III. Feature Description

(I) Triple – Offset Design

1. Unique Structural Principle
   The design principle of the triple – offset butterfly valve lies in that the axis of the valve stem is offset from both the center of the disc and the center of the valve body, and there is a certain eccentric angle between the conical axis of the disc sealing surface and the axis of the valve body passage. This unique triple – offset structural design enables the sealing surfaces of the disc and the seat to achieve a friction – free opening and closing action during the opening and closing process of the butterfly valve. When the butterfly valve opens, the disc first disengages from the seat sealing surface during rotation, avoiding wear between the sealing surfaces; when closing, the disc gradually approaches the seat, and when reaching a certain angle, the sealing surfaces fit closely to achieve reliable sealing.
2. Excellent Sealing Performance
   The triple – offset design greatly improves the sealing performance of the butterfly valve. In the closed state, the sealing between the disc and the seat is achieved through the close fit of the metal sealing surfaces, which can withstand high pressure and temperature and is not easily affected by medium scouring and wear. Even if the sealing surface is slightly worn during long – term use, good sealing effect can still be maintained through appropriate adjustment and maintenance. This high – sealing performance makes the triple – offset butterfly valve irreplaceable in some industrial occasions with extremely strict sealing requirements, such as gas transportation and toxic and harmful medium transportation.

(II) Operational Convenience

1. Low Operating Torque
   The TIANYU triple – offset butterfly valve fully considers the issue of operating torque during design and manufacturing. By optimizing the structural shape of the disc, the diameter and material of the valve stem, and the design of transmission components, the torque required during the operation of the butterfly valve is relatively low. Whether it is manual operation or equipped with electric, pneumatic, or hydraulic drive devices for automatic operation, the opening and closing of the valve can be easily achieved. During manual operation, the operator can complete the opening and closing actions of the valve with relatively small force through a handle or worm – gear transmission device, reducing labor intensity; in an automatic control system, the drive device can quickly respond to control signals to achieve precise control of the valve.
2. Quick Opening and Closing
   The opening and closing action of the butterfly valve is achieved by rotating the disc by 90°, which has a faster opening and closing speed compared to other types of valves such as gate valves and globe valves. This feature is of great significance in some industrial processes that require rapid cutting off or adjusting fluid flow. For example, in a fire – fighting system, when a fire occurs, the butterfly valve can quickly open to ensure the rapid supply of fire – fighting water; in the feeding and discharging control of chemical reaction kettles, the butterfly valve can quickly respond to process requirements to achieve precise material transportation.

(III) High Reliability and Long Service Life

1. Robust Structural Design
   The TIANYU triple – offset butterfly valve adopts a robust structural design, fully considering various operating conditions in industrial applications. The thickness of the valve body and disc is accurately calculated and designed, which can withstand high pressure and external loads, ensuring the structural integrity of the valve in complex working environments. At the same time, the connection between the valve stem and the disc adopts a high – strength structural design, which can effectively transmit the operating torque and avoid problems such as loosening and 断裂 during long – term use.
2. High – Quality Material Selection and Treatment
   In addition to the valve body using CF8M stainless steel material, key components such as the disc and seat also use high – quality metal materials and undergo special heat treatment and surface treatment processes. For example, the seat sealing surface is usually strengthened by surfacing with hard alloy to improve its hardness and wear resistance; the disc surface may be treated with hard chrome plating to enhance its corrosion resistance and wear resistance. These measures enable the valve to maintain good performance under various harsh operating conditions, extend the service life of the valve, reduce the frequency of maintenance and replacement, and lower the operating costs of enterprises.

IV. Manufacturing Process

(I) Raw Material Procurement and Inspection

(II) Valve Body Processing Technology

1. Precision Casting
   The valve body is usually manufactured using precision casting technology. By making high – precision molds, molten CF8M stainless steel liquid is poured into the molds, enabling the production of valve body blanks with complex shapes and high dimensional accuracy. During the casting process, casting process parameters such as pouring temperature and pouring speed are strictly controlled to reduce the generation of casting defects such as air holes, sand holes, and shrinkage porosity. After casting, the valve body blank undergoes preliminary cleaning and grinding to remove surface adherent sand and burrs.
2. Machining
   The cast valve body blank is machined to achieve the dimensional accuracy and surface quality required by the design. High – precision CNC machine tools are used to perform turning, milling, drilling, and other processing operations on various parts of the valve body. During processing, dimensional tolerances are strictly controlled according to the design drawings to ensure the accurate internal channel size of the valve body and the optimal fit accuracy with components such as the disc and seat. At the same time, the sealing surface of the valve body is finely ground and polished to improve the flatness and finish of the sealing surface, laying a foundation for achieving reliable sealing performance.

(III) Disc and Seat Manufacturing Process

1. Disc Manufacturing
   The manufacturing of the disc also focuses on material quality and processing accuracy. High – quality metal materials are selected and made into disc blanks through forging or casting processes. Then, through machining, the shape, sealing surface, and other parts of the disc are accurately processed. For discs with a hard – seal structure, the sealing surface requires special treatment, such as surfacing with hard alloy. During the surfacing process, welding process parameters are strictly controlled to ensure that the hard alloy layer has a uniform thickness, firm bonding, and ensures the dimensional accuracy and surface quality of the sealing surface. After surfacing, the sealing surface is precision – ground and polished to achieve an extremely low surface roughness, enabling good fit with the seat sealing surface.
2. Seat Manufacturing
   The seat is a key component for achieving the sealing of the butterfly valve. The seat material is usually selected from hard alloys or other high – performance metal materials that match the sealing surface of the disc. The manufacturing process of the seat includes blank processing, heat treatment, and sealing surface processing. In the blank processing stage, the seat blank is machined into a shape close to the design size through mechanical processing; then heat treatment is carried out to improve the hardness and wear resistance of the seat material; finally, the sealing surface of the seat is precision – ground and polished to achieve good cooperation with the disc sealing surface and optimal sealing effect.

(IV) Assembly and Inspection Process

1. Assembly Process
   Before valve assembly, all components are strictly cleaned and inspected to ensure no impurities, oil stains, or damage. According to the precise assembly sequence and process requirements, components such as the disc, seat, valve stem, and sealing ring are assembled. During the assembly process, professional assembly tools and equipment are used to strictly control the assembly gap and fit accuracy, ensuring that the connections between components are firm and the movement is flexible. For example, when installing the valve stem and disc, an appropriate interference fit or key connection method is used to ensure that the valve stem can accurately transmit the operating torque and enable the disc to rotate flexibly.
2. Inspection Process
   Each TIANYU triple – offset butterfly valve undergoes strict inspection before leaving the factory. The inspection items include appearance inspection, checking for defects, bumps, etc. on the valve surface; dimension inspection, using precision measuring instruments to measure the key dimensions of the valve to ensure compliance with design requirements; pressure testing, including strength testing and sealing testing. The strength test applies a pressure higher than the working pressure to the inside of the valve to check for deformation, leakage, etc. The sealing test applies a certain pressure on both sides of the valve in the closed state to detect whether the leakage of the sealing surface meets the standard requirements. In addition, for valves equipped with drive devices, the performance test of the drive device is also carried out to ensure that it can accurately and reliably control the opening and closing of the valve.