D71XDouble eccentric flange butterfly valve is a kind of butterfly valve with soft sealing center line developed by industrial opening valve. The double eccentric flange butterfly valve has the advantages of compact structure, easy 90 ° rotary switch, reliable sealing and long service life. It is widely used in water supply and drainage of water plants, power plants, steel plants, papermaking, chemical industry, catering and other systems.

1. The valve adopts double eccentric structure, which has the sealing function of closing more tightly, and the sealing performance is reliable.
2. Stainless steel and NBR oil resistant rubber are used as sealing materials, which have long service life.
3. The rubber seal ring can be located on the valve body or butterfly plate. It can be used in different media for users to choose.
4. It can be used in different media as long as the sealing material of sealing valve seat is replaced.
5. The butterfly plate adopts frame structure with high strength, large flow area and small flow resistance.
6. The valve has the function of two-way sealing. It is not controlled by the flow direction of medium or affected by the space position. It can be installed in any direction.
7. The valve has unique structure, flexible operation, labor saving and convenience.

D71XMain technical parameters of clamp type rubber soft seal butterfly valve pn6 ～ PN16

Nominal diameterDN（mm)	50～2000		50～1600
Nominal pressurePN（Mpa)	0.6	1.0	1.6
Sealing test(Mpa)	0.66	1.1	1.76
strength test(Mpa)	0.9	1.5	2.4
Applicable temperature	Nitrile rubber: - 40 ℃ ~ 90 ℃ fluororubber: - 20 ℃ ~ 200 ℃
Applicable media	Water, air, natural gas, oil and weak corrosive fluid
Leakage rate	In accordance with GB / T13927-92
Driving mode	Worm gear drive, electric, pneumatic and hydraulic

D71XMaterials of main parts and components of clamp type rubber soft seal butterfly valve pn6 ～ PN16

Part name	Material Science
valve body	WCB、QT450-10、HT200、HT250
Disc	WCB、QT450-10、HT200、HT250
Valve shaft	2Cr13
seal ring	Oil resistant nitrile rubber
filler	Flexible graphite

D71XStandard for pn6 ～ PN16 of clamp type rubber soft seal butterfly valve

Manufacturing standards	GB/T 122387-89
Flange standard	GB9113-2000、GB17241.6-1998
Structural length standard	GB12221-89
Inspection standard	GB/T 13927-92

D71XStandard for pn6 ～ PN16 of clamp type rubber soft seal butterfly valve

Manufacturing standards	GB/T 122387-89
Flange standard	GB9113-2000、GB17241.6-1998
Structural length standard	GB12221-89
Inspection standard	GB/T 13927-92

1. Before installation, check whether the specification, pressure, temperature and corrosion resistance of butterfly valve meet the use requirements. