Appearance and Connection Dimensions
| Model | DN | L | D | D2 | nxd | D1 | C | H | H1 |
| PQ340X-10Q | 50 | 250 | 165 | 125 | 4-φ19 | 99 | 19 | 421 | 115 |
| 65 | 270 | 185 | 145 | 4-φ19 | 118 | 19 | 441 | 125 | |
| 80 | 280 | 200 | 160 | 8-φ19 | 132 | 19 | 480 | 140 | |
| 100 | 300 | 220 | 180 | 8-φ19 | 156 | 19 | 501 | 150 | |
| 125 | 325 | 250 | 210 | 8-φ19 | 184 | 19 | 608 | 190 | |
| 150 | 350 | 285 | 240 | 8-φ23 | 211 | 19 | 631 | 200 | |
| 200 | 400 | 340 | 295 | 8-φ23 | 266 | 20 | 713 | 240 | |
| 250 | 450 | 395 | 350 | 12-φ23 | 319 | 22 | 771 | 270 | |
| 300 | 500 | 445 | 400 | 12-φ23 | 370 | 24.5 | 859 | 300 | |
| 350 | 550 | 505 | 460 | 16-φ23 | 429 | 24.5 | 996 | 328 | |
| 400 | 600 | 565 | 515 | 16-φ28 | 480 | 24.5 | 1170 | 390 | |
| 450 | 650 | 615 | 565 | 20-φ28 | 530 | 25.5 | 1269 | 430 | |
| 500 | 700 | 670 | 620 | 20-φ28 | 582 | 26.5 | 1452 | 480 | |
| 600 | 800 | 780 | 725 | 20-φ31 | 682 | 30 | 1562 | 530 | |
| 700 | 900 | 895 | 840 | 24-φ31 | 794 | 32.5 | 1717 | 600 | |
| 800 | 1000 | 1015 | 950 | 24-φ34 | 901 | 35 | 2041 | 725 | |
| 900 | 1100 | 1115 | 1050 | 28-φ34 | 1001 | 37.5 | 2107 | 760 | |
| 1000 | 1200 | 1230 | 1160 | 28-φ37 | 1112 | 40 | 2292 | 845 | |
| 1200 | 1400 | 1455 | 1380 | 32-φ40 | 1328 | 45 | 2566 | 950 | |
| 1400 | 1600 | 1675 | 1590 | 36-φ43 | 1530 | 46 | 2935 | 1100 | |
| 1600 | 1800 | 1915 | 1820 | 40-φ49 | 1750 | 49 | 3340 | 1250 | |
| 1800 | 2000 | 2115 | 2020 | 44-φ49 | 1950 | 52 | 3750 | 1390 | |
| 2000 | 2200 | 2325 | 2230 | 48-φ49 | 2150 | 55 | 4000 | 1480 | |
| 2200 | 2400 | 2550 | 2440 | 52-φ56 | 2370 | 58 | 4460 | 1600 |
Main Part Materials
| Part Name | Part Material |
| Valve Body | QT450-10 |
| Eccentric Hemisphere | QT450-10 |
| Valve Stem | 20Cr13 |
| Valve Seat | 304 |
| Ball Crown | 0Cr18Ni9 |
| Shaft Sleeve | H62 |
| Disc Seal Ring | EPDM |
Eccentric Hemisphere Valve Structure Diagram
The eccentric hemisphere valve belongs to the shut-off valve category, mainly used to cut off and connect the medium flow in pipelines. Due to its strong flow capacity, low flow resistance, quick opening and closing, long service life, bidirectional sealing, online maintenance, and cutting functions, it has obvious advantages over gate valves, globe valves, butterfly valves, and ball valves in shut-off valve categories, especially under conditions of high flow velocity, large diameter, high pressure, sewage, and sediment. It is an upgraded product widely used in many water plants, power stations, steelmaking, mining, and large water conveyance projects.
Technical Specifications
| Model | PQ340X-10Q | PQ340X-16Q | |
| Nominal Pressure (MPa) | 1.0 | 1.6 | |
| Test Pressure (MPa) | Strength (Water) | 1.5 | 2.4 |
| Sealing (Water) | 1.1 | 1.76 | |
| Applicable Temperature (℃) | 0℃~80℃ | ||
| Applicable Medium | Clean Water, Sewage | ||
Flow Resistance Curve
Principle
The eccentric hemisphere valve mainly consists of valve body, eccentric hemisphere, valve cover, valve seat, ball crown, long eccentric valve stem, short eccentric valve stem, shaft sleeve, and other components. The driving methods include worm gear drive, electric drive, and hydraulic drive. The driving device drives the long eccentric valve stem to control the eccentric hemisphere to rotate 90° for opening and closing.
Selection
◆ According to different sealing surfaces, valves can be divided into soft-hard sealing and metal hard sealing types.
◆ Soft-hard sealing hemisphere valve: used for strict conditions such as sewage treatment, pulp, and urban heating.
◆ Metal hard sealing hemisphere valve: depending on different alloy welding, the bimetallic sealing surface can be used for wear resistance, corrosion resistance, high temperature resistance, and strict sealing requirements.
◆ Due to different structures, customers can choose vertical or horizontal types according to site conditions or space. Vertical type is recommended first if space allows.
Structural Features
◆ Reliable automatic compensation sealing: When the valve is under positive pressure, using the principle of eccentricity, the ball and valve seat become tighter as it closes, ensuring good sealing. When under back pressure, the floating valve seat is pushed tightly against the ball by the medium, and the higher the pressure, the better the sealing effect; during long-term use, if the valve seat seal wears out, the valve seat is automatically pushed tightly against the ball by spring force, providing good compensation effect. (Figure A)
◆ Automatic cleaning and desilting function: The edge of the ball crown is equipped with a blade-like structure, which can not only scrape off medium dirt on the valve seat but also cut off debris carried by the medium. (Figure B)
◆ Resistant to sediment accumulation: The vertical eccentric hemisphere valve has both upper and lower valve stems in the middle of the flow path, preventing sediment accumulation on the valve stem. The horizontal eccentric hemisphere valve has a flat-bottom hemisphere design at the valve bottom, preventing sediment accumulation. (Figure C)
◆ Suitable for high flow velocity media: Because the ball is hidden on one side of the valve chamber forming a straight-through flow path with no flow resistance, and the sturdy eccentric crankshaft causes no vibration or noise in high flow velocity media. (Figure D)
◆ Low resistance and energy consumption: The straight-through full-channel wedge-type eccentric design structure allows the flow path to be completely unobstructed after opening, with flow resistance loss basically zero, saving a lot of energy.
◆ Low maintenance cost: When the valve leaks externally, the upper and lower eccentric crankshafts can be directly disassembled, and the O-ring seal can be replaced. When the valve leaks internally, the valve cover can be directly opened for online inspection and maintenance, effectively shortening maintenance time and reducing maintenance costs.
PQ340X-10Q-50-1800.00
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