In the ball valve industry, the most important components to seal the flow control system is the valve seat or seal face. The ball cooperates with the valve seat to achieve the seal. To meet different medium applications, we TEKO have developed several ball seat designs:
There are four types of ball valve seat
1. Soft seat: usually made of PTFE, RPTFE.
Advantage: since the seal is soft, it is easy to seal the fluid.
Disadvantage: if the fluid contains particles, the fluid may scratch the seat and cause damage.
In order to make a better and wider applications, we adds some element to modify the property of the PTFE seat to improve the hardness of the seat valve. The most used are two kinds: one is 25% carbon filled TPFE, black color; the other is SS filled TFE, grey color.
The advantage of the modify TFE material is that they can be used in higher temperature and is harder than the PTFE.
2. Fire safe seat
For the soft seat design, when fire occurs, the seal will be damaged and cause leakage. It is a big risk in some industry. So we have the fire safe design.
The fire safe design is as follow: there is a metal seal as a back-up secondary seal after the soft seat was damaged by the fire. After the fire, the soft seat are destroyed and the pressure push the ball against the fire safe lip to form metal to metal seal between the ball and the end cap fire safe lip.
3. Metal seat
There are two kinds of metal seat:
one is for large size soft seated, since the large size and ball is heavy, we need a metal seat to hold the soft ring to seal the fluid control system.
The other type is the truly metal to metal seat. The working principle is that the ball surface must be harder than the valve seat. Otherwise, the ball seal face will be scratched by the valve seat and cause leakage. And this kind of ball valve is very difficult to produce since any deviation on the ball or seat will cause leakage.
4.Lining Ball valve
For the most aggressive liquid, all the wet parts of valve are total lined with PTFE, PFA or other corrosion-resistant plastic.
Contact Person: Mr. Qipeng Chen