Forged steel fixed ball valve is developed by the engineering and technical personnel of Gaopin company with more than 20 years of experience in the design and manufacture of high-pressure valves and adopting international new technical standards. It is mainly used for long-distance pipeline transportation of oil and natural gas and urban gas pipeline system. Due to the unique characteristics of valves used in long-distance pipelines, their ability to bear pipeline stress, safety, weather resistance and long-term reliability have been fully considered in the design;

The sealing and structural design are unique to Gaopin company. The operation modes include manual, worm and worm drive, pneumatic, electric, pneumatic / hydraulic linkage, electric / hydraulic linkage, and various special control forms.

Structural characteristics of forged steel ball valve:

1) The structure of forged steel valve is:

The valve body is made of forged steel, which can ensure sufficient strength and rigidity under the maximum rated working pressure, without the inherent defects of castings. Valve internals are carefully designed and selected to ensure reliability under various working conditions. The sufficient wall thickness of the split valve and the use of the highest strength connecting bolts are conducive to the maintenance of the valve and are sufficient to bear the stress of the pipeline.

2) Low operating torque:

The ball is a fixed ball, which is grinded, polished and hardened by the envelope grinding ball process and separated from the valve rod; The valve rod is a slender shaft, and its surface is hardened; The axial load of the ball is transmitted to the valve body through two large self-lubricating sliding bearings, so it is wear-resistant, flexible in operation and low in torque.

3) Advanced ball fixing method:

The ball is fixed on the valve body through two symmetrical bearing seats up and down, and the valve body bears the axial load of the ball. Therefore, the valve rod separated from the ball does not bear the bending load, realizing pure torque operation; At the same time, the axial load of the sphere is closer to the center, the acting radius is reduced, and the position of the bearing seat is close to the outer diameter of the pipe, so the stress condition is improved, the service life is longer, and the seal is more reliable.

4) Reliable sealing:

The valve sealing type is completed by the components of soft seal and metal support ring; The valve seat seal is a combination of rubber soft seal and metal seal structure, which is especially suitable for the harsh working conditions of dusty natural gas and sandy crude oil. The bearing ring of the valve seat is floating axially. The low-pressure sealing of the valve seat is realized by spring preloading, and the piston effect of the valve seat is reasonably designed to realize the high-pressure sealing by cutting off its own pressure, so as to achieve the purpose of cutting off the medium. At the same time, the fireproof sealing ring is designed to realize the sealing under the condition of fire.

5) Principle of valve seat piston effect:

The sealing principle of ball valve (non mandatory sealing) depends on the pressure of the medium itself to realize sealing, and the way adopted is usually the principle of piston effect; The valve seat sealing structure can be divided into single piston effect and double piston effect. When the upstream and downstream valve seats are both single piston effect and double piston effect, the ball valve is the upstream seal and the downstream self pressure relief; When the upstream and downstream valve seats are double piston effect, the ball valve is sealed by the upstream and downstream valve seats at the same time, and the sealing reliability is greatly improved. However, if it is used for liquid medium, an automatic pressure relief valve must be installed on the valve body. The sealing structure with single piston upstream (upstream self pressure relief) and double piston downstream can be adopted. At this time, the valve has the requirements of installation direction.

6) Emergency seal:

The valve rod / gland and the supporting part of the valve seat of the side valve body are designed with grease injection holes, and grease injection valves are installed. If the valve rod or valve seat seal is damaged and causes leakage, sealing grease can be used to realize secondary sealing. Each grease filling valve is equipped with a built-in check valve to prevent the sealing grease from overflowing under the action of the medium. The end of the grease filling valve is a quick link connector of the grease gun.

7) Double block and bleed (DBB)

When the ball is in the fully open or fully closed position, the medium in the cavity of the valve body can be discharged through the blowdown and venting device. At the same time, the overpressure in the cavity of the valve can be discharged to the low-pressure end by the free relief valve seat.

8) Venting device:

The upper part of the valve body is processed with a NPT vent hole. The vent hole is installed with a vent valve after the pressure test of the valve body. The middle cavity of the valve body can be vented and cleaned during the operation of the valve.

9) Fire protection design:

The valve design meets the requirements of API 6fa/api 607 standards, and has passed the fire test, which proves that it meets the requirements.

10) Anti static design:

Static electricity generated by friction between metal and plastic or rubber is very dangerous for transporting flammable and explosive media. Therefore, for the conductivity between technical parts (such as valve body, ball, valve seat support ring, valve stem) isolated by plastic or rubber seals, stainless steel springs are used to ensure the review of the provisions of BS5351.

11) Material selection:

The material selection of valve parts shall be reviewed according to the requirements of API6D, ASTM, ANSI and other specifications. The surface treatment of parts shall be carried out in different ways according to different working conditions. The requirements for vulcanization stress corrosion resistance shall be carried out according to the requirements of NACE Mr 0175.

12) Extended stem:

For directly buried installation valves, the valve stem can be extended, and the corresponding grease injection and drainage can be extended to the top of the generator for easy operation.

13) Various operation modes

The connecting plate of the valve and the driver complies with the provisions of ISO5211, which is convenient for the connection and exchange of various drivers. The common driving methods include manual, electric, pneumatic, pneumatic and hydraulic linkage, etc;