subsequent use or those due for inspection as stipulated in Article 9 of this Inspection Procedure.

2. The documentation of the cylinders must be complete.

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

4. Safety and hygiene conditions must meet requirements for inspecting industrial gas cylinders.

Article 7. Preparation for Inspection

When conducting inspections of industrial gas cylinders, the following preparatory work must be carried out:

1. Unify the inspection plan, preparatory work, and coordination between the inspection organization and the entity, including the following contents:

a) Prepare the documentation of the cylinders.

b) Determine the cylinders to be inspected:

- Initial technical safety inspection: Randomly select 5% of the batch of cylinders to be inspected (the selected cylinders must ensure representation of each sub-batch of cylinders). If one cylinder does not meet the requirements among the inspected cylinders, then 100% of the cylinders in the batch must be inspected (Assessment according to Point 4.2 TCVN 6156:1996).

- Periodic technical safety inspection, unusual technical safety inspection: Inspect 100% of the cylinders.

c) Establish handover records, prepare human resources and means for transporting and gathering at the inspection site.

d) Conduct preliminary checks and handle:

- Immediately remove cylinders that are not owned by the entity or not authorized by the entity to request inspection;

- Remove cylinders not listed, without or unclear markings on the cylinder, cylinders with defects exceeding the evaluation criteria for removal such as swelling, denting, intersecting cut marks or puncture marks, cracks, damage from fire, burn marks from arc welding or cutting torches;

- Perform venting and handling residual gas remaining in the cylinders, ensuring that the cylinders are free of pressure and residual gas;

- Clean the outer surface of the cylinders if necessary.

đ) For cylinders that have been fully loaded with gas and stored in warehouses, when due for periodic inspection, they must be inspected at a rate of 5%.

- If the inspected cylinders meet the requirements, the remaining batch of cylinders may continue to be stored or used for up to one year;

- If any of the inspected cylinders do not meet the requirements, all remaining cylinders must be inspected at 100%, with the gas release time for 100% inspection of the batch not exceeding one month.

e) Prepare human resources, materials, and equipment to serve the inspection process; assign personnel to participate and witness the inspection.

2. Fully prepare appropriate inspection tools to serve the inspection process.

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

Article 8. Inspection Steps

When conducting technical safety inspections for industrial gas cylinders, inspectors must follow the inspection steps sequentially. The next step can only be carried out if the results from the previous step meet the requirements. The inspection steps include:

1. Step 1: Checking the documentation, history, or information and materials of the cylinder

Based on the inspection methods, the following technical documents shall be reviewed and examined:

a) For initial technical safety inspections:

- The batch history of the cylinders, technical files of the manufacturer (in accordance with the model specified in QCVN:01-2008/BLĐTBXH), noting the review of the following documents:

+ Specifications regarding the manufacturing metal and welding metal;

+ Calculations of the strength of pressure-bearing parts;

+ Construction drawings indicating all key dimensions;

+ Operation, maintenance, and repair instructions (if applicable);

+ Certificate of conformity issued by the designated organization according to regulations, in cases where the competent authority has issued national technical standards for the inspected object.

- Batch shipment documents:

+ Certificates of the manufacturer, applicable standards;

+ Name and address of the customer owning the batch;

+ Metal composition certificates;

+ Records and tables of results of durability tests and leak tests of the batch;

+ Reports on mechanical property testing of welds;

+ Records of volume expansion test results;

+ Records of explosion test results;

+ Records of thickness and weld test results (if applicable).

b) For periodic technical safety inspections:

- Review the batch history, inspection records, and certificate of inspection results from the previous inspection or information and materials about the cylinder.

- Management usage files, maintenance records, inspection reports (if applicable).

c) For unscheduled technical safety inspections: Review the batch history, certificate of inspection results, previous inspection records, and supplementarily check the relevant documents in the following specific cases:

- Management usage files, maintenance records, inspection reports (if applicable).

- Design documents for repairs, acceptance records after repairs involving replacement of pressure-bearing parts by welding.

Evaluation of the results of the documents and history: The documents meet the requirements when they are complete and comply with the provisions at point 2.4 QCVN: 01/2008/BLĐTBXH. If not met, the facility must take additional measures to rectify.

