Circular No. 50/2016/TT-BLDTBXH Issuing National Technical Regulations for Automatic Filters Used in Welding Masks

CIRCULAR

Issuing National Technical Regulations on

concerning Automatic Filters Used in Welding Masks 

Pursuant to the Labor Safety and Health Law No. 84/2015/QH13 dated June 25, 2015;

Pursuant to Decree No. 39/2016/NĐ-CP dated May 15, 2016 of the Government detailing the implementation of certain provisions of the Labor Safety and Health Law;

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;Director of the General Department of Vocational Education;

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

The Minister of Labor, Invalids and Social Affairs issues this Circular on National Technical Regulations for Automatic Filters Used in Welding Masks.

1. Organizations and individuals producing, importing, distributing, installing, using, repairing, maintaining, and servicing elevators shall be responsible for complying with the regulations set forth in the standard issued together with this Circular.

This Circular promulgates National Technical Regulations for Automatic Filters Used in Welding Masks.

Code: QCVN 28:2016/BLDTBXH.

Article 2. Implementation

1. Organizations and individuals producing, importing, supplying, and using automatic filters used in welding masks shall be responsible for complying with the regulations set forth in the standards attached to this Circular.

2. Organizations conducting conformity certification for automatic filters used in welding masks must comply with the regulations set forth in the standards attached to this Circular.

3. Ministries, ministerial-level agencies, government-attached agencies, provincial People's Committees under central cities, and other related organizations and individuals are responsible for implementing this Circular.

Article 3. Effectiveness

1. This Circular takes effect from August 1, 2017.

2. In the course of implementation, if there are any difficulties, please report them to the Ministry of Labor, Invalids and Social Affairs for study and resolution./.

SOCIALIST REPUBLIC OF VIET NAM

QCVN 28:2016/BLDTBXH

 

NATIONAL TECHNICAL REGULATION FOR AUTOMATIC FILTERS USED IN WELDING MASKS

HANOI - 2016

 

QCVN 28:2016/BLDTBXH was compiled by the Department of Occupational Safety and Health and issued by the Ministry of Labor, Invalids and Social Affairs pursuant to Circular No. 50/2016/TT-BLDTBXH dated December 28, 2016, following the review comments of the Ministry of Science and Technology.

Foreword

This standard sets out safety requirements for automatic filters, including:

NATIONAL TECHNICAL REGULATION FOR AUTOMATIC FILTERS USED IN WELDING MASKS

HANOI - 2016

Chapter 1. GENERAL PROVISIONS

1.1. Scope of Application

1.1.1. Automatic filters that reduce light transmission coefficients lower than those created by arc radiation (filters with variable darkness levels) used in welding masks.

1.1.2. Automatic filters equipped for personal protective equipment for welders and fixed to devices.

Hereinafter referred to collectively as automatic filters.

1.2.1. Organizations and individuals producing, importing, supplying, circulating, and using automatic filters.

1.2. Applicability

1.2.2. State management agencies and other related organizations and individuals.

1.3. Terms and Definitions

1.3.1. Automatic filters used in welding masks

Automatic filters used in welding masks have the function of changing the shade number scale from a lower value (lighter shade) to a higher value (darker shade) when arc radiation appears, including:

1.3.1.1. Manual setting automatic filters

Manual setting automatic filters change the shade number scale from a lower value (lighter shade) to a higher value (darker shade) based on user settings during arc welding.

1.3.1.2. Automatic setting automatic filters

Automatic setting filters adjust the shade number scale depending on the intensity of arc radiation.

1.3.2. Brightness state shade number

The brightness state shade number corresponds to the maximum value of the light transmission coefficient τ1 specified in Figure 1, Section 3.2 of Standard EN 379:2003 Personal Eye Protection - Automatic Welding Filters (Personal eye-protection - Automatic welding filters).

1.3.3. Darkness state shade number

The darkness state shade number corresponds to the light transmission coefficient of the filter determined after arc radiation occurs.

1.3.4. Maximum darkness state shade number

The maximum darkness state shade number must correspond to the light transmission coefficient of the automatic filter.

1.3.5. Transition time

The transition time of the automatic filter is determined by the integral formula specified in Section 3.5 of EN 379:2003.

1.3.6. Limited filter

A filter with a low range of spectral coefficients (threshold range) accompanied by a high range of spectral coefficients (wide range) or vice versa.

1.3.7. Viewing area

The viewing area is the defined space for the welding mask lens allowing the user to observe activities and operations while meeting the preset darkness requirements.

Automatic filters must comply with the requirements listed in Table 1. These requirements must meet the highest possible shade number and be adjustable both manually (including manual fine-tuning) and automatically.

