When selecting the flat gate valve, first understand the structure and characteristics of the flat gate valve. Flat gate valve is a kind of sliding valve with parallel gate, and the gate can be single gate or double gate with opening mechanism. The pressing force of the gate to the valve seat is controlled by the medium pressure acting on the floating gate or the floating valve seat. If it is a double-ram flat gate valve, the opening mechanism between the two rams can supplement this pressing force.
The selection of flat gate valve shall be comprehensively considered according to the actual application requirements and working conditions. For example, the oil and natural gas transmission pipeline needs to select the gate valve with single gate or double gate. If the pipeline needs to be cleaned, the rising stem gate valve with single gate or double gate with diversion hole can be selected. For the transmission pipeline and storage equipment of refined oil products, the gate valve with single gate or double gate without diversion hole can be selected.
In addition, knife-type gate valves shall be selected for pipelines with suspended particle media. For urban gas transmission pipeline, single-gate or double-gate soft seal rising stem gate valve can be selected. For urban tap water works, single-gate valve or double-gate gate valve with rising stem without diversion hole can be selected.
In addition to the medium and working condition, the material, structure, operation mode and other parameters of the flat gate valve shall also be considered. The material of the valve shall match the corrosive, oxidizing and abrasive properties of the medium, and the operating temperature and pressure range of the valve shall also be considered. The structure of the valve shall be selected according to the actual needs. For example, the rising stem flat gate valve is applicable to the situation where frequent operation or cleaning of the pipeline is required, while the non-rising stem flat gate valve is applicable to the situation where frequent operation or cleaning of the pipeline is not easy.
When selecting the flat gate valve, pay attention to the following parameters:
Flow coefficient: it reflects the flow capacity of the valve and needs to be selected according to the actual flow demand.
Leakage: the amount of medium leaking outward when the valve is closed. Proper leakage level shall be selected according to actual demand.
Flow characteristics: the flow characteristics of the medium shall be considered, such as whether it contains suspended particles and whether it is easy to scale, etc.
Operation mode: select proper operation modes according to actual demands, such as manual, electric, pneumatic, etc.
Repair and maintenance: consider the difficulty degree of valve repair and maintenance and whether special tools and equipment are required.
In a word, the selection of suitable flat gate valve needs to consider many aspects, including operating temperature and pressure range, structural form, material, driving mode and other parameters. Comprehensive consideration shall be carried out according to the specific application requirements and working conditions to ensure that the flat gate valve can meet the actual needs and play a good role.
