Valve Basics: A Beginner’s Guide to Industrial Valves

Valves are everywhere in industrial processes—controlling flow, isolating equipment, and protecting systems from overpressure. Yet for many engineers and technicians, the range of options can feel overwhelming. This guide covers the fundamentals of industrial valves, with a closer look at three widely used types: the válvula revestida, the válvula de aperto, and the válvula de esfera de aço inoxidável.

What Does a Valve Actually Do?

At its core, a valve is a mechanical device that regulates, directs, or controls the flow of a fluid by opening, closing, or partially obstructing a passageway. The main functions include:

• Isolamento ligado/desligado – stopping or starting flow completely
• Throttling – adjusting flow rate
• Non-return – preventing backflow
• Pressure control – relieving or reducing pressure

Choosing the right valve depends on the fluid, temperature, pressure, and the level of precision required.

The Two Big Families: Quarter-Turn and Multi-Turn

Valves fall into two broad categories based on how they operate.

Quarter-turn valves need only a 90-degree turn to go from fully open to fully closed. The válvula de esfera de aço inoxidável is a classic example. A bored ball rotates inside the body, aligning or blocking the flow path. Quarter-turn valves are fast, reliable, and easy to automate.

Multi-turn valves require several turns to open or close. Gate, globe, and diaphragm valves fall into this group. They offer finer throttling control but are slower to operate.

Key Valve Types and Where They Shine

Válvula de esfera de aço inoxidável

O válvula de esfera de aço inoxidável is one of the most popular choices for general isolation duties. Stainless steel offers excellent corrosion resistance, making it suitable for water, steam, oil, gas, and many chemicals. Ball valves provide tight shutoff, low pressure drop, and long service life. They are ideal for applications where quick, bubble-tight isolation is needed—but less suited for throttling, as partial opening can erode the seat.

Lined Valve

When the process fluid is highly corrosive—think acids, alkalis, or chlorinated media—a válvula revestida becomes essential. The interior surfaces are lined with PTFE, PFA, or similar fluoropolymers, protecting the metal body from chemical attack. A válvula revestida is commonly used in chemical processing, pharmaceutical production, and water treatment. The key advantage is combining the mechanical strength of metal with the chemical resistance of plastic. However, the lining is delicate, so careful installation and avoiding over-torquing are critical.

Válvula de aperto

For abrasive or slurries, the válvula de aperto is a workhorse. It works by pinching a flexible elastomeric sleeve with a mechanical or pneumatic actuator. The fluid only contacts the sleeve, never the valve body or mechanism. This makes the válvula de aperto perfect for mining, wastewater, and food processing—especially where solids, fibers, or abrasive particles would destroy a traditional metal seat. Pinch valves are also excellent for throttling and are naturally self-cleaning.

Materials Matter

Valve body material affects durability and compatibility:

• Latão – cheap, good for water and air, but limited chemical resistance
• Ferro fundido – strong and economical, used in water and steam
• Aço inoxidável – corrosion-resistant, ideal for chemicals and high-purity systems
• Plastic (PVC, CPVC, PVDF) – excellent for corrosive fluids at low temperatures

Trim and seat materials (the parts that actually touch the fluid) are equally important. A válvula de esfera de aço inoxidável with PTFE seats handles a wide range of media, while a válvula revestida uses a fluoropolymer lining to survive aggressive chemicals.

End Connections: How Valves Join the Pipe

Common connection types include:

• Rosqueado – simple, for small sizes and low pressure
• Flangeado – strong, for larger sizes and higher pressure
• Soldado – leak-proof, for critical or high-temperature service
• Clamped – easy to disassemble, common in sanitary applications

UM válvula de aperto often uses flanged or wafer connections, while a válvula de esfera de aço inoxidável is available in threaded, flanged, or welded ends.

Actuation: Manual vs. Automated

Manual valves use a handwheel, lever, or gear operator. Automated valves use electric, pneumatic, or hydraulic actuators for remote or programmed control. The válvula de esfera de aço inoxidável e válvula de aperto are both easily automated, which is why they appear frequently in process control loops.

Common Selection Mistakes

• Choosing a válvula revestida for high-pressure drop service without checking lining durability
• Using a válvula de esfera de aço inoxidável for throttling, causing seat erosion
• Installing a válvula de aperto where the sleeve material is incompatible with the fluid
• Ignoring temperature limits of elastomers and polymers