Summary of Functions
Triple eccentric metal seal butterfly valve designs in triple offset construction. The laminated seal or metal to metal seal makes the valve can be used for high temperature and high pressure working condition with long service life and energy saving. The triple eccentric metal seal butterfly valve is designed as a device to shut-off or regulate the working medium flow and widely installed in industrial pipelines with corrosive medium in metallurgy, iron and steel industry, power plant, petroleum, chemical industry, heat supply, inflammable gas, municipal water supply and drainage and etc.
As the latest technology achievement, triple eccentric butterfly valves provide a variety of connections to meet different face to face dimensions, such as wafer type, lug type, flanged type, ring-joint type, butt-welded type and jacketed type. It is suitable for acid, alkali and other corrosive medium at both high and low temperature due to wide material selection. Especially in large-diameter butterfly valve, it is continuously replacing the shut-off valves such as gate valve and ball valve with its advantage of zero leakage; meanwhile it is also continuously replacing the regulating valves such as globe valve with its excellent performance in regulation and control.
1. High performance triple eccentric patented sealing system.
– Laminated seat valve :Zero leakage sealing in bi-directional (As per DIN class I or ANSI Class VI).
– Integral seat valve: Bi-directional tight sealing ( As per ANSI Class V)
2. Excellent isolation and control function for gas and liquid.
3. Welded stainless steel or stellite body seat is specially designed for long service life.
4. No friction, wear and stagnation on the seat during the opening and closing.(Compression only)
5. The seal ring is easy to be replaced and adjusted.
6. Applicable to harsh working condition such as high temperature, high pressure and corrosive conditions.
7. The metal to metal seal ring is suitable for +600°C.
8. Self-compensating for temperature variances.
9. Low operation torque and reliable shut off torque.
10. Natural fire safe design.
11. The disc sealing ring compress along the circumference uniformly just as the effect of welding, to make the seal ring bend as spring. The resilient seal make sure the sealing performance is compliance with API 598 standard – Zero leakage for liquid or gas of the resilient seat valves. The resiliency of the seal makes the disc remain closing tight seal in the thermal cycle just as shown in below figure.
The Principe of Triple Eccentric
Eccentric 1: The shaft is placed behind the seat center line, so that the sealing ring can close
ly contact the whole seat.
Eccentric 2: The center line of shaft is deviated from the center line of the pipeline and valve,
so that it can be avoid the interference of valve opening and closing.
Eccentric 3: Seat cone axis is deviated from the centerline of the valve shaft, so the friction can be eliminated during the closing and opening process, and realizes the uniform compression sealing around the entire seat.
Laminated disc sealing
Seating force is generated by the torque during closing and works uniformly around the entire circumference. The resilient seal flexes and keeps the original shape of the valve seat. Compression force works uniformly along the circumference to realize two-way tightness shut off . The elasticity of the seal allows the valve body and disc to be contacted or expanded to avoid the risk of blockage due to temperature fluctuations. This sealing construction is able to be adjusted and aligned by itself.
There Are Various Sealing Construction To Meet Different Requirements.
1. Normal Type: The laminated sealing ring is fixed to the disc, easy to be replaced and adjusted, suitable for most of working condition.
2. Seal on body construction: The sealing ring is fixed to the body, during the opening, the sealing ring wont move with the disc, so that the sealing ring is not easy to be damaged. When the requested face to face is short, the seal on body construction is more suitable than seal on disc construction, for the seal on disc construction, and the thickness of disc is increased, and the outside surface of disc and retaining ring will stick out from the flange sealing surface.
3. Replaceable seat type: Both the seat on body and the sealing ring on disc can be replaceable, its easy to be repaired and replaced, the maintenance cost is reduced.