2. Step 2: External Technical Inspection

a) Check the technical specifications marked on the handle or neck of the cylinder, compare the technical data in the list of cylinders to be inspected. Remove cylinders that are not listed for inspection and those missing or unclear specifications.

b) Inspect the surface condition, welds, base, and handle (if present).

c) If there is doubt during visual inspection, apply additional tests or non-destructive inspection methods such as ultrasonic thickness measurement, weld inspection (if applicable) or other non-destructive methods.

d) Evaluation of results: The cylinder meets the requirements when its components are normal, without any abnormal conditions, and the specifications on the cylinder match the documentation. Remove cylinders according to point 4.8 TCVN 6156:1996, Appendix C TCVN 6294:2007, and Appendix C TCVN 6871:2007.

3. Step 3: Internal Technical Inspection

a) Before opening, inspect the internal components of the cylinder, ensuring that there is no residual pressure and that the concentration of harmful substances (if present) is within permissible limits.

- Cylinders containing inert gases, non-toxic gases, and non-explosive gases may be directly vented.

- Cylinders containing toxic gases and flammable/explosive gases must be processed using specialized equipment to recover the remaining gas, which can be reused or safely disposed of, and must not be directly released into the environment.

b) Remove the cylinder head valve carefully to avoid impact causing deformation or damage to the valve or thread.

c) Check the seal of the valve and safety device (if present); remove valves that do not meet the requirements.

d) Clean the inside of the cylinder (For acetylene cylinders containing porous material, cleaning is not performed but the quality of the porous material must be checked according to the manufacturer's instructions or TCVN 6871:2007).

đ) Inspect the inside of the cylinder using specialized viewing equipment to assess the condition of the metal surface and welds (not applicable for dissolved acetylene cylinders).. If there is doubt, require the facility to apply appropriate additional inspection methods.

e) Evaluation of results: The cylinder meets the requirements when the internal condition is normal, without any abnormal conditions. Remove cylinders according to point 4.8 TCVN 6156:1996.

4. Step 4: Pressure Resistance Testing (Durability Test)

Durability testing is not conducted for cylinders containing porous material.

a) Test medium, test pressure, and duration maintained at pressure as specified in Table 1.

Table 1: Test Pressure, Medium, and Duration of Durability Test

d) For non-liquid testable cylinders, conduct the test using compressed air or inert gas.

- Before starting the gas test, calculate and verify the durability based on direct measurements on the cylinder.

- Safety measures during gas testing:

+ The gas supply valve and sample pressure gauge must be placed away from the cylinder location;

+ Warning signs prohibiting unauthorized personnel from entering the test area;

+ Ensure the gas supply source is safe.

Evaluation of results: The results meet the requirements when the pressure does not decrease during the test period, there is no leakage on the cylinder body or welds, and there is no excessive deformation beyond the specified limit.

đ) For welded cylinders: Evaluate according to point 9.1 TCVN 6292:2013.

e) For cast or seamless cylinders: Evaluate according to point C.4.3 TCVN 6295:1997.

5. Step 5: Volume Expansion Testing

Only applicable to cast or seamless cylinders, proceed according to one of the two methods below:

This applies only to cast and stamped seamless bottles, which shall be carried out in accordance with one of the following two methods:

a) The water jacket method: Fill a bottle with clean water, place the bottle inside a box also filled with water. The total and permanent volume expansion of the bottle is measured by the volume of water displaced from the box due to the bottle's expansion under test pressure and the volume of water that does not return to the box after the pressure is reduced (Assessed according to Point C.5.2.1 TCVN 6295:1997).

b) The non-water jacket method: Measure the volume of water added to a fully water-filled bottle to reach the test pressure and measure the volume of water pushed out of the bottle when reducing the pressure to atmospheric pressure. Measure initially when increasing the water pressure in the bottle to determine the total expansion of the bottle at test pressure, then measure the amount of water pushed out of the bottle, subtract this volume from the total expansion to determine the permanent expansion (Assessed according to Point C.5.2.2 TCVN 6295:1997).

Assessment of results: Assessed according to Point C.5.3 TCVN 6295:1997.

For seamless bottles (capacity from 12 liters to 55 liters), base on the increase in volume or decrease in bottle shell weight to reduce the working pressure of the bottle or remove according to the provisions of Point 4.10 TCVN 6156:1996.

Note: The volume expansion test for cast and seamless bottles is carried out simultaneously with the durability test.

c) Remove and clean the test medium; dry the inside of the bottle.

d) Install the tested valve onto the bottle.

