What are the differences between a pressurized explosion-proof enclosure and a structural explosion-proof enclosure?

The analysis shelter is an emerging technology that has gained international popularity. It integrates the combination, assembly, and installation of industrial online instruments and has been widely adopted in refineries and chemical plants. The standardized and modular design of on-site analysis rooms facilitates the installation and maintenance of instruments while providing an optimal operating environment, leading to their increasing application in process units. Explosion-proof analysis shelters are suitable for Class II, Division 2 hazardous gas environments, accommodating gases or vapors of Class IIA, IIB, and IIC with temperature groups T1 to T4. They are designed for use at altitudes not exceeding 2,000 meters, relative humidity below 95% at 25°C, and operating ambient temperatures between -20°C and +40°C.  Structurally, all equipment inside the explosion-proof analysis shelter is treated for explosion protection. All electrified devices installed in the shelter, such as power distribution equipment, lighting, ventilation systems, and analyzers, are independent explosion-proof components certified as standalone explosion-proof products. Hazardous gases entering the shelter are expelled via explosion-proof exhaust fans. Even if external hazardous gases infiltrate the interior, all internal equipment remains explosion-proof, ensuring overall excellent explosion protection.
Pressurized explosion-proof shelters, also known as explosion-proof pressurized shelters, prevent external gases from entering by maintaining a slight positive pressure inside. This achieves explosion protection. Since the shelter itself is explosion-proof, the internal instruments and equipment do not need to be explosion-proof. Pressurized ventilation-type explosion-proof analysis shelters can house non-explosion-proof analyzers and various instrument cabinets. Only after the explosion-proof pressurized system is operational and positive pressure is established inside can the non-explosion-proof components be powered on.  This technical requirement primarily applies to pressurized explosion-proof analysis shelters. The specifications for analysis shelters are designed and manufactured in accordance with national standards GB3836.1-2010 "Explosive Atmospheres - Part 1: Equipment - General Requirements," GB3836.2-2010 "Explosive Atmospheres - Part 2: Equipment Protected by Flameproof Enclosure 'd'," GB3836.5-2004 "Electrical Apparatus for Explosive Gas Atmospheres - Part 5: Pressurized Enclosure 'p'," GB3836.13-2013 "Explosive Atmospheres - Part 13: Equipment Repair, Overhaul, and Reclamation," GB3836.15-2000 "Electrical Apparatus for Explosive Gas Atmospheres - Part 15: Electrical Installations in Hazardous Areas (Other than Mines)," and GB3836.17-2007 "Electrical Apparatus for Explosive Gas Atmospheres - Part 17: Construction and Use of Pressurized Rooms or Buildings."
Widely used in refining, chemical, metallurgical, pharmaceutical, and light industries, these shelters provide a safe installation space and protection for various online process gas analyzers and online water quality analyzers. The analysis shelter measures 3000×3000×2700 (L×W×H) mm. It includes 2 sets of SIEMENS chromatographs, 1 combustible gas detector, 2 sets of sample gas sampling probes, 2 sets of pre-treatment for sample gas, and 2 sets of post-treatment for sample gas (installed at the back of the shelter). Additionally, it houses 4 bottles of 40L carrier gas and 2 bottles of 8L standard gas. The pressure inside the pressurized shelter is generally maintained at 25-50 Pa. The internal configuration of explosion-proof shelters is customized according to client requirements, with each client having unique needs. As manufacturers, we also provide technical guidance based on the specific on-site requirements of clients.
The online water quality analyzer explosion-proof shelter is a water quality monitoring tool capable of automatically monitoring various water quality parameters in real time. It meets the needs of industries such as water supply, medicine, pharmaceuticals, wastewater treatment, municipal services, power and energy, food processing, plastics, automotive, semiconductor, tire manufacturing, metallurgy, material processing, mining, printing, and oil and gas.