Design Features
Metalsin supplies EN 593 concentric flanged butterfly valves, which are worm gear operated and furnished with a pinless shaft. They have the following design characteristics:
- Concentric design: It features the valve disc and shaft (stem) that share the same centerline within the valve body, ensuring simple construction and efficient operation. This design is commonly used for low-pressure applications, with the soft seat material providing a reliable seal by compressing evenly around the disc. Its straightforward structure, low cost, and ease of maintenance make it ideal for waterworks application.
- Double flanged ends: It features integral flanges on both ends of the valve body, allowing it to be securely bolted between two pipe flanges. It has larger face-to-face dimensions compared to wafer or lug type butterfly valves. This design provides robust support, precise alignment, and reliable sealing, making it ideal for higher-pressure, higher-stress applications.
EN 593 concentric BFV, flanged, worm gear operated. DN1200 PN10, supplied to Jeddah, Saudi Arabia.
- Pinless shaft: By eliminating the pin connection between the shaft and disc, it avoids issues like pin corrosion, loosening, or breakage, enhancing sealing performance and reliability. The pinless design also reduces flow resistance and prevents medium buildup. Additionally, its simpler structure allows for easier installation and maintenance, lowering operational and maintenance costs.
- Splined joint: The shaft and disc of the pinless butterfly valve are connected using a spline connection. The splined joint between the shaft and disc of a butterfly valve is a robust and precise method for torque transmission. By interlocking external splines on the shaft with internal splines in the disc, it ensures efficient load distribution, high mechanical strength, and excellent alignment, reducing wear and prolonging the valve’s service life. It is ideal for high-pressure and large-diameter valves, offering durability, easy maintenance, and precise control in demanding environments.
Technical Specifications
Technical drawing for worm gear operated concentric flanged butterfly valve with a pinless shaft, which is joined to the disc with the splined connection.
Main Part | Material Specification |
Body | Ductile Iron
EN 1563 GJS-450-10 |
Disc | Ductile Iron
EN 1563 GJS-450-10 |
Seat Ring | EN 681 EPDM/BUNA-N |
Shaft | Stainless Steel
EN 10088 X20Cr13
EN 10088 X2CrNi18-9 |
Bushing | Brass
EN 12164 CuZn39Pb1 |
O-Ring | EN 681 BUNA-N |
Bottom Plate | Carbon Steel
EN 10025 S235JR |
*Main parts and material specification for double-flanged concentric butterfly valves.
DN | L
mm | A
mm | B
mm | C
mm |
350 | 190 | 230 | 330 | 210 |
400 | 216 | 325 | 365 | 285 |
450 | 222 | 345 | 400 | 300 |
500 | 229 | 385 | 450 | 300 |
600 | 267 | 450 | 520 | 300 |
700 | 292 | 490 | 585 | 500 |
750 | 318 | 525 | 630 | 500 |
800 | 318 | 540 | 610 | 505 |
900 | 330 | 615 | 690 | 500 |
1000 | 410 | 675 | 740 | 500 |
1050 | 410 | 705 | 775 | 500 |
1200 | 470 | 820 | 855 | 580 |
1300 | 530 | 880 | 935 | 580 |
1400 | 530 | 920 | 955 | 580 |
1500 | 600 | 1010 | 1070 | 580 |
1600 | 600 | 1070 | 1095 | 580 |
1800 | 670 | 1200 | 1280 | 700 |
2000 | 760 | 1325 | 1360 | 700 |
*Sizes (from DN350 to DN2000) and dimensions.
Design standard: EN 593; Double-flanged concentric type with pinless shaft (splined connected), rubber seated; Mounting flange according to ISO 5211; Flange drilling according to EN1092-1 PN10/PN16; Rated working pressure: 16 bar; Rated working temperature: -10°C~82°C.