Large diameter eccentric hemispherical valve

1. Main Features
(1) Eccentric design
● Single eccentric or double eccentric: The center of the ball deviates from the sealing surface of the valve seat, which reduces friction, reduces working torque, and prolongs the life of the seal.

● Zero-wear seal: The ball and valve seat do not make contact during opening and closing, and are only pressed when closing, which reduces wear.

(2) Top-mounted design
● Online Service: The valve cover is removable, and the internal components (such as ball, valve seat, and valve stem) can be inspected or replaced without removing the valve from the pipeline.

● Suitable for large diameters: DN300~DN2000 (or even larger) valves are difficult to repair, and the top-mounted design greatly reduces maintenance costs.

(3) Metal solid seal
● High temperature and high pressure resistance: The valve seat and ball are made of cemented carbide (such as stellite, tungsten carbide) or wear-resistant coated materials, suitable for high temperature (≤600°C) and high pressure (PN10~PN100) conditions.

● Anti-abrasion: Suitable for abrasive media containing particles, sludge, dust, etc. (such as coal powder, ore sludge, ash).

(4) Bi-directional sealing
● Forward/Reverse Seal: Some models support bi-directional pressure bearing and are independent of the flow direction of the medium.

(5) Low working torque
● Eccentric design reduces friction and can be used with worm drive, electric drive or hydraulic drive, suitable for automatic control.

2. Typical Applications
● Energy: Ash removal system in power plants, coal powder transportation.

● Metallurgical industry: blast furnace coal injection, ore sludge transportation.

● Petrochemicals: media containing particles (e.g., catalytic crackers).

● Wastewater treatment: sludge and sewer pipelines containing solid impurities.

● Main pipelines: large-diameter oil and gas pipelines (special design required).

3. Pickpoints
● Sealing level: hard seal (metal on metal) or soft seal (PTFE), selectable according to the characteristics of the medium.

● Drive Mode:

● Manual (worm gearbox, suitable for DN300~DN800)

● Electric/pneumatic (automatic control, recommended for DN800 and above)

● Hydraulic drive (ultra-large diameter, high pressure)

● Pressure level: PN10~PN100 or ANSI 150~600#

● Standard Specifications: API 6D, GB/T 26146, ISO 17292, etc.