2. TECHNICAL PROVISIONS

2.1. General Requirements

Table 1. General Requirements

Characteristics

During testing according to Section 5.1 of Standard EN 379:2003, the automatic filter must not exceed 9 brightness shade numbers (lighter shade) compared to the darkest shade number (darkest shade).

2.3. Light Transmission Coefficient

2.3.1. The minimum light transmission coefficient at the bright state (lighter shade) is 0.16% when measured at temperature ranges (-5 ± 2) °C and (55 ± 2) °C.

2.3.2. The requirements for the light transmission coefficient specified in Table 1 of EN 379:2003 apply to both the bright state (lighter shade) and dark state (darker shade). Measurements are taken at both temperature ranges (-5 ± 2) °C.⁰2.3.3. The ultraviolet light transmission coefficient and the average infrared light transmission coefficient are specified in Table 1 of EN 169:2001, and the additional requirements from (a) to (d) of Section 5.2 of EN 169:2002 for the darkest shade number (darkest shade) must also be applied to other states. Measurements must be conducted at a temperature of (23 ± 5) °C.⁰C.

2.3.4. For filters with automatically adjustable shade numbers, the setting of the darkest shade number must meet the following requirements:₁1. Inspection_{For coal-fired thermal power plants where the enterprise holds 100% of the registered capital and uses 100% of its own capital to invest in the project approved by the competent authority, E is determined as 100%;}, and organize credit institutions, foreign bank branches are responsible for organizing the implementation of this Circular.₂a) The darkest shade number N(E) depends on the illuminance E as follows:⁰2.3.3. The ultraviolet light transmission coefficient and the average infrared light transmission coefficient are specified in Table 1 of EN 169:2001, and the additional requirements from (a) to (d) of Section 5.2 of EN 169:2002 for the darkest shade number (darkest shade) must also be applied to other states. Measurements must be conducted at a temperature of (23 ± 5) °C.⁰C.

N(E) = 2.93 + 2.25 log(E / lux)⁰C.

Some values calculated from this formula are provided in Table 2 within the range of shade numbers between 8 and 14.

Table 2. Darkest Shade Numbers_vDark Shade Number_v Shade Number N Brightness/Lux_vb) The shade number based on the illuminance on the front surface of the filter lens must not deviate more than ±1 shade number calculated from the formula in point (a)._v c) The light transmission coefficient range of the filter must be limited by design not to exceed the darkest shade number (darkest shade) specified by the manufacturer.

d) Ensure the provision of a manual adjustment mechanism, allowing adjustment of the automatically adjustable shade number by ±1 shade number. Adjustment can be tested at both maximum and minimum levels.

Table 2. Scale Number Maximum

b) The scale number must be set according to the illumination level on the front surface of the filter glass and shall not deviate more than ± 1 scale number as calculated in the formula at point (a).

c) The range of light transmission coefficient of the filter must be limited according to the design and shall not exceed the maximum darkest scale number specified by the manufacturer.

d) Ensure the provision of a manual adjustment mechanism that allows for automatic scale number adjustment within ± 1 scale number. The adjustment can be tested at both maximum and minimum levels.

e) When testing with a light intensity level twice that specified at point (a) for the darkest scale (darkest density), the transmission factor must comply with the scale number as specified by the manufacturer.

2.4. Variation of Transmission Factor

When measured according to Sections 7.1, 7.2 of EN 167:2001 at a temperature of (23±5) °C, the values P1, P2, P3 of the filter with variable transmission must not exceed the values prescribed in Table 3 for the designated grade. This requirement applies to both bright and dark states.⁰Table 3. Grading of Filter Glasses According to the Maximum Values of P1, P2, P3 as Specified in 4.3.3 of EN 379:2003

Maximum value of P

The scale transition time must meet Section 2.5.1 or Section 2.5.2 of this Standard for the darkest state (darkest shade).

2.5.1. The scale transition time must comply with Section 5.2 of the EN 379:2003 standard at a temperature of (-5 ± 2) °C. The scale transition time specified in Table 4 must not exceed both temperatures mentioned above.

2.5.2. The scale transition time must comply with Section 5.2 of the EN 379:2003 standard at a temperature of (10 ± 2) °C. The scale transition time specified in Table 4 must not exceed both temperatures mentioned above.⁰2.3.3. The ultraviolet light transmission coefficient and the average infrared light transmission coefficient are specified in Table 1 of EN 169:2001, and the additional requirements from (a) to (d) of Section 5.2 of EN 169:2002 for the darkest shade number (darkest shade) must also be applied to other states. Measurements must be conducted at a temperature of (23 ± 5) °C.⁰2.6. Adjustable Darkest (Shade) Scale

When equipped with a manual adjustment mechanism for the darkest (shade) scale, the manual adjustment must meet the following requirements:⁰2.3.3. The ultraviolet light transmission coefficient and the average infrared light transmission coefficient are specified in Table 1 of EN 169:2001, and the additional requirements from (a) to (d) of Section 5.2 of EN 169:2002 for the darkest shade number (darkest shade) must also be applied to other states. Measurements must be conducted at a temperature of (23 ± 5) °C.⁰2.6.1. There must be a scale indicator for each manual adjustment position.

