Manual valves - Manual valves in bulk - SIO

Manual Valves

SIO manufactures different types of high-quality manual valves. These valves are simply defined as valves that function using a manual operator, like a handlever or handwheel. They are ideally used when a straightline fluid flow is required and when minimum restriction is needed. They both allow and hinder the flow that passess through the valve either by opening or shutting the gate.

They are made primarily of a bonnet and body, with the closure factor attaching to a stem that retains contact with the handlever or handwheel. Manual valves come in different types including ball valves, butterfly valves, globe valves, and gate valves among others.

You can trust SIO to provide you with top-quality manual valves and even customization services to best meet your needs and specifications.

    High pressure ball valve forged steel

    What Is a Manual Valve?

    A manual valve is a valve that operates through the use of a manual operator, such as a hand lever or handwheel. It is mainly used to start and stop flow, while other valve designs can also be used for throttling.

    An ideal manual valve for on/off services allows flow to go directly through the body with a full-area closure device that has little to no pressure drop. Usually, a manual valve can function as a throttling valve when the manual operator is positioned in a midstroke manner.

    SIO offers a variety of manual valves, all of which exhibit optimum performance for on/off and throttling/controlling services.

    We manufacture ball valves, gate valves, globe valves, and butterfly valves made of durable materials and equipped with essential features to ensure they meet the different needs of industrial applications.

    Functions of Manual Valves

    A manual valve is an essential part of many machines that operate on a daily basis.

    It serves several functions depending on the application it is used for. These are the main functions of a manual valve:

    Start/Stop Valves

    A start/stop manual valve is used in systems that do not require throttling for the process flow. The valve fully opens to allow media passage and fully closes to obstruct it.

    Control/Throttle Valves

    A control or throttle valve is used for applications that need precise control on the capacity and speed of process media flowing through the system.

    Control Methods of Manual Valves

    The control method used depends on the application and function of the manual valve.

    Generally, there are two ways to control process flow through a manual valve:

    Linear Motion

    Linear motion uses a closure component that operates in a straight line to allow, stop, or control the flow. The closure component could be a rod, disc, or a flexible material, such as a diaphragm. It is used to:

    Rotary Motion

    Rotary motion allows a manual valve to rotate a disc through a circular or angular shaft extending across the diameter of an opening. Rotary motion allows a valve to fully open or close after turning the stem 90 degrees.

    Classifications of Manual Valves

    Depending on their design and function, manual valves are generally classified into four groups:

    Rotating Valve

    A rotating valve is a manual valve that uses a quarter-turn rotation to open or close. It has a flow path directly through the valve body and closure device with no right angle turns.

    The most common rotation valves include ball valves, butterfly valves and plug valves.

    Stopper Valve

    A stopper valve uses a circular and linear motion closure device that is perpendicular to the center of the piping. It has a globular body to guide the flow through the proper angle turn above or under the closure device.

    The most common stopper valves are globe valves and piston valves. Because of their proper angle turn, these valves take more pressure drop compared to other valve types.

    Sliding Valve

    A sliding valve is a manual valve with a flat perpendicular closure component that intersects the flow. Similar to a rotating valve, a sliding valve has a body that allows process media to flow directly. 

    The closure device slides down and acts as a barrier to fully close media flow. The most common sliding valves are gate valves and piston valves.

    Flexible Valve

    A flexible valve is a manual valve with an elastomeric or flexible closure device and a body that allows a direct flow. The closure device pushes against a highly-flexible elastomeric insert until it is against the bottom of the valve body.

    The most common flexible valves are diaphragm valves and pinch valves.

    Types of Valves That Can be Operated Manually

    A manual ball valve is a type of rotating valve excellent for shut-off applications as it provides a reliable bubble-tight sealing. It uses a ball that makes a 90-degree rotation through a handwheel or lever to open, block, or regulate the flow of gas, liquid, or liquid with suspended solids. Generally, a ball valve is used for on/off applications; however, depending on its design, it can also be used for basic throttling.

