Thanks to their coned-disc, spring-loaded seat design, and support ring which compensates for seat wear and pressure and temperature changes, 60 series ball valves are the epitome of reliability.
How Do They Work?
The support ring houses the seat and protects against premature wear and deformation while the coned-disc spring supplies a spring-load to the seat, generating a seat seal regardless of pressure changes. Additionally, it reduces seat wear from pressure surges.
Swagelok’s 60 Series ball valves have a two-piece, live-loaded chevron packing design which help support the axial load radially from the stem nut along the length of the chevron, minimizing the operating torque of the valve and neutralizing stem wear. Ultimately, this creates a tight seal of the stem and bonnet.
Under high pressure, the ball in a 60 Series valve is forced downstream which flexes the downstream seat and creates a seal. Simultaneously, this upstream seat also flexes with the ball movement to maintain a seal. As pressure forces the seat downstream, the seat spring compresses, reducing the force on the ball, limiting wear and extending the cycle life.
How It Compares to Conventional Designs?
Conventional packing designs require higher force for the packing to work, resulting in the axial load being transmitted with higher force and uneven distribution, thus creating unnecessary wear on the stem and lowering the cycle life. In conventional valve seat design, pressure acts on the full area of the inlet seal when valve shut off, which means the seats only support the inside of the ball. Due to the fact a portion of the seat exposed to the ball orifice is entirely unsupported on the inside, seat failure is likely to take place as a result of pressure deformation.