Bellows seal cage control valve adopts the cage guided structure and pressure balanced plug. It is suitable for applications with relatively high differential pressure. The balanced seal ring replaces the upper seat to change the traditional cage double-seat structure into the cage single-seat structure. This improvement has greatly enhanced the shut-off class of the cage valve. The double sealing structure of the bellows and packing is adopted at the bonnet to thoroughly eliminate the possibility of media leaking to the outside. This kind of control valve is suitable for flow and pressure control of poisonous or precious media.
The plug makes use of the pressure balanced structure, the opening and closing force is low and the media under service conditions with high differential pressure can be controlled through relatively low actuator thrust. With such features as good sealing performance, high allowable differential pressure, cage guiding, large guiding area, good stability and compact structure, it can realize fast replacement of trims on the line with high maintenance efficiency, saving manpower and time. The balanced plug structure makes sure that the actuator thrust required is the lowest.
Parameters of control valves：
| Trim features： | cage guided balanced trim structure balanced seal ring structure |
| Body type： | straight-through type / angle type |
| Bonnet type： | bellows type |
| Flow characteristic： | equal percentage linear quick open |
| Size： | DN40-400（1.5”-16”） |
| Pressure class： | PN1.6、4.0、6.3Mpa（ANSI 150、300、600LB） |
| Leakage class： | ASME B16.104 Ⅴ（standard type metal seat） ASME B16.104 Ⅵ（shut-off soft seat） |
| Pipe connection type： | flange type butt welding type |
| Applicable temperature range： | -30C° ～ 260C° |
| Actuator type： | pneumatic diaphragm actuator pneumatic piston actuator electric actuator |
