Ball valves play a critical role in controlling the flow of fluid and pressure within a pipeline, but their effectiveness and safety are only as good as the seat material used. Wear parts manufacturer Vesconite Bearings development engineer and consultant Cassandra Peens explains that choosing the right material for the ball valve seat is crucial for maintaining its sealing properties and dimensional stability, and increasing valve lifespans.

A ball valve consists of the body of the valve, the body cap, the stem, the hollow ball, and the round ball valve seat. The ball valve seat is responsible for sealing the fluid inside a pipeline and uniformly distributing the seating stress.

“The material needs to exhibit strong chemical resistance and temperature stability, ensuring it retains its shape under pressure to prevent any loss of seal. Dimensional stability is also key to preventing deformation under load,” she says.

Valves are used for the reliable, efficient and safe operation within a plant or pipeline, whether found in a petrochemical application where a leak could be environmentally devastating, or in a pharmaceutical laboratory where cleanliness and sanitation are critical.

Additionally, minimising the coefficient of friction is important to ensure smooth operation of the ball valve, reducing the torque needed to open and close the valve effectively. These factors collectively contribute to the reliable performance and longevity of the valve in various operational conditions, she explains.

Peens says that Vesconite meets these requirements, offering a unique combination of properties that make it exceptionally well-suited for the valve industry.

“Vesconite also has a lower coefficient of friction than traditional materials which means less torque is required to operate the valve—resulting in lower energy use and reduced wear on both the ball and the seat.”

“Vesconite is highly dimensionally stable and possesses excellent mechanical strength, allowing it to withstand significant loads and pressures without deforming. This ensures that the ball valve seat remains secure and continues to prevent leakage effectively,” she highlights.

Additionally, unlike many other materials, Vesconite exhibits minimal to no swelling when in contact with fluids, helping it maintain its shape and performance over time.

High-performance valves must withstand extreme conditions, including high pressures, frequent actuation and exposure to corrosive chemicals, water, grit and heat. Traditional materials such as bronze composites often require regular lubrication to minimise friction and wear, which can be a significant challenge in remote environments such as mines.

Moreover, moisture absorption can lead to swelling in materials such as nylon, while metals like bronze are prone to corrosion, which can result in premature valve failure, costly downtime and expensive repairs.

Another advantage of Vesconite is that it is easy to machine, which is especially important since valves come in a wide range of shapes and sizes and are often custom-made for specific applications.

“Vesconite components are designed to meet exact customer specifications, and the skilled team in our workshop ensures each part is precisely manufactured to deliver optimal performance,” Peens notes.

Reduced maintenance is also a key factor, with many valves installed in hard-to-reach places such as high up in pipelines or even underground, making maintenance both difficult and costly.

“With Vesconite’s low coefficient of friction and self-lubricating properties, we help reduce maintenance needs and downtime, which ultimately cuts the risk of production and income loss," she elaborates.

In safety-critical applications, it is especially important to minimise stick-slip and torque to ensure valves open quickly and reliably. Vesconite Bearings’ ability to custom machine ball valve components to suit specialised designs and applications further supports efficient, low-maintenance performance.