The internal design is very simple. Seals (A) are permanently bonded into the slips (B), which are mounted on a central plug.
In the open position, the slip seals are completely out of the flow. Turning the operator handwheel clockwise rotates the plug assembly 90 degrees to block flow.
During rotation, clearance is maintained between the seal and the valve body, allowing free movement and avoiding abrasion.
When the operator is turned further clockwise, the tapered plug begins to lower, forcing the slips against the body, initiating the verifiable seal.
Because the seals never drag in well-maintained valves, the valve requires less torque to cycle. In the closed position, the slip seals are expanded, compressing the slip seals until metal-to-metal seating is affected.
Because it is mechanical, the Twin Seal valve doesn’t rely on line pressure differential to help make it seal. It even seals in vacuum service.
Simple, In-Line Field Maintenance Keeps Costs Down
A big advantage of the Twin Seal valve’s design is that it permits in-line servicing.
By simply removing the valve bonnet or lower plate (after the line is depressurized and drained), all models may be repaired from top or bottom without removing the valve from the line.
Cameron offers a slip exchange program.