1. When purchasing, visually inspect the valve, and there shall be no blisters on the surface; The electroplated surface shall have uniform luster, and pay attention to defects such as peeling, cracking, carbonization, bottom exposure, peeling, black spots and obvious dents; The sprayed surface should be good. It is smooth and uniform, and there are no defects such as sagging and exposing the bottom. The above defects will directly affect the service life of the valve.
2. The pipe thread of the valve is connected with the pipe. When purchasing, visually inspect the thread surface for obvious defects, such as dents and broken teeth. It is important to note that the effective length of pipe threads and connecting members will affect the reliability of sealing. Gender, pay attention to the effective length of pipe thread when purchasing. Generally, the effective length of DN15 cylindrical pipe thread is about 10mm.
3. Gate valves and ball valves are usually marked with nominal pressure on their valve body or handle. When purchasing, you can choose according to your own needs.
4. When replacing the existing gate valve or ball valve, the structural length must be clear to avoid installation after purchase.
5. There are two kinds of pipe threads of triangular valve: internal thread and external thread, which can be purchased according to needs; It is also noted that there are some triangular valves made of zinc alloy on the market. The price of the valves is lower than that of ordinary products, but the corrosivity leads to damage. It should be purchased in conventional building materials stores and supermarkets, so as to ensure the quality of products.