Hazardous Area Equipment · Made in UAE Ex Proof Enclosures Explained: Ex eb & Ex ia for Hazardous Areas How increased safety and intrinsic safety enclosures protect people and plant in Zone 1, Zone 2, Zone 21 and Zone 22, and how to specify the right one for your process. IECExATEXDUSTECASIP66SS 316L In oil &…
This will close in 20 seconds
This will close in 20 seconds
How increased safety and intrinsic safety enclosures protect people and plant in Zone 1, Zone 2, Zone 21 and Zone 22, and how to specify the right one for your process.
In oil & gas, petrochemical and process plants across the Gulf, a single spark in the wrong place can be catastrophic. That is why the electrical junction boxes, terminal boxes and control panels installed in flammable environments are not ordinary sheet metal boxes. They are certified Ex proof and Dust Proof enclosures, engineered so that the electrical connections inside can never ignite the gas, vapour or dust around them.
This guide explains how Ex proof enclosures work, the difference between Ex eb increased safety and Ex ia intrinsic safety, how to read the certification marking, and how to choose a size, material and configuration that matches your area classification. It is written for our customers who already rely on KLEEV instrumentation, the teams specifying pressure, temperature, level and flow measurement for hazardous plants.
An Ex proof enclosure is a housing certified to hold electrical terminals, cable connections or control components safely inside an explosive atmosphere. "Ex" is the international shorthand for explosion protection. Unlike a standard IP rated box, this type of enclosure is type tested against a family of standards, the IEC 60079 series, and carries a certificate from a recognised body before it can legally be used in a classified zone.
Two ideas sit at the heart of every certified enclosure. First, the housing must keep out water and dust to a high ingress protection rating, because moisture and conductive dust are themselves ignition risks. Second, the protection concept applied to the internal components must guarantee that no spark or hot surface capable of igniting the surrounding atmosphere can occur, even when something inside fails. KLEEV housings achieve the first with an IP66 rating and a continuous silicone gasket, and the second through the certified protection concepts described below.
"Explosion proof" in everyday speech is an umbrella term. Technically, KLEEV enclosures use Ex eb (increased safety) and Ex ia (intrinsic safety), protection concepts that prevent ignition, rather than containing an internal explosion the way flameproof "Ex d" does.
Every certified enclosure carries a marking string that tells you exactly where it may be installed. Tap each block below to see what it means:
Equipment Group II
Group II covers all surface industries (everything except underground mining, which is Group I). Your refinery, gas plant or grain facility is Group II.
Before you can choose an Ex proof enclosure, the installation area must be classified. Hazardous areas are divided into zones according to how often an explosive atmosphere is present. Gas and vapour use zones 0, 1 and 2; combustible dust uses the parallel zones 20, 21 and 22. This classification, defined in IEC 60079 Part 10, dictates the minimum Equipment Protection Level (EPL) an enclosure must carry.
Continuous. Explosive gas present constantly or for long periods. Needs EPL Ga, typically Ex ia.
Likely. Present in normal operation. EPL Gb, so Ex eb or Ex ib enclosures fit here.
Rare or brief. Present only under fault or short periods. EPL Gc, Ex ec accepted.
Continuous. Dust cloud present constantly, for example inside a silo. Needs EPL Da.
Likely. Dust cloud in normal operation. EPL Db, Ex tb enclosures.
Rare or brief. Dust cloud only occasionally. EPL Dc.
KLEEV Ex proof enclosures are certified II 2GD, category 2 for both gas and dust, which means they are approved for Zone 1, Zone 2, Zone 21 and Zone 22. Getting this match right is the single most important decision in the whole specification: fitting a Zone 2 device into a Zone 1 location is not a paperwork gap, it is a design error with real safety consequences.
KLEEV housings are built around two complementary protection concepts. They are not competitors; most real installations use both, side by side, in the same box.
Increased safety, defined in IEC 60079 Part 7, works by making sure an ignition source can never form in the first place. It applies stricter construction rules than ordinary electrical equipment: larger creepage and clearance distances between live parts, high quality captive terminals that will not vibrate loose, controlled surface temperatures and a minimum ingress rating. There is deliberately no spark producing component inside, no contactor arcing, no switching under load.
This is the natural concept for terminal boxes and junction boxes: the box simply carries power and signal terminations through a hazardous area. Increased safety housings are rated Gb, so they serve Zone 1 and Zone 2 directly.
Intrinsic safety, defined in IEC 60079 Part 11, takes a different route: it limits the electrical energy in the circuit to a level so low that a spark simply cannot carry enough energy to ignite the atmosphere, even under two simultaneous faults. Because it removes the ignition risk entirely, Ex ia is the only concept accepted in Zone 0, and it also covers Zone 1 and Zone 2.
Intrinsic safety is a system concept: a safety barrier, the field cable and the field device all work together. It is the dominant method for instrumentation, the 4 to 20 mA and HART loops from pressure, temperature, level and flow transmitters. An enclosure can house an Ex ia marshalling section, keeping intrinsically safe circuits segregated from increased safety power terminals.
A single KLEEV enclosure can be marked Ex eb ia IIC: increased safety power terminals on one side, an intrinsically safe instrument section on the other, both certified in one housing. That is why the concepts appear together on the nameplate.
