Gate valves are essential components in fluid systems where full open or full close flow control is needed. Their design allows for minimal pressure drop when open and a reliable seal when closed, making them a top choice for various industries—from oil and gas to water treatment and manufacturing. But with different types of gate valves on the market, each suited for specific conditions, it’s important to understand their differences before making a selection. In this guide, we’ll explore seven widely used types of gate valves and explain how each works, where it performs best and what makes it unique.
1. Solid/Flexible Wedge Valve
The wedge gate valve gets its name from its wedge-shaped gate, which creates a tight mechanical seal when it’s forced between two inclined valve seats. This design offers excellent shutoff capabilities and is widely used in high-pressure and high-temperature systems. There are two main types of wedges: solid and flexible. Solid wedges are strong and ideal for clean fluids in systems with steady temperature and pressure. Flexible wedges are slightly elastic, allowing them to absorb thermal expansion and better accommodate minor misalignments or debris in the line.
This valve type is known for durability and consistent sealing, even in demanding applications like oil refineries, steam lines and chemical processing facilities. Because the wedge design relies on pressure to improve sealing, it’s especially effective in systems where complete shutoff is critical.
2. Parallel Slide Valve
Unlike the wedge type, the parallel gate valve uses two flat gates that slide vertically between parallel seats. These valves seal using a spreading mechanism, often with a spring or secondary element, which pushes the gates against the seats during closure. The parallel configuration reduces the amount of friction during operation and offers a lower torque requirement.
One major benefit of parallel gate valves is their ability to operate in systems with lower pressure and flow rates while still delivering reliable performance. They’re often chosen for their minimal pressure drop, thanks to a straight-through flow path. This makes them ideal for water distribution systems, irrigation setups, HVAC circuits and general utility services where efficiency and flow consistency are essential.
3. Solid Slab Valve
Slab gate valves, also known as through-conduit gate valves, feature a solid rectangular gate with a borehole in the middle. When the valve is fully open, this hole aligns with the pipeline, allowing fluids to pass through without restriction. This full-bore design eliminates turbulence, minimizes pressure drop and allows pipeline cleaning tools (pigs) to move through the system easily.
These valves are specifically engineered for high-pressure and high-volume systems, such as long-distance oil and gas pipelines. The flat slab design resists deformation and handles large pressure differentials effectively. Many slab gate valves include soft seats or floating seats that enhance sealing even when internal pressure is low. Their strong, corrosion-resistant build makes them a go-to option for critical infrastructure and hydrocarbon transport networks.
4. Knife Gate Valve
Knife gate valves are purpose-built for handling challenging fluids—such as thick slurries, pulp, powders or fibrous wastewater. The gate is designed with a sharpened edge that slices through suspended solids and ensures clean shutoff, even when flow media is dense or abrasive.
This valve’s body typically has a wide port and thin gate that moves vertically to open or close the valve. Its self-cleaning motion prevents build-up around the seat, making it ideal for processes where clogging is a concern. Knife gate valves come in wafer, lug or flanged end configurations and are easy to maintain. Industries like mining, pulp and paper, cement, food processing and wastewater treatment rely heavily on these valves for dependable performance in harsh environments.
5. Rising Stem Gate Valve
The rising stem gate valve provides a visual cue of the valve’s open or closed position. As the valve opens, the stem visibly moves upward, allowing operators to determine status at a glance without relying on guesswork or position indicators. This design is especially useful in applications where safety or operational clarity is essential.
Rising stem valves are built with externally threaded stems that are either inside or outside the bonnet. The Outside Screw and Yoke (OS&Y) design is most common in systems like fire protection and water treatment. Because the stem is outside the flow path, it remains clean and is easier to lubricate or inspect during maintenance. These valves are often preferred in regulated environments or facilities that require manual oversight and frequent inspections.
6. Non-Rising Stem Gate Valve
Non-rising stem gate valves keep the stem stationary as the valve operates. Instead of moving up or down, the stem rotates inside the valve body to raise or lower the gate internally. This compact design makes the valve ideal for underground installations, confined mechanical rooms and marine environments where vertical clearance is limited.
Although the stem doesn’t move externally, it engages directly with the gate inside the valve. Since it lacks visual position indicators, operators may need to install separate markers or sensors to monitor valve status. These valves are widely used in municipal water systems, underground fire mains, ships and other space-sensitive infrastructure.
7. Brass Gate Valve
Brass gate valves are made from a copper-zinc alloy that offers excellent corrosion resistance and mechanical strength. These valves are typically used in low-pressure and non-aggressive fluid systems, including domestic plumbing, air lines and small-scale commercial applications. Brass resists dezincification, making it a safe and long-lasting option for potable water.
This valve type is usually compact and lightweight, with either rising or non-rising stem configurations. They’re easy to install, affordable and low-maintenance—ideal for use in garden systems, HVAC lines and compressed air tools. While brass valves aren’t built for high-pressure or high-temperature systems, they provide reliable shutoff in everyday use cases.
Final Thoughts
Choosing the right gate valve from the different types of gate valve isn’t just about size and shape—it’s about matching the valve to the job. Every system has unique challenges, whether it’s fluid thickness, operating pressure, space constraints or temperature variation. That’s why understanding the full range of gate valve designs is so important.
If you need tight shutoff in a high-pressure system, a wedge or slab gate valve makes sense. For slurries or solids, go with a knife gate valve. Need something compact for underground use? Choose a non-rising stem valve. And for standard plumbing or low-cost setups, a brass gate valve will do the job.
Always factor in pressure ratings, media compatibility, environmental exposure and ease of maintenance when making your decision. The right valve will improve system performance, reduce downtime and extend your infrastructure’s service life.
1 Comment
Kyle
June 10, 2025nice blog