Dorot S100 QR Series Cast Iron Hydraulic Quick Relief Valve with Relief Pilot

The Dorot S100 QR Series is a pilot-operated hydraulic quick relief valve designed to protect water systems from overpressure conditions by rapidly discharging excess pressure when preset thresholds are exceeded. Built from durable cast iron and equipped with a high-sensitivity relief pilot, this valve offers precise pressure regulation and fast response—making it ideal for pump stations, filtration systems, and irrigation networks where pressure surges can cause costly damage.

The relief pilot continuously monitors system pressure. When the pressure rises above the adjustable setpoint, the pilot triggers the diaphragm-actuated main valve to open instantly, releasing excess pressure through the outlet. Once pressure returns to safe levels, the valve closes smoothly, preventing water hammer and ensuring stable operation.

The S100 QR valve is compact, easy to maintain, and requires no external power, making it suitable for both manual and fully autonomous hydraulic control systems.

FEATURES

• Function: Pressure relief / surge protection
• Operation: Pilot-operated hydraulic quick relief
  
• Body Style: Globe-pattern (inline flow)
• Available Sizes: DN25 to DN100 (1" – 4")
  
• Max Fluid Temperature: 60°C (140°F)
• End Connections: Threaded, Flanged
• Body Material: Cast Iron 
• Bonnet: Cast Iron 
• Diaphragm: Reinforced Natural Rubber (optional: NBR, EPDM, Neoprene)
• Spring: Stainless Steel 302 
• Coating: Polyester Epoxy, Rubber, or Nylon
• Relay Valve Manual Override: Built-in 3-position selector

BENEFITS

• Provides rapid protection against dangerous overpressure conditions
• Opens instantly and closes smoothly to prevent secondary surges
• Adjustable relief pilot for precise pressure setpoint control
• Fully hydraulic—no external power or electronics required
• Rugged cast iron construction with corrosion-resistant coating
• Ideal for pumps, filtration systems, and critical irrigation junctions
• Easy maintenance with in-line serviceability