ATEX Pressurized Room (Ex P)

The Ex-M Pressurised Container, also known as an ATEX pressurised room or Ex-p enclosure, is a custom-engineered explosion proof container that creates a safe area inside an ATEX Zone 2 hazardous area. The solution is designed and assessed to IEC EN 60079-13:2010 with type of protection pz, and each pressurised room is built around your specific equipment, zone classification, gas group and site conditions. Every unit is delivered with a full Technical Construction File demonstrating compliance with the standard.

Rather than sourcing an ATEX-certified version of every item that needs to sit in your hazardous area, an Ex-p room takes the hazard away. Clean air drawn from a non-hazardous area is continuously blown into the pressurised container to maintain overpressure, which physically prevents the surrounding explosive atmosphere from entering. Standard non-Ex equipment, from diesel generators and gas compressors to HMI stations, switchgear and analyser skids, can then run safely inside the enclosure using the off-the-shelf products you already know.

How a Pressurised Room Creates a Safe Area

An external ventilation unit continuously supplies clean air from a non-hazardous area, creating positive overpressure inside the Ex-p enclosure. Pressure-differential and air-flow sensors monitor the pressurisation system in real time. Before each start-up an automatic purge cycle replaces the internal volume multiple times to clear any residual explosive atmosphere. Per EN 60079-13 a minimum of five air changes per hour is maintained; the actual ventilation capacity is sized to the container volume and to the internal heat load of the equipment housed inside.

If pressurisation is lost, the control system automatically shuts down ignition-capable equipment, warns personnel via alarm lights and sirens (both inside and outside the pressurised room), and closes the shut-off valve on any flammable substance supply. Doors are self-closing and latch against the working pressure differential, with door switches monitoring position throughout operation.

Typical Equipment Housed Inside an Ex-p Container

• Power and drives: diesel generators, gas engines, gas turbines, variable frequency drives, soft starters, transformers, switchgear, motor control centres (MCCs)
• Rotating equipment: gas compressors, pumps, blowers, fans
• Control and IT: HMI and operator workstations, PLC and control cabinets, SCADA and telecom cabinets, server racks and industrial PCs
• Process instrumentation: gas analyser skids, sampling systems, metering and calibration equipment
• Utility and support: UPS systems, battery banks, laboratory and workshop equipment

Unique Options

• Protection type variants: pz standard for ATEX Zone 2. Types pv, px or py available on request
• Custom dimensions and footprint, engineered around the specific equipment housed inside the pressurised room
• Marine upgrade: corrosion-protection coating and AISI 316 stainless steel fasteners for offshore ATEX containers
• Offshore corrosion resistance treatment on all external surfaces
• Integrated exhaust routing for equipment with combustion exhaust (gas engines, diesel generators)
• Integrated climate control using Ex-Machinery explosion proof air conditioning units
• BMS or Industrial DCS integration via dry contacts or industrial protocol
• Redundant pressurisation with dual-fan configuration for critical applications

Ex-p Versus Ex-d, Ex-e and Ex-i

An Ex-p (pressurised) approach differs from Ex-d (flameproof), Ex-e (increased safety) and Ex-i (intrinsically safe) in one important way: it protects an entire room or container rather than each individual item of equipment. For projects where many components need to sit together in the same hazardous area, or where the equipment simply is not available in ATEX-certified form, a pressurised container is usually the most economical and the most flexible route to compliance.

Protection Types Pz, Pv, Px and Py

The standard type of protection for the Ex-M Pressurised Container is pz, which allows ATEX Zone 2 (Gc) equipment protection level requirements to be reduced to non-hazardous by maintaining overpressure and dilution. Alternative protection types are available on request: pv for non-hazardous areas with an internal release, px for reducing Zone 1 (Gb) to non-hazardous, and py for reducing Zone 1 (Gb) to Zone 2 (Gc).

When the pressurised room houses an internal source of flammable substance, for example fuel-gas piping feeding a gas engine, the design follows Clause 10 of EN 60079-13. Releases are diluted by ventilation to below 25% LEL, and a shut-off valve located outside the container limits the maximum possible release. Factory testing per Annex III covers mechanical strength, overpressure, purging, minimum pressure differential and minimum flow rate.

Standard Safety Instrumentation

• Sensors: pressure differential, air flow, and gas detection when an internal flammable source is present
• Switches: door switches with open-time monitoring
• Alarms: alarm lights and sirens, inside and outside the pressurised container
• Valves: over-pressure relief and automatic shut-off on the flammable substance supply
• Control: automatic purge cycle before start-up, automatic shutdown on loss of protection
• Signage: mandatory EN 60079-13 markings (Authorized Personnel Only; Pressurised room, keep door closed; Danger, do not enter during alarm)

Typical Spare Parts on Request

• Pressure-differential sensor
• Air-flow sensor
• Gas detector head
• Alarm light and siren
• Door switches
• Ventilation fan

The explosion proof pressurised container is the pragmatic answer for any hazardous-area project where the equipment you need is not available in ATEX-certified form, or where certifying every individual component is not economically viable. Typical applications for an ATEX pressurised room or Ex-p enclosure include:

• Gas engine ATEX enclosures
• Diesel generator pressurised containers
• Offshore MCC and switchgear rooms
• Analyser houses and sampling shelters
• Operator shelters in hazardous areas
• Control rooms inside Zone 2 areas
• Battery rooms and UPS rooms
• Gas compressor station enclosures
• Onshore and offshore production platforms
• FPSOs and drilling rigs
• Refineries
• Petrochemical plants
• Chemical plants
• Fuel storage and loading terminals
• Pharmaceutical facilities
• Paint and coating shops
• Hydrogen electrolyser containers

With over 20 years of expertise in explosion safety, Ex-Machinery combines advanced engineering with strict adherence to IEC EN 60079-13 to deliver pressurised containers and Ex-p rooms tailored to your project. Key advantages:

• Expert Advice: over 20 years of ATEX and explosion-safety engineering
• Service-Oriented: responses within one business day
• Technical Construction File: delivered with every pressurised container
• Custom Projects: pressurised rooms engineered around your specific equipment and site
• Extended Warranty: five-year parts warranty
• After-Sales Support: spare parts, inspections and commissioning support

For more information or to request a quotation for your Ex-p container project, contact our sales engineers.