Technical Articles
The valve selection of waterworks (Part One)
Posted: 06/02/2018 10:22:39  Hits: 10
The conventional water production process of waterworks start from obtaining raw water, getting the raw water, getting sediment in the sedimentation tank, filtering the water in the filter tank to the water coming from the pumping house in the end. Valves need to be used in these processes. However, the requirements for the selection of valves in different parts are quite different. The main difference is the diameter, type and control method of the valve.
 
Valves used for water making system in tap water factory

Valves used for obtaining raw water
Valves used for obtaining raw water have relatively large diameters. They don't need to be operated frequently. Most of them only need to be operated once a year or even several years. Therefore, they are always opened or closed. A manual valve is selected based on the control method, and it is a gate valve or a butterfly valve. The diameter for the gate valve or the butterfly valve is from 1200mm to 1600mm. And there are even valves with a diameter of 3000mm at some parts of the water inlet pipe.
 
Valves used for sedimentation tanks
Inlet valves, outlet valves and isolation valves are mainly used for sedimentation tanks. The outlet valve is basically opened and the isolation valve is normally closed. They are operated once a year. Therefore, manual gate valves are selected for these two kinds of valves. The specifications are between 2200×1800 and 1200×840. The inlet valve of the sedimentation tank is responsible for the important responsibility of water distribution. It requires frequent adjustments, reliable performance and installation before each sedimentation tank, and electric control valves with intelligent control systems are adopted. The inlet valve is the key to determine the amount of water and the balance of the system in the sedimentation tank. It is particularly important for the system where the water line is dynamically adjusted according to the amount of water discharged, and dynamic tracking and adjustment of the PID are also required. At this time, there are corresponding requirements of the full travel time, allowable start and stop frequency of the valve.