Specification :

Structure instruction
The product is designed and manufactured according to API Spec 6A “ Equipment Specification of Wellhead & X’ mas tree� and matched and interchangeable with any equipment which conforms to API 6A specification.
It creates the metal-to-metal seal by the pressure of the medium, the more the pressure is, the better the sealing effect is. Anytime the valve chamber can bear the pressure of the pipeline.
Valve body is machined of alloy steel forging with a stronger machinery properties and reliable performance.
Bonnet is connected with valve body with bolt, the seals include the sealing ring in the bonnet and the seal in the valve body;
The sealing face between valve core and valve body is welded with hard alloy with good abrasion resistance and anti-scour; the valve core is made of sulfide-resistance steel and the others adopt the process of hardness limit so the valve is able to be used in H2S condition.
The sealing-face of the valve core and the valve body is bead-welded with carbide, plus rubber seals, which has.
Operation instruction 
According to medium flow direction and by the flow direction indicating plate of the valve, the valve is installed. As positive flowing, The medium lifts the valve core and pass easily; If no positive medium pressure, valve core will self-shut off valve gate under self-weight and spring’ s tensile force, the back medium flowing stop.
Maintenances
The valve should be placed in the dry and airy room, and the inlet and outlet are sealed properly.
When the product is stored, the end flanges should be coated by oil against rust and dirt pollution.
The valve-core and the valve-seat must be examined every in a well time. The attrition rate will decide whether they are used by upset or are replaced.
Every seal element is replaced according to its examination.
There is a bit leak at a couple of seals of valve, and the sealing-face may have scratch or wear. Renovation will be done under face-off and ground finish.
As leak appears at the middle one of the valve bores, ring gasket should be replaced.
Parts List:
Item Component Qty Material
1 Body 1 4130
2 Disc 1 4130
3 Spring 1 1566
4 Bushing 1 Cu
5 O-Ring 2 NBR
6 Cover 1 4130
7 Stud 8 4130
8 Nut 8 5140