6. Step 6: Pressure tightness test

a) Test medium: Air or inert gas.

b) For welded bottles: Charge compressed air or inert gas into the bottle up to the maximum working pressure or as specified by the manufacturer, maintain this pressure for 01 minute.

c) For cast and seamless bottles: Charge compressed air or inert gas into the bottle up to 50% to 60% of the maximum working pressure, maintain this pressure for 01 minute.

d) Check the tightness of the bottle connections, valve joints, etc., using a soap solution or in a dedicated pressure tightness testing tank. Bottles with leaks must be removed for treatment and retested.

Assessment of results: The result meets requirements when

- For welded bottles: Assessed according to Point 9.2 TCVN 6292:2013;

- For cast and seamless bottles: Assessed according to Point C.6.3 TCVN 6295:1997.

7. Step 7: Gas discharge and vacuum extraction

Bottles that meet the requirements, proceed to discharge all gas, dry the outside of the bottle; extract vacuum and charge protective gas (if required).

8. Step 8: Weighing the bottle shell weight

a) Weigh and determine the shell weight (Assessed according to Point 10.2 TCVN 6292:2013). Check and compare with the shell weight marked by the manufacturer on the bottle;

b) For welded bottles: Assessed according to Point 14.3 TCVN 6294:2007;

c) For cast and seamless bottles: For seamless bottles (capacity from 12 liters to 55 liters) Assessed according to Point 4.10 TCVN 6156:1996.

9. Step 9: Processing the inspection results

a) Prepare the inspection report, list of bottles and bottle lots with complete content according to the model prescribed in the Appendices issued together with this inspection procedure.

b) Approve the inspection report:

The minimum participants required to approve the inspection report must include the following members:

- When inspecting bottles at the inspection station of the inspection organization:

+ The station chief directly performs the bottle inspection;

+ The inspector supervises the inspection process;

+ The team leader directly inspects the bottles.

When the report is approved, these members will sign the report together.

- When inspecting bottles at the facility:

+ Representative of the facility or person authorized by the facility;

+ Person assigned to witness the inspection;

+ Inspector performing the inspection.

When the report is approved, the inspector, the person witnessing the inspection, and the representative of the facility or the person authorized by the facility will sign and stamp (if applicable) the report. The inspection report is prepared in two (02) copies, each party is responsible for keeping one (01) copy.

c) Summarize the inspection results in the lot record (clearly state the inspector's name, date and year of inspection).

d) Stamp the inspection results:

- Stamp the inspection results information on the handle or shoulder of the bottle at the correct size, in a single row in the following order: Inspection organization symbol-month/year of inspection-month/year of next inspection (according to Point 14.4 TCVN 6294:2007 or Point 4.12 TCVN 6156:1996).

Do not stamp over existing data on the handle or shoulder of the bottle.

- For bottles with reduced working pressure, stamp the new data on weight, capacity, and working pressure below the row of inspection result information. The old data must be erased by stamping two diagonal crosses.

- For bottles containing gas charged as provided in Clause 1 of Article 6 of this inspection procedure, do not stamp the inspection results, only perform stamping at the next inspection.

f) Bottles removed must have their threads on the neck damaged or holes drilled in the body of the bottle to prevent the possibility of mistakenly refilling the bottle with gas. Apply the removal method according to Section 15 TCVN 6294:2007 for carbon steel gas bottles or Section 10 TCVN 6871:2007 for acetylene gas bottles.

g) Certify the inspection results: When the bottles pass the technical safety requirements, the inspection organization issues a certificate of inspection results for the bottles or the entire lot within five working days from the date of approving the inspection report at the facility.

h) When the bottles or lot of bottles do not meet the specified requirements, follow Points a, b, and c of Clause 9 of this Article and only issue the facility an inspection report clearly stating the reasons why the inspected bottles or lot did not meet the requirements.

i) Coordinate with the facility to organize the disposal of bottles removed according to Point f of Clause 9 of this Article. Records of removed bottles must be kept at the inspection organization; simultaneously send the inspection report and notification to the local labor management authority where the inspection station is located.

Article 9. Period of Technical Safety Inspection

1. The period for regular technical safety inspection is 05 (five) years.

2. For cylinders that have been in use for over 20 (twenty) years and cylinders containing metal-corrosive gases such as Chlorine, Hydrogen Sulfide, Methyl Chloride, Phosphine, Sulfuric Acid, Hydrogen Chloride, the period for regular technical safety inspection is 02 (two) years.

