Advantages and Disadvantages of Gate Valves

As a commonly used pipeline shut-off valve, the advantages and disadvantages of gate valves stem from their structural design and working principle, which can be analyzed in terms of fluid resistance, operational convenience, and adaptability to application scenarios:

I. Main Advantages

1. Low flow resistance and low energy consumption

The interior of a gate valve body features a straight-through flow channel, allowing the medium to flow in a straight line without obvious bends or throttling structures. Therefore, the resistance loss of the fluid during passage is much lower than that of other valves, such as globe valves and check valves. This characteristic is particularly advantageous in large-diameter, long-distance transportation pipelines, as it can reduce the energy consumption of transfer pumps and lower long-term operating costs.

2. Bidirectional medium flow and flexible installation

The sealing structure of the gate valve's gate plate and valve seat is symmetrical, enabling the medium to flow in or out from either side of the valve. There is no need to distinguish between the inlet and outlet directions, and no deliberate alignment with the medium flow direction is required during installation. This greatly simplifies the pipeline construction process, especially in working conditions where the medium flow direction may change.

3. Relatively labor-saving opening and closing operations

When opening or closing a gate valve, the gate plate only moves up and down linearly along the valve stem axis. The contact area between the gate plate and the medium changes gradually during the operation, and the straight-through flow channel design reduces the pressure resistance of the medium on the gate plate. Compared with globe valves, less torque is required for operation, making manual operation easier.

II. Main Disadvantages

1. Long opening and closing stroke and low operational efficiency

A gate valve requires the gate plate to be fully lifted to the top of the valve cavity to achieve full opening, and fully lowered to fit the valve seat for full closing. Its opening and closing stroke is much longer than that of a globe valve. This results in a longer opening and closing time for gate valves, making them unable to meet the response speed requirements in emergency working conditions that require rapid pipeline shut-off or connection.

2. Easily worn sealing surfaces and high maintenance costs

The sealing of a gate valve relies on the tight fit between the gate plate and the valve seat. During opening and closing operations, there is relative sliding friction between the two. If the medium contains impurities, the wear of the sealing surfaces will be aggravated, leading to seal failure and medium leakage. Repairing worn sealing surfaces is difficult, and it is usually necessary to replace the entire gate plate or valve seat, resulting in high maintenance costs.

3. Large structural size and high requirements for installation space

To accommodate the lifting stroke of the gate plate, the height of the gate valve body is much greater than that of globe valves or ball valves of the same diameter. In scenarios with limited installation space, the arrangement of gate valves is significantly restricted, requiring additional space planning or the selection of special types.