IEC 60079-26 separation elements: scope and current status
The official IEC 60079-26:2021 catalogue page identifies Edition 4.0, published on February 25, 2021, with a stability date of 2027. The July 2026 IEC 60079 series listing continues to include it.
IEC describes equipment that contains parts with different EPLs and a separation element. The equipment is mounted across a boundary where different EPLs are required. The public scope gives three boundary examples:
- between different gas hazardous areas;
- between different dust hazardous areas;
- between a gas hazardous area and an adjacent dust hazardous area.
This is an equipment-construction standard, not a general instruction to place one device on each side of a zone boundary. It supplements and modifies IEC 60079-0 for its scope.
What is a separation element?
For a buyer, a separation element is a controlled part of the complete equipment construction that maintains separation between parts exposed to different hazardous-area requirements. Its identity, material, geometry, interfaces and location belong to the assessed equipment.
The catalogue scope does not authorize a universal part or field-made barrier. A flange, wall, seal, shaft interface or process connection that appears to separate two spaces is not automatically an IEC 60079-26 separation element. The exact construction and its evidence determine the claim.
| Project question | Evidence to request | Unsafe shortcut |
|---|---|---|
| Which boundary is crossed? | Area-classification drawing and equipment installation location | Naming only the higher-risk side |
| Which parts require which EPL? | Controlled equipment drawing and marking logic | Assuming one marking applies identically to every part |
| What performs the separation? | Defined element, material, dimensions, interfaces and assessment records | Calling any physical wall a separation element |
| What protection does the complete equipment claim? | Certificate or other conformity records, schedule, marking and instructions | Combining independent product labels |
| How is the construction preserved? | Installation, inspection, maintenance and replacement instructions | Relying on appearance after installation |
Different EPLs across one equipment boundary
An Equipment Protection Level expresses the level of protection assigned to equipment for its intended explosive atmosphere. The MMAIATEX EPL guide explains Ga, Gb, Gc, Da, Db and Dc. IEC 60079-26 addresses a more specific question: how a single equipment construction is assessed when its parts encounter different EPL requirements across a boundary.
The buyer should map the physical installation to the equipment documentation. Confirm which part is on each side, which explosive atmosphere is relevant, which EPL applies and where the separation element sits. If the installation position changes, the evidence may no longer match.
Do not treat a zone boundary as a neat line without project evidence. Area classification, release sources, ventilation, process openings and mounting belong to competent project review. The equipment standard does not classify the site.
Electrical and non-electrical separation elements
IEC states that separation elements are considered for both electrical and non-electrical equipment. If mechanical energy can be transformed into a potential ignition source, the public scope calls for an additional ignition-hazard assessment in accordance with ISO 80079-36 and appropriate measures.
The MMAIATEX guide to ISO 80079-36 non-electrical Ex equipment explains that assessment route. The need is not removed because the equipment also has electrical markings. Shafts, motion, friction, impact and other mechanical energy sources must be addressed by the applicable design and assessment, not inferred from a photograph or enclosure material.
Combined protection does not mean two products equal Ga
IEC 60079-26 also specifies requirements for combining two Types of Protection, each with EPL Gb, to achieve EPL Ga. The words Types of Protection and the complete equipment context are essential.
This route does not allow a buyer to select two unrelated Gb-certified products and declare the result Ga. The combination must be an assessed construction under IEC 60079-26, the relevant protection standards and general requirements. Interfaces, faults, marking, documentation and certificate conditions belong to the actual design.
Use this stop test:
- Is there one identified complete equipment construction?
- Are both Types of Protection and their interaction defined in controlled documents?
- Does the conformity evidence expressly cover the Ga claim for that construction?
- Does the offered model and revision match the assessed version?
- Are special conditions and installation instructions available?
A no or an uncertain answer means the Ga conclusion has not been established.
Six records a buyer should connect
1. Area-classification basis
Record the explosive atmospheres, zone or zones, required EPLs, groups, temperature limits, ambient conditions and boundary location. Identify who approved the classification and which drawing revision applies.
2. Complete equipment identity
Match legal manufacturer, model, suffix, options and revision across the quotation, nameplate, certificate or other conformity record, schedule, drawings and instructions. The MMAIATEX Ex marking guide can help structure the comparison.
3. Separation-element definition
Request the controlled drawing references that identify the element, permitted dimensions, material, interfaces, orientation and mounting position. Do not request protected design secrets that are unnecessary for procurement, but ensure the conformity and installation records clearly identify the approved construction.
4. Protection and EPL evidence
Trace each claimed EPL and Type of Protection to the complete equipment documents. Where combined protection is used for Ga, require evidence that the combination itself is within scope. The IECEx and ATEX verification guide explains how to match certificate identity, issue, status, schedule and conditions.
5. Installation and lifecycle instructions
Obtain requirements for location, orientation, fastening, process connection, wiring, environmental limits, initial inspection, routine inspection, maintenance and replacement. A change to the element or mounting can affect the protection basis even when the equipment still functions.
6. Change-control record
Freeze the accepted drawing and model references in the purchase file. Review substitutions, process changes, new substances, altered boundaries, mechanical modifications, repair and replacement before implementation. The Ex s special protection guide describes a different protection route and should not be used as a substitute for Part 26 evidence.
Marking and document questions for the supplier
Ask the supplier to answer these questions against the offered configuration:
- Which part of the equipment is exposed to each classified area?
- Which EPL and Type of Protection apply to each relevant part?
- What is the separation element and where may it be mounted?
- Does the evidence cover electrical, non-electrical or both aspects?
- Does the design use the combined-protection route for EPL Ga?
- Which exact certificate or other conformity records cover the complete equipment?
- Which schedules, conditions, drawings and instructions control installation?
- What inspection and replacement rules preserve the separation?
The IECEx test report form for IEC 60079-26 is associated with the standard edition, but a blank or referenced test report form is not a product certificate.
Current MMAIATEX certification status
MMAIATEX is the public brand of MMAIATEX Explosion-proof Technology (Zhejiang) Co., Ltd. The public About page states that ATEX, IECEx and CCC certification work is in progress. This article, a product image, a boundary drawing or a standards reference does not prove that a particular MMAIATEX model or complete construction is certified or suitable. Verify exact marking, current documents, scope, conditions and destination requirements.
Safety and legal disclaimer
This article is general technical and procurement information. It is not an area classification, separation-element design, ignition-hazard assessment, certificate, installation approval or legal opinion. An incorrect boundary construction can expose equipment to conditions beyond its assessed protection and can create fire or explosion risk. Use current licensed standards, exact equipment documents, applicable law and competent professionals. Stop work if the boundary, EPL, equipment identity, separation element or combined-protection evidence is uncertain.
Contact MMAIATEX for a document request
Send the area-classification drawing, required EPLs, gas or dust groups, proposed equipment model, boundary arrangement, ambient and process conditions, destination and required document list so MMAIATEX can organise available product information for competent review.