    A ball valve is flexible and can be made with different materials and design features. For example, a ball valve can be designed for high-pressure applications by making it with stainless steel and equipping it with design features to withstand high pressure. Excellent examples are a blow-out proof stem, anti-static device, and a fire-safe design.

    Because of its capacity to provide air-tight sealing, a ball valve is suitable for an array of industrial applications. It is commonly found in oil and gas industries, petrochemical industries, power generation, and more.

    A manual butterfly valve is a rotating valve that provides reliable throttling and shut-off services. It is easy to operate and use a hand lever or gear to change the position of the disc, commonly known as the butterfly. The butterfly is perpendicular to the media flow when in a closed position and aligned with the flow when in an open position.

    A manual butterfly valve is used in different applications and to withstand complex conditions. It is made with materials and features to function optimally. For example, a high-performance butterfly valve is made of carbon steel with an EPDM seat to endure corrosion and abrasion present in chemicals found in petrochemical applications.

    Since it provides accurate control of process flow, a butterfly valve is widely used in industrial applications, such as chlorine processing, fuel handling systems, wastewater treatment, power generation, and other services in oil and gas and chemical industries.


    3. Plug Valve

    A manual plug valve is a quarter-turn valve primarily used for on/off applications. It has a solid tapered or cylindrical plug that rotates inside the body to control the media flowing through the valve. The plug may have one or more hollow passages going sideways so that media can flow through the plug easily when the valve is open.

    A plug valve is capable of handling different media types, such as gas, liquid, fuel, condensate, slurries, and more. Because of this, it is commonly used for applications in oil and gas industries, chemical industries, pipelines, and power generation.

    A manual globe valve is a type of stopper valve primarily used to stop, start, and regulate media flow. The disc moves perpendicular to the seat and can completely open the flowpath and completely close it. It is used for isolation and throttling services and is widely used in applications where the pressure drop does not have a significant effect.

    A positive shut-off is achieved by moving the disc against the flow stream instead of across it (as in the case of other valves). The flow through this valve type includes changes in direction that causes a higher resistance in flow. When there is high resistance, there will also be a high pressure drop. A globe valve is suitable for high-pressure applications involving steam.

    Since it is excellent for high-pressure systems, a globe valve is commonly used in fuel oil systems, cooling water systems, boiler drains and vents, feedwater, chemical feeds, and more.

    Cast steel gate valve

    5. Gate Valve

    A manual gate valve is a type of sliding valve mainly used to stop and start media flow. It is fully opened when the disc is removed from the flow. When it slides down through a manual lever or wheel, it provides a complete shut-off, fully blocking the flow from passing through.

    Since it is a reliable isolation valve, a gate valve is used in various applications in oil and gas industries, marine, pharmaceuticals, and water and wastewater treatment industries. It is capable of handling different properties of liquids, such as slurries, heavy oils, varnishes, creams, and other non-flammable viscous fluids.

    6. Diaphragm Valve

    A manual diaphragm valve is made up of a body with two or more ports, an elastomeric disc, and a seat, also known as a “weir” or “saddle.” This manual valve got its name from its flexible disc, better known as the diaphragm, that comes into contact with the valve seat found above the body to achieve a positive seal.

    The diaphragm is connected to a compressor through a stud forged into the diaphragm. To allow flow passage, the compressor moves up through the valve stem, while to stop flow, the compressor goes down until the diaphragm is pressed against the bottom of the valve.

    A diaphragm valve exhibits leak-tight features which makes it well-suited for food processing, brewing systems, pharmaceutical processes, water systems, corrosive applications, radwaste systems in nuclear applications, and dirty water operations.

    straight-through valve

    7. Pinch Valve

    A manual pinch valve is a flexible valve used to stop, start, and throttle process media. It consists of any valve type with a flexible elastomeric body that can be pinched to close the valve and obstruct media flow.

