Flanged Trunnion DBB Ball Valve
Double Block and Bleed Ball Valve main parameter
Nominal diameter : 4"-24" , 100mm-600mm
Nominal pressure : 1500LB-2500LB , 1.6Mpa-32Mpa
Connection type : Flange
Material :CS,SS
Driving means : worm gear , electric , pneumatic .
 
Flanged Trunnion DBB Ball Valve
Double Block and Bleed Ball Valve Technical standard
Design and manufacture : API 6D
Structural Length : ASME B16.10
Flange connection : ASME B16.5
Test and Check : AIP 598
 
Flanged Trunnion DBB Ball Valve
Double Block and Bleed Ball Valve features
1. Double Block and Bleed Ball Valves, Which is the ideal equipment in cutting off medium, are widely used in hydraulic system pipeline of power, petrochemical , metallurgy , marine , petroleum , natural gas , coal gas , pharmaceutical and other industries.
2. Double Block and Bleed Ball Valve is also called DBB ball valve , DBB ball valve is a new kind of valve, it has completely double balls to cut off medium, discharge pressure and loot , Designed for reducing weight and saving space, Simplified installation procedure ,Reduce pressure in a pipeline system, Convenient instrument cleaning and maintenance . it is not only sealing reliable, and also saving the cost of manufacturing.
 
Flanged Trunnion DBB Ball Valve
DBB Ball Valve  

Specifications
1.Anti-fire safe design.Anti-static device 
2.Free leakage of body Sealed construction 
3.Double block&bleed. 
4.Extension stem.
 
1.Bow-out proof stem

For the purpose of preventing the stem from flying off  resulting in abnormal rising of the inner pressure of valve,shoulder is fixed at the lower part of the stem.In addition,in order to prevent leakage resulting from burnout of packing set of the stem in a fire,thrust bearing is set at the contact position of the shoulder at lower part of the stem and valve body.Thus an inverse seal seat is formed which will prevent leakage and avoid accident.
 
2.Anti-fire safe design
 
When the trunnion ball valve be used normally,its sealed by seat and ball surface,seat retainer sealed by O-ring and body,this is soft sealed and reliable sealing.When the seat and O-ring are burnt,the seat retainer and body will be sealed by expanded graphite.Thus act anti-fire safe purpose.
 
3.Anti-static device
 
In order to prevent friction among ball,stem and PTFE that generates static electricity which may light the combustibles and explosives that cause an accident,in this ball valve,static-conduction spring is set between the stem and the ball,the stem and the body.Thus static electricity is conducted to ground and system safety is secured.
 
4.Free leakage of body Sealed construction
 
The connective position of valve body and bonnet is double sealed by gasket and O-ring,on this base,such factors as fire,high temperature,shock and uneven opening or closing of the torque all can't induce external leakage.
 
5.Low torque in operation
 
The self-lubricated bearings are installed at the friction of stem,resulting in wear resistance,fiexibility of operation and low torque.
 
6. Double block&bleed(DBB)
 
When ball is full open or close position,the transmitter substance in center cavity of body can be released by drainage and emptying devices.In addition,the over loaded pressure in the center cavity of valve can be  released to low pressure end by self relief seat.
 
7.Emergency sealing
 
Compound injection holes are designed and compound injection valves are installed at locations of stem/cap and body support of side valve.When sealing of stem or seat is damaged to induce leakage,the compound can be used to do the second time sealing.A concealed check valve is installed in side of each compound injection valve to prevent compound from out flowing due to the action of transmitter substance.The top of the compound injection valve is the connector for fast connection with compound injection gun.
 
8.Extension stem
 
For the underground installed valve,the stem can be lengthened and for the convenience of operation the corresponding compound injection nozzle and drainage valve can be extended to the top of valve.
 
9.Automatic body cavity relief
 
When the body pressure going up un-normally as the unstable factor,the trunnion ball valve downstream seat will be pushed by un-normally pressure,and the release theunnormal pressure automatically,it doesn't damage to the sealing of upstream seat.
 
10.Various driving types
 
The top pad of valve designed according to ISO 5211,which is convenient for connection and exchange of various drivers.The common driving types are manual,electrical,pneumatic and pneumatic/hydraulic.

Product parameter