What Refinery Operations Actually Need From an Explosion-Proof Radio: Five Scenarios That Determine the Right Choice

Comparing radio brands for a refinery is the wrong starting point. The right starting point is what the refinery's specific operating scenarios require from the radio system, and then asking whether a proposed solution meets those requirements. A refinery is not a uniform environment: the communication demands at a crude distillation unit differ from those at a loading rack, and both differ from what a lone instrument technician in a confined space needs. The radio that is correct for one scenario may be inadequate for another, and a procurement decision that does not work through each scenario will produce a mixed result in the field.

In Brief

Refinery operations span five distinct communication scenarios, each placing different requirements on the radio system. For Zone 1 process areas where hydrogen or IIC gas group substances are present, the HP71XEx IIC and HP79XEx IIC provide dual IECEx and ATEX IIC certification alongside 2W AI noise cancellation audio for compressor and pump-noise environments. For loading rack coordination and spill alerting, the same terminals connect to a DMR trunking or TETRA network that delivers group call priority and emergency pre-emption.

For confined space and maintenance entry, the PT890Ex and E-pack200 portable repeater extend TETRA Direct Mode coverage into areas where the main network signal does not reach. For lone worker and instrument rounds, Man Down alarm with location reporting is confirmed on both HP71XEx IIC and HP79XEx IIC. For control room dispatch, the DS-6250S outdoor trunking base station and Hytera ICC platform provide the infrastructure and dispatch layer that ties all field teams into a single coordinated view.

Scenario One: Zone 1 Process Areas on an Active Refinery

The crude distillation unit, catalytic cracker, hydrotreater, and hydrogen plant are the high-hazard core of a refinery. Hydrogen is present as a feedstock and process gas across multiple units. Acetylene appears in specific streams. Both are IIC gas group substances, meaning they have the lowest minimum ignition energy of any standard industrial gas classification.

Every terminal operating in these areas must carry IIC certification. IIA or IIB certification is not compliant where hydrogen is present, regardless of the terminal's other features. This is not a preference; it is a binary requirement determined by the site's hazardous area classification and the gas group of the substances present.

The HP71XEx IIC and HP79XEx IIC carry dual IECEx and ATEX IIC certification for Zone 1 and Zone 2 gas atmospheres and dust Zone 21 and Zone 22. The operating temperature range in classified areas is -25°C to +60°C, covering outdoor winter conditions and the elevated ambient temperatures near fired heaters and heat exchangers.

The 2W high-power speaker with AI noise reduction and AGC addresses the compressor and pump-station noise that makes lower-output speakers inaudible at close range.

The HP79XEx has a 2.4-inch display suited to shift supervisors and area coordinators who need to navigate group lists and read messages in the field. The HP71XEx has a 1.47-inch display suited to operators, technicians, and maintenance workers where compact carry and one-handed operation are the priority.

Both models are in the same product generation with identical certification, audio platform, and connectivity.

Scenario Two: Loading Rack Coordination and Spill Response

The loading rack is where a refinery's operational pressure and its highest ignition risk overlap. Tank trucks and rail cars are loaded under tight scheduling windows; hoses connect to lines carrying light ends and other flammable products; and a miscommunication during valve switching or product transfer can escalate into a spill or fire within seconds.

Communication at a loading rack requires three capabilities simultaneously: coordinated group calls for routine bay scheduling, individual calls for permit confirmation, and emergency call pre-emption that reaches every relevant person instantly when a spill is detected.

On a DMR Tier III trunking system, the trunking controller manages all three call types on a shared channel pool, with priority and pre-emption configured so emergency calls always find a channel regardless of routine traffic load. On a TETRA system, emergency call pre-emption is defined at the protocol level rather than requiring per-site configuration, providing consistent behaviour across all registered terminals.

For loading rack deployments where the terminal must also interface with remote PA broadcasting for public area alerts, the Hytera DTT806 network unit connects the PMR network to the site's PA system, allowing a dispatch operator to trigger zone-specific broadcasts over the radio network without switching to a separate PA control interface.

Scenario Three: Confined Space and Maintenance Entry

Vessel entries, exchanger bundle pulls, column internals inspections, and underground sewer system work all require a worker to enter an enclosed space where the main radio network signal does not reliably reach. A Zone 1 terminal that loses contact with the control room the moment the worker descends below the vessel manway has not solved the communication problem for this scenario.

TETRA Direct Mode Operation (DMO) provides peer-to-peer communication between terminals without any base station involvement. A worker entering a vessel can maintain voice contact with the standby person at the entry point as long as both carry TETRA terminals and the distance between them is within direct radio-to-radio range. The PT890Ex supports DMO alongside TETRA trunking mode, with IIC certification and battery life of up to 26 hours in TMO and 20 hours in DMO under a 5-5-90 duty cycle.

