Seat design is an important topic in the world of industrial ball valves. Not only are ball valves classified by their seat designs, but allowable leakage rates are solely dependent on the design of the seat. There are two classifications: soft seats made of non-metallic materials, and metal seats. Soft seats are the most prevalent and Milwaukee Valve offers innovative soft seat designs and materials to meet your various ball valve requirements.
Properly designed soft seat rings are very effective and produce leak-tight seals that are often referred to as
. Cantilever seat design is a good option when you want to reduce operating torque. Unlike "jam" seats, which produce a tight seal initially, but do not do well in situations producing wide pressure or temperature fluctuations, cantilever seats perform well in tough applications. Under high pressure conditions the ball will be pushed toward the seat, causing the seat to flex. This movement increases the sealing area between the ball and seat surface, thus increasing the sealing ability and reducing the pressure on the seat. This feature creates a lower and more consistent torque, preventing seat damage.
The addition of pressure equalizing grooves in the outside diameter of the seat allows the upstream seat to "move" with the ball, creating pressure equalization in the ball cavity area, and ultimately a longer valve life. This enables seat support in high-pressure differential application, and the added benefit of lower actuation costs. All Milwaukee Valve ball valve seats are encapsulated into circular recesses within the body and tailpiece which controls deformation of the seat during high to low pressure cycling.
The different seat designs are based on the material used to make the seat rings, and Milwaukee Valve has a wide offering of seat materials including PTFE, RPTFE, C-RPTFE, UHMWPE, PEEK, Delrin, and NXT75. These various seat materials give our valves a wide range of application uses. Please check out our
Seat Material Bulletin
for detailed information on each of these seat materials, and how they can work best for you.