Manual Valves

Effectively regulate the flow of fluids with premium-quality manual valves from RS. Spanning several forms, including manual air valves and water valves, our range comprises many features, positions, actuator types, and build materials. With them, you can ensure that your flow systems benefit from the correct manual valve for the task at hand, driving safety, efficiency, and performance in kind.

We offer hundreds of manual valves, so use the filters on the page to find the exact manual valve required within your project specifications. Our products come from leading names in the market, including SMC Corporation, Dwyer Instruments, and Norgren, so you can purchase safely in the knowledge you will receive robust manual valves that can be confidently relied on.

View the range and find your part, or continue reading to learn more about manual valves, their differences, uses, and more. Contact our experts or visit the expert hub for more information and advice.

What are manual valves?

Manual valves precisely control or stop the movement of liquids, slurries, or gases along with a system. They are operated by hand and are available with an on-off function, a multiple-position configuration, or a throttling mechanism that allows the partial flow of the fluid to pass through.

Some manual valves use a solid or membranous mechanical gate to control flow, while others opt for a pneumatic actuator that uses pressurized air. Regardless of their function, however, most manual valves are designed to ensure minimal drops in pressure along with the system on which they are installed.

It’s important to utilize the right manual valves, as incorrect use can cause flow turbulence or damage the valve mechanism itself, such as using an on-off valve in a throttling position. To avoid this, before you purchase components understand your exact requirements, such as the direction of flow, flow control mechanism, and actuator type (such as foot presses, levers, and switches).

How do different manual valves work?

There are four main ways manual valve mechanisms operate – stopper, rotating, sliding, or flexible. These are used across the six main types of manual valves:

• Butterfly valves – Rotating butterfly valves feature a disk within the valve that is connected to the valve handle by a rod.

Fully closed with a 90-degree turn of the handle, these valves can be closed quickly, can withstand throttling, and can be used in lightweight or small-sized manual air valve and water valve designs as well as larger ones. Their disadvantages include an inability to handle slurries and poor cleanliness.

• Ball valves – Rotating ball valves are a powerful manual valve They include a ball-shaped interior part with a cylindrical bore opening running through it that, when rotated with a quick, 90-degree handle movement, securely stops the flow.

Full-bore ball valves have an opening that is the same size as the attached piping, while the opening in reduced bore ball valves has a smaller opening. The latter type can affect flow pressure, and neither is well-suited to throttling as the resultant pressure increase can deform the soft materials often used as a valve seat, causing leakage.

Ball valves are particularly well-suited to extreme flow volumes, pressures, and temperatures, and those that are corrosive but are not designed to handle slurries.

• Gate valves – With a sliding, up-down operation, gate valves feature a flat barrier that is inserted to stop the flow. These valves typically require multiple rotations of the valve handle to fully insert or retract the barrier.

Gate manual valves can be deformed when left partially open, so are not well-suited to throttling. However, when completely opened they offer little or no flow resistance, making them a good choice if you require a valve that doesn’t impact pressure along with the system, and they are effective at cutting through and stopping slurry flows.

• Diaphragm valves – With a flexible operation, diaphragm valves contain a stretchable membrane that is pushed down or pulled up to restrict flow. There are two types: weir and straight-through.

Weir-style diaphragm manual valves feature a bend or ‘saddle’ in the valve opening that a membrane is pushed down onto to create a seal. Straight-through-style valves, on the other hand, have a stopper above the membrane that is pushed down into a straight valve opening. Weir-style valves are suited to throttling, whereas straight-through mechanisms are better for on-off functionality.

Diaphragm valves have the added benefit of completely shielding the valve mechanism from the flow, making them a good choice for liquid flow applications. However, they do require regular maintenance due to the membrane or saddle becoming worn over time.

• Globe valve – Built with a stopper mechanism that is lifted up and down by a screw attached to the valve handle, globe valves are a good choice for throttling extreme temperature and pressure flows, given their hard-wearing design.

The trade-offs, however, are that cleanliness can be poor, the S or Y-shaped valve opening of this manual valve type limits the flow rate of the fluid and fully opening or closing the valve can require multiple rotations of the handle.

What are manual valves used for?

Manual valves are used across an extensive range of processes. Manufacturing, shipping, oil and gas, electricity generation, plumbing; any process that requires the control, stoppage, or diversion of a high-pressure liquid, slurry, or gas will typically require the use of one or more manual air valves or water valves.

In a 2020 study, their use was shown to improve energy use and the environmental quality of the flow substance, as well as reducing maintenance costs. And in research from 2019, their efficacy in a power generation scenario was similar to motorized valves.

Why you should choose RS for your manual valves

RS is one of North America’s largest distributors of authorized components. All our products are produced to the highest standards, in line with all relevant regulations. This means you can trust our manual valves to control flow efficiently and effectively.

Our manual valve range fulfills a range of functions, controlling the flow of liquids and slurries or, as is the case with manual air valves, gases. It encompasses components from a long list of trusted manufacturers including AVENTICS, RS PRO, and Metal Work Pneumatic. Whatever your project or pipeline, we stock multiple manual valve port and body sizes, mounting styles, series, and configurations, including lever, shut-off, foot, rotary, and many more.

For more information on our range of manual valves, please don’t hesitate to contact our specialists, or visit our expert hub.