Globe valves and gate valves are common valves in the heating system, at the same time have the function of doing cut-off in the pipeline, the globe valve as a high resistance valves, usually used in the end of the heating system, assume the function of regulating and controlling, and gate valves in the heating system is more widely used, especially for the maintenance of the need to shut down the use of gate valves such as low resistance valves are more suitable. However, the two have some similarities in appearance, so there will be a lot of contact with the valve not many friends will be confused with the two. This article introduces the difference between gate valve and globe valve.
Applicable scene
Gate valve as a cut-off medium use, in the full open the whole flow straight through, usually applicable to not need to open and close often, and keep the gate fully open or fully closed conditions, not for use as a regulator or throttling. Globe valve can prevent the inflow of media or used to regulate the flow rate of media, usually applied to the system needs to be regulated or throttled when used.
Main differences
1. Structural differences
Gate valve is mainly composed of valve body, valve cover, valve stem, gate, valve seat, sealing filler and transmission device, switch, the gate moves up and down, the flow path in a horizontal line.
Globe valve is mainly composed of valve body, valve cover, valve stem, valve flap, valve seat, sealing filler and transmission device, switch, the valve flap upward movement, the water flow is low into the high and high.
2. Seal different
Gate valve sealing rely on the gate and the valve body for sealing, through the pressure of the medium so that the sealing surface of the pressure; globe valve is through the valve flap in the small trapezoidal side to achieve the closure of the seal, through the stem torque to the sealing surface of a downward pressure, relying on the pressure of the valve bar, so that the valve flap sealing surface and the sealing surface of the seat of the valve sealing surface compression, in the sealing force of the globe valve is higher than the gate valve. The two sealing contact area is different, globe valve in the case of all closed, the valve will be in contact with the sealing surface to each other, the contact area is only the trapezoidal side and the contact surface of the valve flap, as can be seen through the figure above, the contact between them is very small, the amount of slip is also small; while the gate valve in the case of all closed, the need for rafts and the valve body all in contact with the sealing contact area is larger, the relative amount of slippage is larger. As the sealing contact area of the gate valve is larger, when the medium through the globe valve, for the sealing surface of the wear and tear is greater, when the water quality contains sediment, iron filings, the sealing surface is susceptible to erosion and abrasion, the sealing effect will be greatly affected, especially when the valve is not completely closed, the medium of high-speed scouring of the sealing surface of the erosion of the huge, so that the valve sealing has a great reduction. The globe valve because of its sealing contact area is small, and the sealing surface in the centre of the fluid, the impact of water quality is small, the sealing surface is not easy to be eroded and scratched. Therefore, the sealing effect of the gate valve is not as good as the globe valve.
3. Flow direction and flow resistance
Gate valve belongs to the two-way valve, the installation of no import and export direction requirements, the medium can flow in both directions. And globe valve flow direction requirements, only allows fluid medium to a direction of flow. In the fully open state, the entire pipeline flow path of the gate valve is straight through, there is no obstruction, the medium of the operation of the pressure loss is minimal, so the flow resistance of the gate valve is very small; and globe valve due to its internal structure of the different, fully open, the entire pipeline is not straight through the pipeline flow path, the resistance is relatively large.