2.6.2. With an illuminance level of (10

) lux on the surface of the filter, the darkest (shade) scale state must not deviate more than ±1 from the set scale.

2.6.3. If the adjustment range exceeds 5, it must be divided into two sub-ranges with separate manual adjustment devices. Each manual adjustment device can only adjust up to 5 scale points. In the case of an automatic filter with a manual adjustment device as specified in point e of Section 4.3.2.5 of EN 379:2003, the total scale range must not exceed 7 (including tolerance as specified in point b of Section 4.3.5 and point e of Section 4.3.2.5 of EN 379:2003).

2.7. Light Scattering⁴±10³The light scattering value is measured according to one of the methods specified in Section 4 of EN 167:2001.

The maximum value of the luminous flux reduction coefficient in the darkest (shade) or slightly bright (slightly shaded) state to determine the light scattering grade of the filter as specified in Table 4.

Table 4. Grading of Light Scattering

Light scattering degree

Maximum value of the luminous flux reduction coefficient (cd/m

)/lux

The minimum size of the field of view when attached to equipment must be 90 mm horizontally and 35 mm vertically.

2.10. Test Methods

Power Interruption Test

Must comply with Section 5.1 of EN 379:2003

Step Scale Transition Time Measurement

2.10.1. Must comply with Section 5.2 of EN 379:2003

Setting the Scale of the Filter with Automatic Scale Adjustment

2.10.2. Must comply with Section 5.3 of EN 379:2003

Spectral Sensitivity of the Filter with Automatic Scale Adjustment Device

2.10.3. Use the monochromatic radiation method specified in Section 5.4.2 of EN 379:2003 or the method using threshold filters specified in Section 5.4.3 of EN 379:2003. Measurements may be conducted at a temperature of (23±5) °C.

Place the light source according to the set scale number and sample so that the measurement surface receives the light beam through the filter with the illuminance within the automatically set scale range.

2.10.4. Angle Dependence of Transmission Factor

Conducted according to the provisions of Section 5.5 of EN 379:2003⁰C.

Sample Testing

2.10.5Conducted according to the provisions of Section 5.6 of EN 379:2003

2.11. Labeling

2.10.62.11.1. General Requirements:

Labels must comply with Section 9 of EN 166:2001 along with additional information that must be permanently marked and clearly visible on the equipment.

2.11.2. Automatic Filters and Automatic Filters with Manual Adjustment Mechanism for the Darkest Scale.

Comply with the provisions of Section 6.2 of EN 379:2003

2.11.3. Filters with Automatically Adjustable Scale.

The brightest and darkest (shade) scale states separated by a slash (/) are used instead of a single scale number. The darkest scale state is marked separately with the symbol “<”. In cases where the filters have manual compensation adjustment mechanisms, "M" is added after the darkest scale state number. Optical grades must follow the grades of light scattering, variation of transmission factor grade, and angle dependence of transmission factor grade, which are separated by slashes.

In cases where the requirements of Section 2.5.1 of this Standard are met, labeling is not required.

In cases where the requirements of Section 2.5.2 of this Standard are met but do not satisfy the requirements of Section 2.5.1 of this Standard, a warning label stating "Do Not Use Below 10

Manufacturer Information

Each filter must come with usage instructions provided by the manufacturer along with the following additional information:

2.12.1. Suitable cutting/welding process type;⁰C.

2.12. 2.12.2. Guidance on identifying damage;

2.12.3. Information about the replacement period for the filter or part of the filter;

2.12.4. When the equipment does not meet the test requirements at -5

°C, a warning label stating "Do Not Use Below 10

°C" must be included.

2.12.5. Sensor notifications must be clear;⁰Selection of Automatic Filters⁰Selection of automatic filters according to Appendix A of EN 379:2003.

Domestic Produced Automatic Filters

2.13. Domestic produced automatic filters must be certified and publicly announced in compliance with the relevant laws.

Certification is carried out by conformity assessment organizations designated by the Ministry of Labor, Invalids and Social Affairs.

