Environment and Safety Rules in Sandblasting Facilities

What is Sandblasting?

In corrosion control, there are procedures to extend the life of metal surfaces and to achieve the desired quality coating. Surface quality is largely dependent on surface preparation before coating. The most commonly used and most effective method of removing corrosion effects is coating the surface with materials resistant to external factors. Surface preparation before these coatings is the basis of coating quality. Sandblasting is a method used to provide the roughness required for paint adhesion to the surface, to homogenize the surface, and to clean rust, lime, oil and paint residue from the metal surface. In application, blasting is the process of impacting the surface with granules using high-pressure air. During this impingement, the granule abrades the surface at the micron level while cleaning it. Special pressure blasting pots are used for sandblasting application. The degree of surface roughness desired depends on the type, size, shape and application pressure of the abrasive granule used. The blasting process should be performed in special facilities designed for sandblasting and these facilities must be installed in accordance with Environmental Health Standards and Safety Rules.

Sandblasting Facilities Environmental Health Standards

To obtain a work permit, established sandblasting facilities must be designed in accordance with environmental regulations. The goal of the Environment Regulation is to ensure that facility operations do not damage the environment, to ensure emission limit values are met, to control air quality and to control mass flow.

Emission:

Air pollutants emitted to the atmosphere from a facility as a result of fuel firing and similar processes; synthesis, decomposition, evaporation and similar processes; agglomerate of material, separation, material handling and other mechanical processes. Dust emission values specified in the industrial air pollution control regulation must be provided in sandblasting facilities. To obtain emission permits, dust is sent to the dust collector unit where it is filtered and discharged from the chimney. Chimney height from the roof is important for meeting emission values and regulatory provisions. Chimney heights are one of the definitive requirements that must be met to obtain necessary permits. The dust emission limit value specified in the regulation is 20 mg/Nm³. The dust released during the blasting process is quite intensive. Suitable filtration is very important for occupational health and safety, for operating efficiency of the factory environment and for compliance with Ministry of Environment standards. Special filter units are used to meet emission values. Dusty air is brought to the filter by air ducts designed to suitable diameter and thickness. Air filtered through is discharged from the chimney via a fan. In filter design and fan selection, facility volume, the number of sandblasting operators in the facility, location of dust suction points and similar criteria should be considered.

Sandblasting Facilities Safety Precautions and Employee Health

Sandblasting in closed areas should be performed in facilities with sufficient lighting, appropriate security measures and adequate space for processing. Lighting: The lighting level should be selected to provide operation quality and correct angle of view for the operator in sandblasting facilities. Sandblasting in darker areas not only affects surface quality but also presents a hazard to operator safety.

Equipment Used and Protective Measures; Pressure Sandblasting Pot

Sandblasting pots used for blasting applications operate at high pressure. Average pressure at the nozzle outlet is 7.5 bar. Sandblasting pots to be used must undergo hydrostatic tests with documented results and must have a certificate of conformity to the AT Pressure Equipment Directive. High-pressure sandblasted granules present serious danger if misused. To prevent possible accidents, sandblasting pots must be automatically controlled via a deadman handle.

If operators fall for any reason or the nozzle escapes their hand, the system automatically stops blasting, preventing injury. Blasting Hose:

Sandblasting is performed with special hoses resistant to high pressure. Hoses used in the sandblasting process must be certified and comply with TS 5928 EN ISO 3861 standards. Sandblasting hoses must be secured with safety cables.

Blasting Nozzle:

Blasting nozzles are manufactured from various special explosion-proof materials. Nozzle quality and standards compliance are of major importance in preventing occupational accidents.

Operator Blast Helmet & Blast Suit:

The blasting operator must wear a protective blast helmet and suit specifically designed for sandblasting. The blast helmet and suit prevent injury to the operator from granules expelled from the pressurized blasting pot. The blasting helmet must be certified to EN 14594 standards.

Breathing Air Filter Unit:

One of the most important health hazards in sandblasting facilities is airborne dust. In addition to the filtration system in the sandblasting facility, the operator must use a fresh air supply unit while present in the facility. Clean air units are typically supplied from a compressor. The fresh air unit passes air from the compressor through an activated charcoal filter and delivers fresh air to the operator's helmet. Çiğdem Arslan Project Director Sandblasting & Painting Systems Alfatechnic Makina San. ve Dış Tic. Ltd. Şti.