All Q&A Resources

The primary difference is the position of the shaft relative to the valve seat. One has a shaft centered in the middle of the disc, while the other uses a disc that is offset from the shaft.

Yes, valve size can significantly affect flow rate. However, valve size is only one factor that influences flow.

Full Port valves have an internal opening that closely matches the pipe's inside diameter, where as, Standard Port valves have a smaller internal opening than the pipe, creating a flow restriction.

Seat wear is typically caused by a combination of mechanical friction, frequent cycling, throttling service, abrasive media, chemical attack, excessive temperature, pressure fluctuations, and improper installation or alignment.

Depending on the application, a seat may last anywhere from a few months to several decades. The most accurate answer is that butterfly valve seat life depends far more on operating conditions than on the valve's age.

The primary difference is the sealing surface used to achieve shutoff. In general, resilient-seated valves prioritize tight shutoff and cost-effectiveness, while metal-seated valves prioritize durability and performance in demanding applications.

Yes, for occasional flow adjustment or moderate control applications, butterfly valves are often a practical solution but, not every butterfly valve is equally suited for throttling service.

Dead-end service refers to a piping condition where a valve is required to hold full system pressure from one side of the valve while the downstream piping, equipment, or flange has been removed.

A butterfly valve should generally be installed with the shaft in a horizontal position whenever practical. This orientation helps reduce seat wear, promotes more even disc loading, and can improve long-term performance in many applications.

The factory-calibrated spring pre-load for a control valve's pneumatic actuator, defined as a pressure range. Bench set helps ensure the valve responds correctly to its control signal and achieves the desired fail-safe position.

No, aluminum does not rust. Rust is a specific type of corrosion that occurs when iron or steel reacts with oxygen and moisture to form iron oxide. Because aluminum contains no significant iron, it cannot technically rust. However, aluminum can corrode. When exposed to air, aluminum quickly forms a thin, tightly bonded layer of aluminum oxide on its surface. This oxide layer helps protect the underlying metal and is one reason aluminum is widely used in industrial, marine, architectural, and process applications.

While both involve moving fluid or gas out of a space, a purge port is generally used for a deliberate process function, whereas a vent hole is usually used for pressure management, safety, or leakage indication.‍

Double block and bleed service is a piping and valve arrangement that uses two isolation barriers (the "double block") with a bleed valve or vent between them. The purpose is to positively isolate a section of piping or equipment and provide a way to verify that the isolation is holding by venting or draining the space between the two barriers.

A standardized measure of a valve's flow capacity. Engineers use Cv to compare valves and select one that can deliver the required flow while maintaining an acceptable pressure drop.

A pig device is a mechanical tool used in pipelines for various maintenance and operational purposes, such as cleaning, inspection, and product separation. The term "pig" is often believed to originate from the squealing noise that earlier models of these devices made as they moved through the pipeline, though some suggest that “PIG” is an acronym that stands for Pipeline Inspection Gauge.

A Severe or Critical Service Application refers to industrial, municipal, or commercial processes that involve extreme operating conditions that can compromise the safety, reliability, or efficiency of a system. These applications typically demand specialized equipment to withstand high levels of stress and perform under challenging conditions that may lie outside the range of typical products, test protocols and industry standards. - This can mean many things to many people, and one must take care to not simply throw money at a problem hoping it goes away.

A rotary actuator is a device that generates rotational motion to turn a shaft or mechanism, commonly used for quarter-turn valves like ball or butterfly valves. Think of a rotary actuator like a doorknob—when you turn it, it rotates around a central axis to open or close the door, just as a rotary actuator turns a valve stem or mechanism. A linear actuator is a device that produces straight-line motion to move a load along a single axis, often used for gate or globe valves requiring linear stem movement. A linear actuator is like a sliding drawer—when you pull or push it, the motion is straight and linear, just like moving a valve stem in or out to control flow.

A piggable valve is a type of valve that allows the free travel or passage of a device known as a pig. Pigs are mechanical tools inserted into a pipeline to perform tasks such as cleaning, inspection, or for separating media within a pipeline.

"WOG" stands for Water, Oil, and Gas, which is a rating that indicates the valve's maximum pressure handling capability for these three types of media. It is commonly expressed in terms of pounds per square inch (PSI) and is used to signify the valve's pressure tolerance under non-shock conditions.

Both are metal surface treatment processes commonly used on stainless steel. Pickling cleans and restores the surface, while passivation improves the surface's ability to resist corrosion.

Put simply, a throttling valve is not a type of valve, but rather, an industry term that refers to how a valve is used. The term throttling valve refers to any valve that's operated in a way that partially restricts the flow of media.

No, not all butterfly valves are bi-directional. Because bi-directional capability varies by valve design, it should never be assumed without verifying the manufacturer's documentation.