1、 Basic Definition

Hard sealed wear-resistant ball valve is a ball valve that adopts a metal to metal sealing structure. Its core feature is that the sealing surfaces of the sphere and the valve seat are both made of metal or high hardness alloy materials, and are hardened through special processes such as supersonic spraying, hard alloy welding, nickel based alloy thermal spraying, etc., to achieve a sealing surface hardness of HRC60 or above, with a maximum of HRC74-78. On this basis, further structural optimization and wear-resistant design are carried out for extreme working conditions such as solid particles, high erosion, high temperature and high pressure, in order to achieve long-term reliable sealing and ultra long service life.

In short, it is a high-performance industrial valve that combines high hardness surface treatment and wear-resistant structure optimization on the basis of traditional hard sealed ball valves.

2、 Core structure

Table

Structural component description

The sphere is made of high-strength alloy steel and has undergone surface hardening treatment; Can be a floating ball or a fixed ball structure

The valve seat is made of metal material and is paired with the ball for grinding; Double seat (bidirectional sealing) structure is commonly used

Sealing method: metal hard sealing surface fitting+spring pre tightening (disc spring/plate spring)+fluid self reinforced sealing

In the fixed ball structure of the support structure, the ball is fixed by upper and lower support plates/support shafts, and the medium force is transmitted to the valve body rather than the valve stem

Connection methods include flange connection, butt welding connection, threaded connection, etc

Drive modes include manual, worm gear, pneumatic, electric, etc

Key structural features

Fixed spherical structure: The sphere is fixed inside the valve body and does not move with fluid pressure, ensuring stability and sealing.

Double sided sealing structure: The front and rear valve seats respectively form sealing pairs with the ball, and the inlet and outlet ends can be independently cut off.

Spring compensation mechanism: loaded by disc springs or leaf springs, it absorbs metal thermal expansion and prevents the ball and valve seat from expanding and getting stuck at high temperatures.

Scraper/self-cleaning structure: Stairs are made on both sides of the valve seat sealing surface to form a "double scraper" effect, which scrapes off particles attached to the ball during opening and closing to avoid damaging the sealing surface.

Dustproof structure: A dust-proof ring is installed at the valve stem to prevent solid particles from entering between the valve stem and valve body or inside the spring.

No cavity design: using C-shaped spheres or special flow channels to eliminate dead corners in the cavity and prevent slurry deposition.

Explosion proof valve stem and automatic pressure relief: valve stem head protrusion anti spray structure; Automatically release pressure when the pressure in the middle chamber rises abnormally.

3、 Sealing principle

Closed state: After the sphere rotates 90 °, the sealing surface of the sphere is tightly adhered to the sealing surface of the valve seat. Under the dual action of medium pressure and spring elastic force, the valve seat tightly presses the sphere, forming sufficient sealing pressure to achieve zero leakage.

Bidirectional sealing: The medium can apply pressure from any direction, and the valve seat can be pushed to press the ball tightly by the spring pre tightening and fluid self strengthening effect, and the inlet and outlet can be sealed.

High temperature compensation: Under high temperature conditions, the disc spring/plate spring structure absorbs thermal expansion deformation, ensuring that the ball and valve seat always maintain appropriate contact force and will not get stuck or leak due to thermal deformation.