What Are Boiler Blowdown Valves?
Boiler blowdown valves are used to remove dissolved solids, sludge, and scale from steam boilers. As water is converted to steam, the dissolved minerals and solids remain behind and concentrate in the boiler water. Without regular blowdown, TDS (Total Dissolved Solids) levels rise — causing scale formation, corrosion, and carry-over of impurities into the steam.
GESTRA blowdown valves provide safe, reliable, and controllable blowdown for steam boilers of all sizes. PureSys India supplies GESTRA’s blowdown valve range — visit our GESTRA brand page or boiler equipment section.
Types of Boiler Blowdown
Bottom Blowdown (Intermittent Blowdown)
Bottom blowdown removes settled sludge and heavy solids from the bottom of the boiler drum. It is done intermittently — typically once or twice per shift — using a quick-acting blow-off valve. GESTRA bottom blowdown valves feature:
- Quick-opening design for effective sludge removal
- Robust construction for high-pressure, high-temperature service
- Available with slow-opening safety valve in series for enhanced protection
- Suitable for boiler pressures up to 40 bar and beyond
Surface Blowdown (Continuous Blowdown)
Surface blowdown removes dissolved solids from the water surface continuously — maintaining TDS within prescribed limits automatically. GESTRA continuous blowdown systems include:
- TDS controllers and conductivity sensors
- Motorised blowdown control valves
- Blowdown heat recovery systems — reclaiming energy from hot blowdown water
Why Correct Blowdown Is Essential
- Scale prevention: Scale on heat transfer surfaces reduces efficiency and causes overheating
- Steam quality: High TDS causes wet steam and carry-over, damaging downstream equipment
- Corrosion prevention: Excess chlorides and dissolved oxygen cause boiler corrosion
- Regulatory compliance: Indian boiler regulations require maintained water quality
GESTRA Blowdown Valve Features
- Forged steel body — exceptional durability in high-pressure service
- Hardened stainless steel trim — resists erosion from flashing blowdown
- Available in slow-opening and quick-opening designs
- Pressure ratings: PN 40 to PN 160
- Temperature ratings: up to 350°C
Blowdown Heat Recovery
Hot boiler blowdown at 10 bar contains significant energy. GESTRA blowdown heat recovery systems flash the blowdown water to low-pressure steam, recovering energy for boiler feedwater heating — reducing fuel consumption by up to 2%.
Get Expert Advice
PureSys India’s boiler engineers will specify the right GESTRA blowdown valve for your boiler. Contact us today or explore our steam audit service to assess your boiler efficiency.