CONTROL VALVE APPLICATIONS
BOILER FEED • Using Water Control Valve with Cavitation Control
PURPOSE:
For accurate supply of feed water into a boiler.
OPERATION:
The boiler feed control valve is connected to a controller and level transmitter which monitors the water level in the boiler. When water level drops, the controller sends a signal to the control valve to modulate open to supply additional feed water as needed. This arrangement limits cycling of the feed water pump and provides more consistent steam load and supply pressure from the boiler.
INSTALLATION GUIDELINES:
(see Figure 19)
• Depending on the required pressure and temperature of feed water, cavitation may be present due to pressure drop and recovery through the control valve. Cavitation can cause noise, vibration, and damage to control valves and piping. If cavitation will exist in a particular application, cavitation adapters should be used to mitigate its effects. For control valve and cavitation adapter sizing, consult the factory or Steam Worx sizing program on www.watsonmcdaniel.com. • For optimum operation and service life, maintain recommended minimum piping straight runs before and after the control valve. Inlet and outlet piping should be sized to maintain appropriate velocities for the feed water. • When the valve actuator is electric, plan the installation location of the valve so that ambient conditions do not exceed the limits of the actuator. Insulation blankets may also be used for protection. • Make certain there is at least one pipeline strainer installed between the feed water tank and the boiler feed control valve to protect the valve from pipeline scale and debris.
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www.watsonmcdaniel.com •• Pottstown PA • USA • Tel: 610-495-5131
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