Questions regarding boiler blowdown valves

Compared to valves used in other applications, the blowdown valves of boilers have their own unique characteristics. 1. Boiler blowdown generally refers to the water inside the boiler, which is at high temperatures; especially in the boilers of thermal power plants, the temperature can be near the critical point of water, reaching over 270 degrees, while the pressure can reach over 20 MPa. Therefore, high-temperature and high-pressure valves are required for such applications. 2. Since it is a blowdown valve, there must be impurities in the water. These impurities typically include water containing various chemical agents, as well as deposits formed by hardness ions and phosphates. Some of these deposits adhere to the walls of the boiler, while others fall off as loose particles, also known as sludge. These water residues will be discharged through the drain valve, so this valve needs to be able to withstand solid particles in water, not get clogged by them and damaged, as well as have good sealing properties. 3. This operation is carried out frequently during waste discharge, so the valve also needs to have excellent operational durability.

So it’s necessary to write “waste discharge valve”, and not “angle valve”, right?

A corner valve is a type of valve structure, while a drain valve represents its function. When writing about it, don’t you also include the functions of the valve along with the technical specifications required? Your working hours must be long enough; there’s no need to teach you such things.

This doesn’t seem to have anything special about it, right?

Is that just an ordinary angle valve then?

The boiler drain valve is a type of valve specifically used in boiler systems, designed to discharge or vent wastewater, rainwater, condensate, and other liquids from the boiler system. Compared to ordinary angle valves, boiler drain valves typically possess higher heat resistance, corrosion resistance, and better sealing performance, in order to meet the special environmental requirements of boiler systems such as high temperatures, high pressures, and corrosive media. Therefore, to ensure the safe and stable operation of the boiler system, it is recommended to use blowdown valves specifically designed for boilers. .

It was explained very clearly. Thank you. Are there any manufacturer recommendations?

It depends on the pressure rating of the boiler. We are medium-pressure boilers operating at 3.85 Mpa and 450℃, equipped with domestic Shuanggao type waste discharge valves that offer decent durability. (The structure is not a ball valve, and the price is relatively low.) ) I have seen 30MW subcritical boilers, all of which use imported valves.