In oil and gas, petrochemical and chemical installations, cutting pipes and sheets in potentially explosive atmospheres excludes conventional thermal methods and equipment. The use of oxyacetylene flame, angle grinders or other tools that may generate sparks or localized heat requires a specific risk assessment and the adoption of appropriate control measures in classified ATEX zones. Mechanical cold cutting solves this constraint, and GBC machines, in pneumatic and hydraulic versions, are suitable for use in these contexts.

What is an ATEX zone and why does it change everything

ATEX stands for ATmosphere EXplosive. The classification of the zones is established in accordance with Directive 1999/92/EC, transposed in Italy by Legislative Decree 81/2008, Title XI, which requires the employer to assess the risk of explosion and classify workplaces into zones (0, 1, 2 for gases/vapours; 20, 21, 22 for dust). The certification of equipment intended to operate in these areas is instead regulated by Directive 2014/34/EU (ATEX 114), which defines the essential safety requirements for manufacturers.

The zones are classified according to the frequency and duration of the presence of an explosive atmosphere:

• Zone 0 / Zone 20: Explosive atmosphere present continuously or for long periods
• Zone 1 / Zone 21: Explosive atmosphere occasionally present under normal conditions
• Zone 2 / Zone 22: Explosive atmosphere present rarely and for a short duration

Each zone requires machines and tools certified for the corresponding group and category, with a temperature class appropriate to the substances present in the area.

Why flame cutting is to be avoided in the ATEX area

The oxyacetylene flame reaches temperatures above 3,000 degrees C and generates sparks capable of igniting an explosive atmosphere. Angle grinders produce glowing projections that can project up to several meters away, depending on the material and working angle. Plasma cutting introduces a high-energy electric arc. Any of these ignition sources, in a classified ATEX zone, constitutes an unacceptable risk.

Cold cutting significantly reduces ignition sources because the process is predominantly mechanical: the tool removes material for cutting or milling without generating significant heat, without arcing and without incandescent projections.

Cold cutting machines for ATEX areas: what the certification means

Machinery intended to operate in an explosive atmosphere must comply with the applicable requirements of Directive 2014/34/EU and bear the required Ex marking, with group, category and additional technical information relevant to the type of equipment.

For example, a marking such as II 2G Ex h IIB T4 indicates a group II, category 2 gas equipment, with protection type ‘h’, suitable for gas group IIB and temperature class T4, according to the marking applicable to the specific product.

The temperature class must be chosen according to the auto-ignition temperature of the substance present; It is not possible to indicate a minimum value valid for all hydrocarbons, because the data vary from substance to substance.

Operational advantages of cold cutting in the Ex environment

Compared to shutdown to carry out flame work in a safe area, cold cutting can reduce the need for extended shutdowns or complete remediation. However, operation remains subject to risk assessment, plant procedures and suitability of the equipment.

The operational advantages:

• No ignition source generated during cutting
• Precise cutting with tight tolerances, without thermal deformation of the material
• Integrated bevel in a single pass on many GBC machines
• Confined space operation and limited access
• Reduced downtime compared to methods requiring remediation

The absence of a Heat Affected Zone (HAZ) is particularly relevant for sensitive materials such as duplex steel, Inconel, and nickel alloys, where heat changes metallurgical properties and can impair subsequent weldability.

Typical applications in classified environments

GBC cold cutting machines are used in the following situations in the ATEX area:

• Refineries and petrochemical plants: replacement of in-line pipe sections during scheduled or emergency maintenance
• LNG storage terminals: cutting and beveling of cryogenic tubes made of stainless steel and special alloys
• Offshore platforms: cutting and beveling pipelines in offshore modules and deck equipment, where environmental conditions and limited access make flame impractical
• Chemical and pharmaceutical plants: Cutting pipes made of stainless steel, duplex or special materials with surface purity requirements
• Power plants: interventions on steam circuits and high-pressure pipes in classified areas

How to Choose Cold Cutting Machine for ATEX Zone

The choice of machine depends on four main parameters:

1. Pipe diameter and thickness

GBC offers machines for diameters from 10 mm up to over 2,000 mm. Identifying the range of diameters present in the implant is the first step.

2. ATEX category required

The category depends on the classified zone: category 1 for Zone 0/20, category 2 for Zone 1/21, category 3 for Zone 2/22. Most maintenance applications on operating systems require category 2.

3. Power supply available

For use in classified areas, Ex certification is possible for pneumatic and hydraulic versions: machines with electric power supply are not certifiable for ATEX use. Pneumatic power is also preferred in high-risk areas because it eliminates any risk of arc flash.

4. Operation required

Pure cut, bevel, or combination of cut and bevel in one pass. Some GBC machines integrate both functions, reducing setup time and the number of equipment to be brought to the area.

Always check the safety data sheet of the substance in your area. Class T3 is not sufficient in all cases: the choice of the thermal class must be made on the basis of the autoignition temperature of the substance actually present.

GBC Industrial Tools machines for ATEX environments

GBC machines for cold cutting and beveling of pipes and sheets adopt, in the pneumatic and hydraulic versions, the technology naturally suitable for classified environments: purely mechanical process, no electric arc, no incandescent projection. These versions can be Ex certified under Directive 2014/34/EU upon request.

GBC’s technical team supports the customer in selecting the correct machine according to the classified area, the working diameter, the available feed and the substance present.

Contact us for a quote or technical advice.