Matters needing attention in butterfly valve selection and purchase!
Butterfly valve design and selection
The following points should be paid attention to in the design and selection of butterfly valves:
- Handle butterfly valve and worm gear butterfly valve selection: According to engineering experience, handle type butterfly valve is recommended when the pipe diameter is less than DN100mm. If a handle butterfly valve is used for a large pipe diameter, the handle may not be able to be moved during switching due to rust and insufficient operating space during use;
When the pipe diameter is greater than or equal to DN100mm, it is recommended to use a worm gear drive butterfly valve.
The handle butterfly valve is cheaper than the worm gear butterfly valve and should be considered comprehensively in the selection project.
- Selection of flanged butterfly valve and wafer butterfly valve: According to engineering experience, on the premise of ensuring installation quality, it is recommended to use wafer butterfly valve with a pipe diameter less than or equal to DN300 and pressure less than 1.6MPa, which is cheap.
If the pipe diameter is larger than DN300, it is recommended to use a flanged butterfly valve. Wafer-type butterfly valve can also be used if the pressure is greater than DN300 and the pressure is less than 1.6MPa, but it is necessary to fully consider the installation level and system pressure to prevent leakage.
- When inquiring, it is necessary to clarify the material of each part of the valve, so as to avoid the price difference caused by different materials, which will affect the fairness of procurement. The main components of butterfly valve are valve body, valve body sealing ring (valve seat), valve plate, valve stem, valve stem bearing and valve stem seal.
- Common materials of valve body: gray cast iron material HT200 can be selected for nominal pressure less than or equal to PN10, and gray cast iron material should not be selected for nominal pressure greater than PN10. Ductile iron, carbon steel castings, and stainless steel castings can be selected.
- The common material of valve body sealing ring is EPDM rubber or nitrile nitrile rubber (good oil resistance).
- The common material of the valve stem is 45# steel chrome-plated or stainless steel (2Cr13), and stainless steel is recommended.
- The common material of the valve plate is chrome-plated ductile iron or stainless steel (304). Stainless steel is recommended. After long-term operation of the water system, rust will accumulate on the valve plate, affecting the switch and sealing.
VALTECCN valve tells you that the price of valves with different materials varies greatly. When purchasing, the material should be determined according to the pressure of the system, the level of operation management, and the importance of the valve. Determining the standards must be targeted. After the material standards are unified, it is convenient to compare and negotiate prices, and finally buy products with high cost performance.
VALTECCN valve helps its customers to select the right valve type according to the process requirements and the system needs of the butterfly valves.