In Montabert Hydraulic Rock Drill (or Hydraulic Drifter) systems, the Pressure Limiter 86664943 (control valve) acts as the “hydraulic pressure guardian”—it monitors and regulates the system’s working pressure in real time, ensuring it stays within the safe range (typically 1500-2000 psi for Montabert drills). Overpressure is one of the top causes of costly component failures: it can burst hydraulic hoses, damage the piston or cylinder, and even disable the entire drill—leading to $3,000+ in repairs and 2-3 days of unplanned downtime. With over a decade in mining equipment maintenance, I’ve seen generic control valves fail to address this risk: their low pressure precision (error ≥5%) leads to frequent pressure fluctuations, while weak valve cores wear out in 600-800 hours, losing pressure regulation ability.