    A pinch valve uses linear motion control and similar to a diaphragm valve, it has a flexible disc that achieves sealing when pressed against a compressor. The stem of this valve type is connected to a closure element, called a compressor, which is found directly above the disc. Turning the handwheel lowers the compressor pressing against the bottom to close the pinch valve.

    This manual valve has a straight-through design allowing it to achieve tight sealing, making it ideal for industrial and manufacturing applications. These include pharmaceutical processes, wastewater facilities, pulp and paper industries, and other applications that deal with corrosive and abrasive media, slurries, and other types of fluids.

    Manual needle valve

    8. Needle Valve

    A manual needle valve is mainly used to control flow rate accurately and to provide a positive shut-off. It is a sliding valve that has a long-threaded plunger and a slender tapered point that lowers down through the seat to obstruct flow.

    Rotating the threaded plunger allows the tapered point to be accurately distanced from the valve seat. This allows precise control of the needle valve to open and regulate media flow. The fine threading of the valve stem and the large seat area promote accurate resistance to flow pressure.

    Due to its accuracy in controlling the flow rate, a manual needle valve is widely used in gas and liquid applications, cooling systems, power generation plants, and instrumentation control.

    Applications of Manual Valves

    1. Oil and Gas Industries

    Production process used manual valve to control the system

    Due to the increasing demand of oil and gas, industries that handle these process media continually engage in complex and severe applications. The operating conditions of these applications often involve high pressure and temperature, extremely low pressure, cryogenic applications, and hazardous substances that are corrosive and abrasive. To ensure success, oil and gas industries require manual valves that are highly reliable and capable of handling such harsh environments.

    SIO manufactures manual high-pressure ball valves that are excellent for applications in oil and gas industries. They are made with stainless steel or carbon steel, both of which are sturdy enough to withstand high pressure and corrosive and abrasive substances. They are equipped with an anti-static device, blowout proof stem, and a fire-safe design as protection against high pressure. They are also made with an extended stem designed to endure cryogenic temperatures.

    2. Chemical and Petrochemical Industries

    chemical industry

    Chemical and petrochemical industries often involve dangerous media that are corrosive and abrasive. Some of these are petroleum, ethylene, and propylene, all of which could lead to serious accidents when there is leakage. Because of this, applications involved in these industries require valves that can achieve an absolute seal and strong enough to withstand such substances even with continued use.

    We manufacture double offset butterfly valves that are specifically designed to endure such harsh working environments. They are designed to handle severe temperatures ranging from -4°F to 450°F and pressure ratings of 285 PSIG and 740 PSIG. They can be equipped with an EPDM valve seat capable of handling a variety of oils, fatty acids, chemicals, and solvents that are typically present in chemical and petrochemical applications.

    3. Food and Beverage Industries

    brewery interior, equipments

    Food beverage industries are rapidly growing industries that require highly-reliable parts and machines to ensure processing plants are running smoothly. The main challenges of these industries include safety and sanitary concerns, which require specific requirements from manual valves. Some of these include a reliable tight seal and the capacity to handle different media properties, such as oil, cream, grease, and other viscous liquids.

    SIO manual gate valves are well-fitted for the challenging working environments of food and beverage industries. They are made with either forged steel or cast steel so they can endure the different properties of media flow. They are capable of providing a positive shut-off to assure zero leakage and prevent contamination.

    4. Power Generation Plants

    Gas turbine electrical power plant with twilight

    Power generation plants involve many complicated applications to assure that the entire system operation is running smoothly. Some of these applications include chemical treatment, cooling systems, feed water, pollution control, steam turbine control systems, and so much more.

    SIO offers manual globe valves made from forged steel designed for pressure ratings from #150 to #2500. This makes our globe valves suitable for high-pressure steam and waterline, both of which are common in power generation plants. They are well-suited for throttling to control the flow rate accurately and shut-off services to ensure there is no leaking.


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