Floating ball valves are small in size, light weight, simple structure, good sealing, but ball workunder medium load to export all seals and therefore to consider sealing material can withstandsphere medium work loads.
High performance flexible floating seatDesign principle: lip shape seal technology
Applicable temperature: -46C- 250C
Applicable pressure: P.T.F.E:150Lb-600Lb P.T.F.E:150Lb-1500Lb
DEVLON:150Lb-2500Lb NYLON:150Lb-2500LbPEEK:150Lb-2500Lb NESPEL:150Lb-2500Lb
The rubber will occur large deformation under pressure to offset theroughness of metal surface, and can recover its original shape whenstress relief. This material is called as " Memory Property". We planto create a new seat material that can overcome the defects ofPTFE cold flow and thermal expansion and improve the memoryproperty. This sealing structure is called as Lucky Lip SealTechnology.
The lip shape seal seat has the advantages that its position will bechanged due to high temperature, which will form double pointssealing, sealing performance is more reliable.
There is a certain radian on the back side of the seat to prevent theright angle from being defomed, and it also can improve the lipshape seal seat elasticity.
The radian angle on the seat mainly avoid the higher extrusionstress occurred because of the deformation of the lip shape sealseat.
(1) As shown on the right: lt is a conventional packed type sealmethod, the strain stress of plastic between ball and seat or bodyand seat, of which contact areas size will decide valve sealing.
(2) As shown below figure: The improved sealing seat has theflowing characteristics: keep the ball in the center of body and alittle floatation; the lip area will occur a deformation afterassembling and obtain low pressure seal; the supporting point, incase of pressure and temperature increasing, to balance themedium force onto seat, this can prevent the cold flow happened.
The shape of unmounted lip shape seat cross section as shownfigure A, the completed shape as shown figure B, there are 4contact points, point B refers to sealing point contacting with ball,point A to sealing point contacting with ball, point C to supportingpoint contacting with ball while point to supporting point contactingwith ball.
The elasticity is reserved similar like spring due todeformation. When temperature or pressure increasing, to absorbin the elastic deformation energy; while decreasing, to obtainmemory property after release the elastic deformation energy.
(3) Grooving to protect the seat from being destroyed in the extrusion
(4) Up and bottom contact, to reserve material elasticity and obtain
(5) New type seat figure of Cheng Gong:process.
1. Avoid wrongly operate lever
Usually, to check valve operation status by checking the lever'sposition, it means open when the lever is parallel with the pipeline, andif vertical with the pipeline the valve is closed. The general shapeconnected between the lever and stem is flat rectangle which cancause to wrongly operation due to incorrect connection. However, theshape of floating ball valve from Cheng Gong is flat square, no wrongconnection will be happened and even no wrong operation.
2. Ball valve with locking device
Manual ball valve shall be locked in the full on or off position in order toprevent the valve from being operated improperly by non-employee.This also can reduce accident possibilities from pipeline shake or otherunexpected things, especially for the valve used in the services ofexplosive oil, chemicals and field environment.
3. Blow-out proof stem design
To prevent the stem from being blown out as a result of abnormallyrising of floating ball valve intemal pressure, a raised shoulder speciallydesigned on the bottom of the stem. And to eliminate the fires and stopthe leakage because the packings bumed out, thrust bearing mountedon the contact position between raised shoulder and stem, which cangenerate a reversed seal seat to prevent any leakage.
Subjected to the intemnal pressure, the general ball valve has thedisadvantages that the stem is easier to be blown out in the case ofpackings bumned out and the damage of gland and bolts. The fluid willspilt out lead to big accident happened, that is really forbidden.
The TFE/RPPL metal material bearing for ball valve canprevent the stem being jammed and easy operation.
4. Anti-static performance
To reduce static electricity which exists in ball, stem and TFE/RPPIseat, it is possible that the static charge will be discharge to bumableor explosive medium and creating spark, we require an anti-staticspring in the ball-stem connection and ball-body connection. Therefore,the build-up static electricity will be immediately connected to theground and ensure system safety.
5. Fire-proof protective structure
ChengGong company set a fire-proof seal ring to protect seat in caseof fire. The ball will be pushed into the downstream immediately underthe action of medium, it can help to seal once connected with eachothers to safeguard the system safety.
6. Special seat structure
According to our several years' experiences, we develop a kind ofdouble sealing seat with elasticity that hasanexcellent sealingperformance when used in the high pressure valve, low pressure valveand vacuum valve.
7. No external leakage body sealing structure
Since there is just a gasket between body and cover, it will leak incase of fire, high temperature, shake and uneven tighten torque. Inaddition to gasket for the floating ball valve, the contacts areas bodyand cover specially designed to metal seal and can avoid extemalleakage.