With the improvement of intelligence and automation level in coal mines, higher requirements have been put forward for underground fluid control equipment. Traditional manual or split type valves have problems such as slow response, difficult maintenance, and significant safety hazards. The mining flameproof integrated electric gate valve highly integrates the electric actuator with the gate valve body, and adopts a flameproof shell enclosure to ensure operational convenience while meeting explosion-proof safety regulations in the special environment of coal mines. It has become a core component of modern mine fluid control systems.

1. Integrated Integrated Architecture

The mining explosion-proof integrated electric gate valve adopts a "valve body actuator integration" design, eliminating traditional couplings and external brackets, significantly reducing volume, lowering installation space requirements, and reducing the risk of failure caused by loose connections. The main components include:

-Valve body (usually wedge or parallel gate structure)

-Explosion proof electric actuator (including motor, reducer, stroke/torque control module)

-Explosion proof shell (made of cast steel or ductile iron, in accordance with the requirements of GB/T 3836.2)

-Manual switching device (emergency operation function)

-Cable entry device (with explosion-proof gland)

2. Key materials and sealing design

The valve body and valve cover are mostly made of WCB carbon steel or stainless steel, suitable for media such as mine water and mud; Hard alloy welding or elastic sealing structures are often used for sealing pairs to ensure long-term shutdown and zero leakage. All exposed metal components undergo anti-corrosion treatment to meet the corrosion resistance requirements of MT/T industry standards.

2、 Explosion proof principle and implementation of explosion-proof structure

1. Basic principles of explosion-proof

According to GB 3836.1/2 (equivalent to IEC 60079-0/1) standard, explosion-proof (Ex d) equipment seals electrical components that may generate sparks, arcs, or high temperatures inside through a sturdy enclosure. Even if an internal explosion occurs, the shell can withstand the explosion pressure and cool the flame through specific gaps (explosion-proof joint surfaces) to prevent ignition of external combustible gases.

2. Explosion proof joint surface design

-The joint surface of the shell flange adopts a joint and flat composite structure, with a joint surface width of ≥ 25 mm and a gap of ≤ 0.20 mm (according to the requirements of Class I equipment)

-Explosion proof parameters that meet the standards are set for dynamic/static parts such as bearing holes and cable entry ports

-All fastening bolts have anti loosening measures to ensure the integrity of the joint surface during long-term use

3. Explosion proof certification and marking

The product must be certified by a nationally authorized explosion-proof inspection agency and obtain an Ex d I Mb explosion-proof certificate, including:

- “Ex d” 表示隔爆型

-'I' represents electrical equipment used in coal mines

-Mb "indicates that the equipment is allowed to have explosive gas environments when powered on (applicable to mining workfaces)

3、 Explosion proof performance testing and verification

Typical testing projects include:

-Shell pressure resistance and internal ignition non explosion test (1.5 times working pressure holding, simulating internal CH ₄/H ₂ mixture explosion);

-Temperature rise test (surface temperature of motor during full load operation ≤ 150 ° C, below the minimum ignition temperature of methane);

-Protection level test (usually IP68, suitable for underground humid and dusty environments);

Actual testing has shown that qualified mining explosion-proof integrated electric gate valves have not experienced shell rupture or flame leakage under simulated explosion conditions, meeting the requirements for safe use.

4、 Application advantages and engineering value

-High safety: effectively isolate electrical sparks and eliminate the risk of detonation;

-Convenient maintenance: The integrated structure reduces the number of fault points and supports on-site/remote diagnosis;

-Automation compatibility: Can be connected to the mine centralized control system to achieve remote switching and status feedback;

-Strong reliability: adaptable to harsh working conditions such as frequent start stop, high dust, and high humidity;

The mining explosion-proof integrated electric gate valve achieves the unity of high safety and high reliability through scientific structural integration and strict explosion-proof design. It not only meets national and industry standards such as GB 3836 and MT/T 715, but also meets the practical needs of the intelligent development of coal mines. In the future, with the advancement of material technology and intelligent control technology, this type of product will continue to upgrade in sealing life, energy efficiency optimization, and digital twin operation and maintenance, providing stronger guarantees for mining safety production.