According to material classification
According to the different working environments of the penstock, the penstock material is not the same. The penstock can be divided into the following types according to metal and non-metal materials:
1. Metal Material penstock: steel welded penstock (steel plate, stainless steel plate), cast iron penstock, cast steel penstock;
2. Non-metallic penstocks: wooden penstocks, nylon penstocks, cement penstocks.
At present, the most used in water conservancy and hydropower projects are cast iron penstocks, steel penstocks, and cement penstocks. The following is an analysis of the advantages and disadvantages of these three penstocks and how to choose them.
1）. Cast iron penstock
Advantages: corrosion resistance, good anti-corrosion performance, one-time casting, and installation molding, after finishing large-scale mechanical equipment, good sealing performance Low maintenance costs, often used in smaller channel projects.
Disadvantages: The cast iron penstock has a large labor intensity and processing workload, and the deadweight is relatively high, the cost is high, it is not impact-resistant, the water-stop performance is poor, and the cast iron penstock is easily damaged when the water pressure is high.
2）. Steel penstock
Advantages: lightweight, large carrying capacity, impact resistance, stable performance and quality, strict water stop, simple manufacturing and installation construction technology, short construction period, simple and convenient maintenance, and has a certain degree of earthquake resistance, which can reduce the investment in opening and closing equipment Etc.
Disadvantages: The steel penstock has poor anti-corrosion performance, requires regular maintenance, and has a relatively short service life.
3）. Cement penstock
Advantages: relatively simple production, low cost, suitable for small water conservancy projects in remote areas.
Disadvantages: The cement penstock has a certain degree of water permeability, the structure is poor in seismic performance, and its own weight is large. It increases the capacity of the opening and closing equipment. It is not recommended in modern water conservancy projects.
Precautions for the purchase of cast iron penstock
The use of cast iron penstocks has played an important role in many water conservancy projects, which has also enabled our water conservancy project business to obtain more new developments.
Since it is to be used for such water conservancy construction purposes, when purchasing a series of water conservancy machinery such as cast iron penstocks, we need to pay attention to more than just the basic aspects of quality and price.
As a cast iron penstock, the first thing we need is that it has good pressure resistance and can ensure its good working conditions under various impermanent water pressures. This is also an important factor that we must consider in order to better utilize the performance advantages of such facilities.
Secondly, there must be corresponding process guarantees for the sealing of cast iron penstocks. In many water conservancy construction processes, we need to perform operations such as water control and drainage. If the cast iron penstocks used do not have good sealing properties if. Then not only the quality of our entire project will be seriously affected, but it will also bring great obstacles to the actual operation and application.
In addition, in order to help us purchase equipment that is more in line with actual user needs when purchasing cast iron penstocks, we also need to refer to relevant environmental specifications and materials.
After purchasing the cast iron penstock, there is still an important point when using it. That is the anti-corrosion of cast iron penstocks. Corrosion is one of the main reasons for the damage of steel products. Cast iron penstocks are commonly used devices in water conservancy projects and are in contact with water for a long time. Therefore, we must take some measures to prevent the corrosion of cast iron penstocks. Anti-corrosion of cast iron penstocks The main methods are as follows.
1. Galvanize or spray zinc on the cast iron penstock. Because the chemical properties of zinc are more active than steel, when corrosion occurs, the first thing to be corroded is zinc, so as to protect the cast iron penstock. In this method, zinc will be corroded quickly. In practice, after we spray zinc There will be another coat of paint.
2. We can also change the nature of cast iron penstocks. When making cast iron penstocks, some elements with very low chemical activity can be added to steel, which can effectively achieve the anti-corrosion effect.
3. In practice, the price of galvanizing is relatively high. If it is unacceptable, spray rust removal and fluorocarbon coating can be used. This method is also effective.
4. Spray the rust-removing epoxy anti-corrosion paint after rust removal. In fact, from a practical point of view, this method should be very thorough.
In practical applications, we should learn more about the characteristics of some cast iron penstocks. In this way, whether it is used or maintained, it is very powerful for the cast iron penstock, which is beneficial to prolong the life of the cast iron penstock.
FCV Penstock processing picture
FCV is one of the best manufacturers and suppliers of large-diameter gates in China. Since its establishment in 1935, FCVAL has been a leading enterprise in the production of low-pressure valves in China. The factory has passed the DNV ISO9001 certification for more than 15 years. It can manufacture and produce penstocks with a diameter of DN5000mm (5mX5m) with a maximum head pressure of 50m. The product design covers GB, AWWAC501, BS7775, and other standards. Our company can provide penstocks design, production, or special customized production services according to your requirements. Welcome to contact us for more information or request a complete product catalog.