For deeper penetration into large vessels, underground pump rooms, or multi-floor process buildings, the E-pack200 portable DMR ad-hoc repeater creates a relay chain without fixed installation. A standby worker positions the E-pack200 at the vessel entry point; the device receives the confined-space worker's transmission and retransmits it to the main radio network outside. Coverage extends floor by floor or passage by passage as team members carry additional units.

Scenario Four: Lone Worker and Instrument Rounds

Instrument technicians, patrol operators, and safety walkers on a large refinery frequently work in remote process areas without direct line of sight to other personnel. If a worker is incapacitated by a fall, heat stress, or gas exposure, the communication system is the primary means by which that event is detected.

Man Down alarm activates automatically when the terminal detects a fall or extended period of inactivity beyond a configured threshold. It transmits an alert to the dispatch console with the activating terminal's ID and, where GNSS is configured, the device's location. This removes the dependency on the incapacitated worker being able to press the emergency button manually.

Man Down alarm with location reporting is confirmed on both the HP71XEx IIC and HP79XEx IIC. GNSS positioning is a configurable feature on both models. For operations where lone worker rules require timed check-ins, confirm the Lone Worker feature configuration for the specific firmware version and DMR system setup with Hytera. The relevant dispatcher platform should display Man Down activations distinctly from routine emergency button presses to allow appropriate response prioritisation.

Scenario Five: Control Room Dispatch and Fleet Visibility

A refinery control room managing multiple units simultaneously needs more than a radio channel. It needs to know where every field team is, which group calls are active, and which terminals have triggered emergency or Man Down alerts, all in real time and from a single interface.

The Hytera Integrated Command and Control (ICC) platform consolidates DMR, TETRA, LTE, and analogue network terminals into a single GIS-based dispatch view. GPS location data from all active terminals, group call status, and emergency alerts are visible from one console without switching between separate applications for each radio standard.

For refineries with both a private DMR network and areas covered by public LTE, the PDC680 dual-mode terminal registers on both networks under the same ID, maintaining dispatch visibility as workers move between coverage zones.

For the outdoor infrastructure layer, the DS-6250S outdoor trunking base station deploys on walls, poles, or trolleys across the site without dedicated equipment rooms. Its IP68 rating, -40°C to +55°C operating range, and 20 kA lightning protection address the outdoor process area environment where a traditional base station shelter is impractical.

Frequently Asked Questions About Explosion-Proof Radios for Refinery Operations

Do all areas of a refinery require IIC-certified terminals?

No. The required certification for each area follows from the hazardous area classification survey, which maps every area of the site to its zone classification and gas group. Administrative buildings, control rooms with positive pressure ventilation, and areas classified as non-hazardous do not require IS-certified terminals at all. Areas classified Zone 2 with IIA gas group atmospheres may be served by IIA-certified terminals.

Only areas where IIC gas group substances such as hydrogen are present require IIC certification. Confirm the classification for each deployment area with the site's HSE function before specifying terminals.

Can the same terminal model cover both Zone 1 and Zone 2 areas?

Yes. IEC and ATEX Zone 1 equipment (Category 2) is fully compliant in Zone 2 areas, as Zone 2 is a less hazardous classification. Deploying IIC-certified Zone 1 terminals across both Zone 1 and Zone 2 areas of the refinery provides a single terminal type for the entire classified site, simplifying procurement, training, spares management, and accessory certification. The HP71XEx IIC and HP79XEx IIC are Zone 1-rated (Category 2G) and IIC gas group certified.

What happens to Man Down alerts when a worker is in a confined space without network coverage?

On a TETRA system with DMO enabled, a Man Down activation from a terminal operating in DMO mode will alert other terminals within direct radio-to-radio range, including the standby person at the vessel entry point. The alert may not reach the main dispatch console until the relay chain connects back to the network. For DMR terminals in a confined space without trunking coverage, Man Down activation triggers a local alert behaviour on the terminal and on any nearby terminals on the same channel, but dispatch console notification depends on network connectivity. Confirm the specific Man Down alert routing for confined space scenarios with the Hytera team during system design.

Evaluate Scenarios Before Comparing Specifications

A refinery is not a single radio deployment problem. It is five overlapping communication scenarios, each with specific requirements that must all be met simultaneously by the system as a whole. The evaluation question is not which brand performs better on a feature list; it is which solution addresses all five scenarios with certified equipment, validated coverage design, and a dispatch layer that gives the control room the visibility it needs.

Hytera's IS portfolio, dispatch platform, and infrastructure range are designed to address each of these scenarios. Visit the Hytera Oil and Gas Solutions page or contact a Hytera specialist for a refinery-specific system assessment.