Whats The Rising Stem Ball Valve
Rising stem ball valve(also called Orbit Ball Valve) that’s same type as gate valve,and difference is ball valve that closure with a ball, but gate valve with wedge.the orbit ball valve mostly applications for that require zero leakage and frequent operation,and which almost used at critical isolation.
When an Orbit ball valve is closed,the core is mechanically wedged tightly against the seat,assuring positive shut-off. And when the orbit ball valve begins to open,the core tilts away from the seat and line flow passes uniformly around the core face.this eliminates the localized high velocity flow that typically creates uneven seat wear in ordinary ball,gate and plug valves.The core then rotates to the full open position.
As this kind of ball valve,the absence of seal rubbing during both opening and closing means easy, low torque valve operation and long term reliable performance. When valve leakage cannot be tolerated, the ORBIT operating principle can be relied upon to deliver a positive shut-off.
Advantage:
1, Rising stem ball valve.To achieve frictionless operation, the valve is opened by first lifting the stem to detach the ball from the seat and then driving the ball to the open position;When the valve is closed, the stem drives the ball around without touching the seat and then the stem drops and compresses the ball tightly against the seat.
2, the ball valve with fixed pivot structure of the ball valve, to ensure that the valve switch fast, low torque, easy to open and close.
3, the valve body structure adopts top-loading design, to ensure that the replacement and maintenance of internal parts of the valve can be carried out by removing the valve bonnet online repair, without the need to remove the valve from the pipeline.
4, to ensure that the valve has a long-term, continuous tight sealing characteristics.The sealing between the ball and the seat is independent of medium pressure to ensure that valve sealing is not affected by medium pressure fluctuations.
5, valve ball sealing surface and seat sealing surface adopt frictionless design to ensure the long life of the valve sealing body.Valve in the opening and closing process, valve ball sealing face and valve seat sealing face in the operation process always ensure no contact, to avoid mutual friction on the valve ball sealing face and valve seat sealing face damage and reduce the valve sealing performance and service life.
6. The seat shall be inserted into the body by mechanical interference and cold pressure, and the seat shall not be installed by welding, threading or adhesion.
7. Cut-off ball valve has seat scour free design.When opening and closing the valve, cut off the flow channel of the valve instantly fully open or completely closed, so that the valve in the switching process without high speed fluid local erosion seat sealing surface, so as to further improve the sealing life of the valve.
8. The sealing surface of valve ball adopts nickel base hard alloy, Hastelings alloy or other alloy surfacing welding, the minimum thickness of surfacing welding is not less than 1.5mm, in order to ensure the tightness and long sealing life of the valve under the most severe working conditions.
9, the valve has two-way sealing ability, can bear two-way pressure difference.
10. The fire resistance design of valves is implemented according to API 6FA and API 607 standards.All valves are fire - safe.
◆ The valve core and sealing surface of the valve seat are all metal sealing structure. In case of fire, the sealing can be guaranteed and leakage in the medium can be stopped.
◆ The middle flange is made of stainless steel and graphite wound gasket, which can meet the fire resistance requirements;
◆ The stuffing box is provided with flexible graphite packing, which can play the sealing effect when other packing loses effect due to fire and other reasons;Can meet the fire resistance requirements;
11, the valve stem through the stem nut, valve cover, valve body, ball core formed between the circuit continuous conduction, to achieve the anti-static effect.
12. In order to improve the reliability, safety and sealing ability of the valve and reduce the failure rate, the low-pressure air tightness of the valve does not depend on the seat spring to achieve.
13. Stem and ball position is controlled by stem guide pin and stem cut off. To ensure stability of valve operation, stem guide pin is a double guide pin, and the stem guide pin can be removed and replaced from the outside.
14. Use bolts or nuts to fix the handwheel or bearing. Do not use elastic clasp.
15. The installation size of the valve is the same as the existing valve, with good interchangeability.
Standard Features
No rub between sealing surfaces
Injectable packing
Single-seat design
Long life
Optimal flow: full port or reduced port openings give high CV figures
Top-entry design
Dual stem guides
Self-cleaning
Low-torque operation
Wear-resistant hard facing on core
Mechanical cam closure
