Caloritech is the process-heating brand of Thermon, a US company best known for heat tracing. Thermon’s Ruffneck line covers explosion-proof electric unit heaters and convection heaters built for oil and gas sites, and the Caloritech name also appears on electric boilers.

Best fit: North American process-heating projects that also need heat tracing from the same supplier.

Check first: some Caloritech models, such as the BX convection heater, are not intended for hazardous locations. Confirm the certification of the exact model you plan to buy.

Chromalox is one of the oldest names in electric heating. Its first product was a strip heater, and it has been part of Spirax-Sarco, now Spirax Group, since 2017. It sells industrial heaters, heat tracing and packaged heating systems. UK distributor listings describe Ex d flameproof and Ex e increased-safety heaters for Zone 1 and Zone 2.

Best fit: large projects that want packaged systems and controls from one global brand.

Check first: lead time and local service cover for custom units, which can vary by region.

EXHEAT builds hazardous-area electric heating and control equipment in the UK. Its catalogue runs from small enclosure heaters and air warmers to tank immersion heaters and a portable fan heater, with ATEX, UKEx and IECEx certification listed through its UK distributor.

Best fit: smaller hazardous-area jobs, such as cabinets, workshops and compact tank heating, where UK or European certification is required.

Check first: the sources we used did not confirm EXHEAT’s founding year or ownership, so verify both directly with the company.

Runkel Electric Heating was set up in 2015 as the foreign-trade arm of the Yangzhong Sanhuan group and works with group plants in Yangzhong, Shijiazhuang and Shenyang. Its 2026 brochure lists explosion-proof, circulation, bundle and duct heaters, food-grade explosion-proof heaters, tubular and liquid heating elements, PTC heaters, cartridge heaters, flexible ceramic heaters, bolt heaters and tube-production machines.

Circulation heater units are listed at 380 V up to 3,000 kW, and high-temperature duct heaters from 10 to 3,000 kW at 220 to 380 V.

Best fit: buyers who want a China-based maker to engineer custom explosion-proof, circulation or duct heaters to a specification, with price as a deciding factor.

Check first: the certificates shown in Runkel’s brochure are issued to group manufacturing companies, so request the one that names your model, zone and temperature class.

Vulcanic has made electric heating and cooling equipment since 1973. Its range includes immersion heaters, flow heaters, air duct heaters, heating cables and controls, with ATEX versions of the immersion and flow heaters. Spirax Group agreed to buy it in 2022, so it now sits alongside Chromalox.

Best fit: European sites that need ATEX-marked immersion or flow heaters.

Check first: the notified body and certificate number printed in the ATEX marking of your model.

Watlow designs industrial heaters, sensors, controllers and system assemblies. That mix of heating and control hardware suits projects that need the whole thermal loop from one supplier.

Best fit: equipment makers and process lines that need heaters matched with sensors and controllers.

Check first: the sources we used did not detail Watlow’s hazardous-area range, so ask for model-level certificates.