Full Welded Forged Steel Ball Valve DN 18 inch

Product Description:

Design Features of full welded forged steel ball valve

The body of ball valve is full welded,selects high quality forged material,and adopts the advanced forged forming technology to form two semi-spheres which are welded into a whole in the middle of the body.This welding technology differentiates the ball valve form others,and makes the valve more spherically,so the valve structure is more compacter,lighter and stronger.Besides,the middle direct welding realize highly accurate valve body manufacturing,makes fully and completely sealing between the seat and ball.The full welding instead of bolts completely avoids the outside leakage,so ball valve is the ideal product for under-ground,offshore working platform and under-sea equipments.

Adopting fixed plates or trunnion to support the ball

The top and bottom of the ball is supported by upper and lower fixed plates or stem and trunnion,and the ball is accurately placed in the center of the ball valve to achieve complete seals and precise movements.When plate adopted,the force exerted by the medium to the ball is distributed via the plate to the left and right bodies,so that the stem does not bear the blending moment from the medium,but only the torque from the ball rotation during the opening/closing of the valve.The low-friction PTFE Teflon composite bearings installed between the ball axis and fixed plate and between the stem and the trunnion can absorb ball moving action caused by the pressure of the medium.This structure brings stable actions and easy operations for the ball valves,and the required operation torque can be reduced,so smaller actuators can be used,and the cost is cut down.

ball valve seat is floating structure,means the seat can move along the medium direction,so that the seat can fit against the ball all the time.
（Ⅰ）Double piston effect structure seat of full welded forged steel ball valve
Seat design is special double pistons effect structure,it can ensure the seal wherever the medium flows into the ball valve.

（Ⅱ）Seat multistage seal strucute of full welded forged steel ball valve
As following graphic instruction,on seat bearing ring,set two soft sealing rings(A and B)and metal sealing spherical surface which can seal with the ball.Seat ring A is spring loaded,which seals the surface with the ball tightly to the surface to form an initial seat;When there is pressure generated from medium,the piston force is generated to make seal ring A elastically deformed and seal ring B fit the surface of the ball surface due to the piston effect caused by area difference,thus the second seal forms.When the medium pressure is rising.It will generate huge pressure to seal ring A and seal ring B,so the two seals have a greater elastic deformation,then metal seal ball surface compact with ball surface to form the third level of metal to metal seal.

（Ⅲ）Secondary seat seal device of full welded forged steel ball valve
As the above graphic instruction,the secondary seal device(seat grease injection valve)can be chosen according to the actual working condition,medium requirement,seal requirement,etc.Seat ring grease injection valve is a one-way valve,installed on the body,which can prevent the leakage and inject grease under the outside force.When secondary seal is required,there is a grease injecting channel and hole on the seat ring.The grease can form a seal between the seat and the ball,and then stop the leakage.

Standards Applied of full welded forged steel ball valve：

FAQ of full welded forged steel ball valve:

Q1:I can’t find the type of steel check valve which I need. what can I do?

The chart above only lists out some common composition of steel check valve parts.We may provide other different parts material composition according to the customer's request or the actual valve working condition.

Q2:Which certification do your products pass?

  Our products are in accordance with ISO 9001、ISO 14001、API 6A、API 6D、TS CE、API607/6FA/BS6755.

Q3:How can I place an order?

  The only one thing you should do is to tell us the sepecification about type 、quantity and  mode of transportation, then we will send you quotation within 24 hours.