3. For cylinders containing metal-corrosive gases such as Chlorine, Hydrogen Sulfide, Methyl Chloride, Phosphine, Sulfuric Acid, Hydrogen Chloride that have been in use for over 20 (twenty) years, the period for regular technical safety inspection is 01 (one) year.

4. In cases where the manufacturer specifies or the facility requests a shorter period for regular technical safety inspection, it shall be carried out according to the manufacturer's regulations and the facility's requirements.

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

6. When the period for technical safety inspection is specified in national technical standards, it shall be implemented according to the provisions of those standards.

Appendix 01

MODEL INSPECTION REPORT FOR TECHNICAL SAFETY OF CYLINDERS CONTAINING INDUSTRIAL GASES

TECHNICAL SAFETY INSPECTION REPORT FOR CYLINDERS CONTAINING INDUSTRIAL GASES

Number: …

Based on the Technical Inspection Procedure for Gas Cylinders number QTKĐ :06- 2021/BLĐTBXH issued together with Circular number …/2021/TT-BLĐTBXH dated ... month ... year 2021 of the Ministry of Labor, Invalids and Social Affairs.

We include:

Representatives of the inspection organization:

1…  Inspector number: …

2 …Inspector number: …

Belonging to the inspection organization: …

Registration number of the inspection organization: …

Participants witnessing the inspection and approving the inspection report:

Inspection was conducted on (name of equipment): …

Owned/managed by (name of organization/person owning/managing the cylinder): …

.........................................................................................................

Address (main office of the facility): …

Installation address (location): …

I - BASIC DATA OF THE CYLINDER

- Name and address of the manufacturer: …

- Month, year of manufacture: …

- Batch number of the cylinder: …

- Quantity and list of sample cylinders inspected: …

- Brand name stamped on the cylinder: …

- Working pressure: …bar Test pressure: …bar.

- Capacity: …liters Tare weight of the cylinder: …kg.

- Purpose: …

- Previous inspection report number (if applicable): date: …by (name of inspection organization): …conducted.

II - INSPECTION METHOD

Imported drugs when importing □     Regular □     Irregular □

- Reason for irregular inspection (if applicable): …

III - CONTENT OF INSPECTION

1. Checking documentation and history:

RESULT EVALUATION:

- Remarks: …

- Evaluation result: Complete □ Incomplete □

2. External technical inspection

- Remarks: …

............................................................................................................

- Technical parameters marked on the cylinder: …

- Defects and deformations: …

- Evaluation result: Passed □ Failed □

3. Internal technical inspection

- Remarks: …

..............................................................................................................

- Sealability of the valve and safety device (if present) of the cylinder: …

- Condition of the metal surface and welds (not applicable for acetylene dissolved cylinders): …

- Condition of the porous material (for acetylene dissolved cylinders): …

- Evaluation result: Passed □ Failed □

4. Testing:

- Evaluation result: Passed □ Failed □

IV - CONCLUSION AND RECOMMENDATIONS

1. Batch (number of cylinders) inspected has the result: Passed □ Failed □

2. Has been marked with the inspection symbol at the location: …

3. Working pressure: …bar.

4. Recommendations: …

5. Time to implement recommendations: …

V - INSPECTION PERIOD

Regular inspection on day …month…year …

Report was prepared on day …month…year …

At (clearly indicate the location of the inspection): …

1- In case of inspection at the inspection organization's station:

Appendix 02

LIST SAMPLE CYLINDER INSPECTED 

Batch of cylinders:

Number of cylinders:

Manufacturing number: From …to …

Using unit (management):

(Attached to the inspection report or Certificate of Inspection number: …, date...month…year…)

Appendix 03

LIST OF CYLINDERS NOT IN THE BATCH (OR LIST OF BATCH CYLINDERS) 

Batch of cylinders:

Number of cylinders not in the batch:

Using unit (management):

(Attached to the inspection report or Certificate of Inspection number: …, date...month…year…)

Note:

+ When the batch of cylinders has consecutive manufacturing numbers and the number of cylinders not in the batch is small (due to some cylinders being taken out by the manufacturer for tensile testing, destructive testing, etc.), then "LIST OF CYLINDERS NOT IN THE BATCH" should be noted, if the batch of cylinders does not have consecutive manufacturing numbers, then "LIST OF BATCH CYLINDERS" should be noted and all cylinder numbers in the batch must be listed.

+ When the number of cylinders is small, they can be directly recorded in the report without needing an attached list.

Note: This list cannot be erased or altered and must be stamped or glued.