The high pressure feedwater heater is a mainstay in the steam-electric power station. It extracts the exhausted steam from a steam turbine and uses it to heat the water being delivered to a steam boiler.

If the feedwater heater breaks down, water would only have to bypass the heater and enter into the boiler from a side pipeline. Water that is fed into the boiler without being preheated requires more fuel to reach boiling point. Heating water too fast or violently causes severe damage to the boiler metal because of thermal shock. It also decreases thermal efficiency of the whole steam cycle.

Jinan Pressure Vessel Factory is specialist manufacturer of high pressure feed water heater which is in essential a shell and tube heat exchanger. Arranged in the upper part of the internal shell is a condenser while a cooling section is fitted to the bottom of inside the shell for effective cooling of hot condensate. There are also feed water inlets and outlets. The tubes are connected to the tubesheets via welding and hydro-expanding. Available also at the tube-side inlet port are wear-resistant nozzle shroud and distributor plate to distribute fluids evenly in the tubes.

The energy used to heat the feedwater is provided by exhaust from the steam turbine other than an external heat source. Therefore, the high pressure feedwater heater consumes little energy. Its compact design takes up very small space, and its construction requires minimized use of materials. With this heating equipment, users also can easily control the water level, flow rate and heater terminal temperature difference.

Models
Vertical U-tube unit, inverted vertical U-tube type, horizontal version

Structure
Tubes: Imported or domestic U-shaped seamless tube made of high-quality carbon steel, stainless steel tube, alloy steel tube
Water box(another name for bonnet, channel, shell head, or header): gasketed shell head with large openings, or gasketed hemispherical shell head with small openings
Shell: 1-section shell (condensation section), 2-section shell (overheated steam cooling section, condensation section), 3-section shell(overheated steam cooling section, condensation section, hot condensate cooling section)

Features
1. The high pressure feedwater heater consists of a shell with a bundle of tubes inside it. The space outside the tubes but inside the shell is called the shell side while the space confined within the tubes is known as the tube side.
2. Separated by baffles inside the shell are 3 sections where overheated steam condensation, saturated steam cooling, and hot condensate cooling take place. The flow passage on the shell side takes the shape of an S to enhance turbulence and heat exchange rate.
3. The tube side space consists of a water box, U-tube bundle, and outlet pipe. At one end of the water box is a man-hole for easy maintenance and inspection of the tubes.
4. An automatic condensate flow regulator is in place to control the way water flows during a normal operation as well as in situations where a heater failure is experienced. Under normal operating conditions, the heater allows water to cascade down into the boiler by gravity. When the feedwater heater break-down does occur, water would flow directly to a flash tank.
5. There are relief valves on both the tube side and shell side for maximum operating safety.
6. 3 magnetic level switches are utilized to control water level by sounding the alarm. They are linked to the motor-driven steam extraction valve.