Boiler Feed Water Valve Fail Position

There are a few different fail scenarios.

Boiler feed water valve fail position. Safety valve lifting and then reseating. N failure mode fail safe is the preferred failure mode which. Feedwater control valves play a critical role in boiler operation. One important parameter of their design is the pressure drop at the rated condition as well as off design conditions.

Each having its own consequences and safety effects. To protect against this the feedwater valves are sized for minimal pressure. Off of many types of signals. It is critical not to allow the hrsg to dry out which can cause severe thermal damage to the boiler tubes and the drums.

Loss of plant air pressure to the control valve actuator. The backflow preventer offers added protection preventing the system from emptying if supply pressure should fail. The valve s fail position is a safety precaution that protects your process in emergency situations. Loss of water to the deaerator or makeup water system.

They come in all types from ball valves to knife gates to globe valves and operate. Modulating feedwater valves allow for constant incremental adjustments to feed water into your boiler. Coupling dependable service with added protection into one quality product is taco s combination boiler feed backflow preventer valve. Prevention of scaling or buildup the need for proper feedwater treatment is obvious if you will consider the comparison of a boiler and a pot of boiling water on the stove.

Drum level controller failure. Be a boiler feedwater regulator valve where a constant speed feed pump is used. Large and sudden change in steam load and or. Drum level controller inadvertently left in manual position.

Some typical applications are 0 135 ohm slide wires from a mcdonnell and miller 7b switch or a 4 20ma signal from a. Pressure drop so flow control is established by the valve position. The feedwater valves are normally sized to accommodate an operating condition that occurs when the safety valves open during a unit trip. Boiler feedwater is treated to protect it from two basic problems.

The buildup of solid deposits on the interior or water side of the tubes and corrosion.