3. MANAGEMENT PROVISIONS

3.1. Implementation Method: Typical sample testing combined with production process evaluation; monitoring through sampling tests taken at the production site combined with production process evaluation (Method 3 in the Regulation on Public Announcement of Compliance with Standards and Technical Regulations issued together with Circular No. 28/2012/TT-BKHCN dated December 12, 2012 of the Minister of Science and Technology). domestically produced

Domestically produced filters must be certified and declared compliant in accordance with the provisions of the law.

Compliance certification shall be carried out by conformity assessment organizations designated by the Ministry of Labor - Invalids and Social Affairs.

Implementation method: testing of typical samples combined with production process evaluation; monitoring through testing of samples taken from the production site combined with production process evaluation (Method 3 in the Provision on Declaration of Conformity and Method of Conformity Assessment with Technical Standards issued together with Circular No. 28/2012/TT-BKHCN dated December 12, 2012 of the Minister of Science and Technology).

3.2. Implementation Method: Typical sample testing combined with production process evaluation; monitoring through sampling tests taken at the production site combined with production process evaluation (Method 3 in the Regulation on Public Announcement of Compliance with Standards and Technical Regulations issued together with Circular No. 28/2012/TT-BKHCN dated December 12, 2012 of the Minister of Science and Technology). 2. Import procedures shall be carried out in accordance with relevant laws and regulations.

3.2.1. Automatic import filters must be certified for conformity and registered for state inspection of imported goods' quality in accordance with the law.

3.2.2. Conformity certification shall be carried out by organizations designated by the Ministry of Labor, Invalids and Social Affairs to perform such certification or by foreign organizations and individuals recognized to conduct it...

3.2.3. Conformity certification shall be conducted through testing and evaluating batches of products (Method 7 as stipulated in the Regulations on Announcement of Compliance with Technical Standards and Quality Standards and Methods of Evaluating Conformity with Technical Standards issued together with Circular No. 28/2012/TT-BKHCN dated December 12, 2012 of the Minister of Science and Technology).

3.2.4. Imported automatic filters shall be exempt from quality inspection in cases where bilateral or multilateral agreements between competent authorities of the Socialist Republic of Vietnam and exporting countries stipulate that quality inspection is not required upon importation.

3.2.5. Samples of products used solely for display purposes and not directly for workers shall be exempt from import quality inspection, with a maximum quantity of five units.

3.3. Automatic filters provided on the market

3.3.1. Automatic filters provided on the market must bear conformity marks and labeling in accordance with current Vietnamese law.

3.3.2. Corresponding to protective functions, there must be symbols displayed on personal protective equipment. These symbols must be explained in the user manual provided by the manufacturer.

3.3.3. Organizations and individuals providing automatic filters must provide the user manual, storage instructions, and usage inspection guidelines issued by the manufacturer.

3.4. Usage managementImplementation Method: Typical sample testing combined with production process evaluation; monitoring through sampling tests taken at the production site combined with production process evaluation (Method 3 in the Regulation on Public Announcement of Compliance with Standards and Technical Regulations issued together with Circular No. 28/2012/TT-BKHCN dated December 12, 2012 of the Minister of Science and Technology).

3.4.1. Automatic filters must be stored in dry, well-ventilated environments, away from heat sources, and free from harmful solvents, in accordance with the manufacturer's instructions.

3.4.2. Automatic filters must be used for their intended purpose, in accordance with their function, and following the manufacturer's user manual.

3.4.3. Automatic filters must be inspected according to the manufacturer's instructions. They shall not be used if the inspection results do not meet requirements or if they exceed the manufacturer's recommended usage period.

Employers must base their inspection procedures for the functionality of automatic filters on the manufacturer's usage, storage, and inspection guidelines. The inspection guidelines must be communicated to employees and posted in easily accessible locations.

Before using automatic filters, employees must conduct self-inspection according to the posted guidelines at the workplace.

Daily self-inspections when using automatic filters must be monitored and recorded in a log.

4. RESPONSIBILITIES OF ORGANIZATIONS AND INDIVIDUALS

4.1. Organizations and individuals producing, importing, supplying, and using automatic welding filters are responsible for complying with the provisions of this Standard.

4.2. This Standard serves as the basis for inspecting the quality and certifying the conformity of automatic filters.

This Standard serves as the basis for labor inspections and occupational safety and health inspections conducted by state authorities.

Chapter 5. ORGANIZATION OF IMPLEMENTATION

5.1. The Department of Occupational Safety and Health, under the Ministry of Labor, Invalids and Social Affairs, is responsible for coordinating with relevant agencies to guide and organize the implementation of this Standard.

5.2. Local government agencies managing labor affairs have the responsibility to guide, inspect, and monitor compliance with the technical standards set forth in this Standard.

5.3. During implementation, if any issues arise, related agencies, organizations, and individuals must promptly report them to the Ministry of Labor, Invalids and Social Affairs for consideration and resolution./.