Hydraulic valves for hazardous areas
Hydraulic systems must work safely and reliably in potentially explosive areas. ARGO-HYTOS has been offering safe EX valves for more than ten years for mines, chemical or petrochemical plants as well as dust areas prone to explosion.
The valves are designed according to explosion protection class EPL b. This corresponds to a “high” level of protection for the use in particularly hazardous areas where there is a chance of ignition during normal operation or foreseeable faults and malfunctions.
Coil operated explosion proof valves are available on the market in different versions. Each of them consists of an electrical part, the solenoid control coil and a mechanical part, which includes the control system and the hydraulic section.
The basic protection for the solenoid coil is an encapsulation with insulating material (protection class m, EN 60079-18). The terminal strip for the electrical connection of the coil as well as the cable gland are certified according to e (EN 60079-7). Our EX valves are certified for hazardous dust areas prone to explosion according to protection class t (EN 60079-31).
The coils themselves are certified according to the European Directive 2014/34/EU and the internationally applicable IECEx as well as other national standards.
The power rating is related to the maximum surface temperature of the coil, which in turn is divided into classes: valves with a 10 W coil can be used in temperature classes T4 (135 °C), T5 (100 °C) or T6 (85 °C), provided that the power supply, ambient and fluid temperature specifications are not exceeded. The 18 watt variant can only be used in the T4 class due to its higher power dissipation.
The valves can be equipped with a manual emergency control, in case of coil or power failure. The manual override can be controlled up to 25 bar pressure in the control system. A spool operated directional control valve with built-in manual control allows operation at up to 100 bar pressure at the T-port. This does not affect the normal coil control.
- Explosion-proof operation
- Certified according to international standards
- Flexible power supply
- Corrosion resistant
- Insensitive to mechanical stress
- Can be utilized under difficult conditions in mines