The KPE series covers the three jobs an Ex proof enclosure is asked to do on site. Whether you need an empty shell to populate yourself or a fully wired panel, the same certified body is the starting point.
A certified empty housing for you to fit out, with locks (ENL) or bolted fasteners (ENB). Ideal for custom builds and OEM integration.
Enclosure supplied with certified terminal blocks and earth bars, the workhorse junction box for power and signal marshalling.
A ready to mount control station with certified push buttons, switches and indicators for local motor and process control.
All three share the same construction platform, so you move from an empty box to a wired control panel without changing your certification basis. Custom sizes are available too, as long as no dimension is larger than the biggest standard size or smaller than the smallest.
The Gulf combines salt laden coastal air, desert dust, washdown and extreme heat, a brutal test for any enclosure. KLEEV housings answer it with the right materials and a rugged build, so the certification you buy on day one still holds years later.
Bodies are formed from Stainless Steel 316L as standard, with mild, carbon or galvanised steel available where budget or application allows. A continuous silicone gasket seals the door; captive screws with concealed hinges keep everything tamper resistant. Removable gland plates, bottom as standard or on any side, make cable entry planning simple, and an M10 external earth stud plus internal earthing keeps the whole assembly safely bonded. Options such as sunshades, drawing pockets, pad eyes and door stoppers adapt each housing to its exact mounting location.
Any facility with a classified area is a candidate for Ex proof enclosures. Across the region, KLEEV housings protect terminations and controls in the sectors below, often alongside the very instruments the enclosure connects.
Upstream wellheads, gas processing, tank farms and pipeline stations in Zone 1 and Zone 2.
Refineries and chemical plants where solvents and hydrocarbons demand IIC rated protection.
Digesters and pump stations where biogas creates flammable atmospheres.
Platforms and vessels needing 316L corrosion resistance plus Ex certification.
Solvent handling and drying areas classified for both gas and dust.
Combustible dust Zone 21 and 22 areas served by Ex tb IIIC enclosures.
In every one of these settings the enclosure is only as valuable as the signals it carries. A junction box marshalling level and flow transmitters, or a local control panel starting a hazardous area pump, is where measurement and safety meet, which is exactly the intersection KLEEV manufactures for.
Certification is what separates a genuine Ex proof enclosure from a lookalike box. KLEEV enclosures hold three parallel approvals so they can be specified almost anywhere in the world, and released legally inside the UAE:
IECEx is the international certification scheme accepted across most of the world. ATEX is the European framework (Directive 2014/34/EU) required to place equipment on the EU market. ECAS, the Emirates Conformity Assessment Scheme, is the UAE national mark, so the product is compliant for local supply. All three rest on the same technical base: the EN IEC 60079 standards for equipment in explosive atmospheres, plus IEC 60529 for the IP66 rating.
A certificate ties a specific enclosure design to a specific marking. Modifying a certified box on site, such as drilling an extra gland hole or swapping a gasket, can void the certification. Always specify entries and options up front so the "as installed" product still matches its certificate.
Specifying an Ex proof enclosure comes down to five questions: What is the area classification (which zone and gas or dust group)? What temperature class do the substances demand? How many and what size cable entries are needed? What material suits the environment? And is it an empty box, a terminal box or a control panel? Answer those and the KPE part number almost writes itself.
KLEEV uses a logical model code. Build one below by tapping each block to see what it encodes:
KPE: Product family
Kleev Products Enclosure, the base series for every certified enclosure in the range.
The example above, KPE 04 ENB 380 380 200, describes a bolted, empty, 316L stainless enclosure measuring 380 × 380 × 200 mm. Change any block and the specification updates with it. When in doubt, KLEEV's engineering team will translate your area classification drawing into a fully certified part number and cable entry schedule.
No. Flameproof "Ex d" contains an internal explosion within a robust housing. KLEEV enclosures use Ex eb and Ex ia, which prevent ignition rather than containing it. "Ex proof enclosure" is the broad umbrella term for all of these hazardous area housings.
Certified II 2GD, they suit Zone 1 and Zone 2 for gas, and Zone 21 and Zone 22 for dust. For Zone 0, an intrinsically safe (Ex ia) circuit is required.
Cable entries should be specified before manufacture so the certified marking matches the "as installed" product. Removable gland plates make the entry layout flexible, and KLEEV pre drills to your schedule.
Stainless Steel 316L is standard and ideal for coastal, offshore and washdown duty. Mild, carbon or galvanised steel are available where the environment is less aggressive or budget is the priority.
Ex proof enclosures are a small part of a plant's capital cost and an enormous part of its safety case. Get the zone, protection concept, temperature class and material right, and a certified enclosure will quietly protect your people and your process for its full service life. Get any of them wrong, and no amount of instrumentation downstream can make the installation safe.
KLEEV Middle East manufactures IECEx, ATEX and ECAS certified Ex proof enclosures in the UAE, empty enclosures, terminal boxes and local control panels, engineered for the region's toughest hazardous area duty and backed by the same measurement expertise behind every KLEEV instrument.
Send us your area classification drawing or cable schedule. Our engineering team will return a certified part number, cable entry layout and quotation, built and tested in the UAE.
