Spirax Sarco BBV series boiler bottom blowdown valves, including models BBV43, BBV63, and BBV83, are available in manual and compressed air/water actuated versions, with sizes from DN15 to DN65. Valve bodies are available in carbon steel, stainless steel, or alloy steel. Maximum operating temperature is 580°C, and maximum allowable pressure is 100 bar g. Designed for intermittent bottom blowdown of steam boilers, the valves use flow pressure to assist closing and effectively remove suspended matter and settled solids. A timer controller enables automatic blowdown and reduces heat loss. A mechanical switch box is also available to monitor an open valve condition.
Spirax Sarco BBV boiler bottom blowdown valve front view
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BBV Boiler Bottom Blowdown Valve | Spirax Sarco
Intermittent bottom blowdown valves for steam boilers, with sizes from DN15 to DN65 and manual or compressed air/water actuated automatic timed control.
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Specifications
- Valve Type
- Boiler Bottom Blowdown Valve
- Actuation Method
- Compressed air/water actuated type (with manual handle), manual type
- Nominal Diameter
- DN15, DN20, DN25, DN32, DN40, DN50, DN65
- Flange Standards and Pressure Ratings
- EN 1092 PN40/PN63/PN100, ASME 150/300/600, JIS/KS 30/40
- Body Material
- carbon steel (BBV4), stainless steel (BBV6), alloy steel (BBV8)
- Plug Material
- stainless steel
- Seat Material
- stainless steel, cobalt-chromium-tungsten hardfacing
- Packing (Standard)
- PTFE
- Packing (High Temperature)
- Graphite
- Diaphragm Material
- Reinforced NBR
- Kv Value
- 1.6~16
- Seat Diameter
- 8~25 mm
- Minimum Operating Temperature
- -29°C
- Maximum Operating Temperature (Standard PTFE Seal)
- 250°C
- Maximum Operating Temperature (High-Temperature Graphite Packing)
- 400~580°C (depending on body material)
- Maximum Allowable Pressure (PN100)
- 100 bar g (BBV43 at 50°C, BBV63 at 100°C, BBV83 at 250°C)
- Maximum Allowable Pressure (PN40)
- 40 bar g (BBV43 at 50°C, BBV63 at 100°C)
- Maximum Design Cold Hydraulic Test Pressure
- 156 bar g (PN100/PN63), 60 bar g (PN40)
- Safety Certification
- PED 97/23/EC
- Material Certification
- EN 10204 3.1
Application scenarios
Intermittent bottom blowdown of steam boilers
Installed in the bottom blowdown piping of steam boilers, it removes suspended matter, deposited solids, and liquid accumulated at the bottom of the boiler. The BBV valve is specifically designed for boiler bottom blowdown, and flow pressure assists valve closure.
Automatic boiler bottom blowdown with a timer controller
Pneumatic or water-operated BBV valves, as well as automatic BBV valves upgraded from manual versions, can be used with Spirax Sarco blowdown controllers for timed control of boiler bottom blowdown. This helps prevent repeated or missed blowdown operations and reduces blowdown heat loss.
Monitoring of boiler room blowdown valves that remain open
The BBV blowdown valve can be fitted with an optional mechanical switch box and connected to a blowdown controller or BMS. It sends an indication signal when the valve is not closed, enabling monitoring of blowdown valve status in the boiler room.
FAQ
What is the function of the BBV boiler bottom blowdown valve, and why is it suitable for bottom blowdown?
BBV is specifically designed for steam boiler bottom blowdown to discharge suspended or deposited solids and liquids from the bottom of the boiler. The valve uses a dedicated spindle sealing structure with self-adjusting and self-cleaning characteristics. In addition, flow pressure assists valve closure, making it suitable for applications requiring rapid and reliable bottom blowdown.
How should the BBV manual type and compressed air/water actuated type be selected?
BBV M is a manual type with a manual handle, suitable for applications where blowdown is performed manually. BBV PN/M is actuated by compressed air or water and fitted with a manual handle for both automatic and manual operation. The PN/M type closes automatically under spring force in the event of a power failure. All M manual types can be upgraded to PN/M automatic types; the specific configuration should be confirmed based on the actual control method and application conditions.
Can the BBV automatic type be connected to a boiler blowdown controller or BMS system?
Yes. When used with a Spirax Sarco automatic bottom blowdown timer controller, the automatic BBV enables timed blowdown, reducing repeated or missed blowdown and helping minimize blowdown heat losses. The valve can also be fitted with a mechanical switch box for connection to a blowdown controller or BMS system. The switch box provides an indication signal when the valve is not closed.
How should body material and sealing be matched when selecting BBV43, BBV63, or BBV83?
BBV43 uses a carbon steel body, BBV63 uses a stainless steel body, and BBV83 uses an alloy steel body. Spindle sealing can be selected as PTFE sealing or high-temperature graphite packing. The maximum operating temperature for standard PTFE sealing is 250°C, while high-temperature packing H is suitable for higher temperature ranges. Selection should consider the body material, connection rating, actual operating pressure, temperature, and pressure/temperature limitation curves.
What sizes and pipeline connection methods are available for the BBV, and which spare parts can be replaced during maintenance?
BBV is available in DN15 to DN65 sizes, corresponding to 1/2 inch to 2 1/2 inch specifications. Standard flanged connections include EN 1092 PN40, PN63, PN100, ASME 300, and ASME 600. Butt weld, socket weld, JIS/KS 30, and JIS/KS 40 connection options are also available. Available spare parts include actuator retaining nuts, seal ring assemblies, spindle seal assemblies, and quick-opening plug and seat assemblies. When ordering spare parts, specify the complete product description, valve model, and size shown on the body label.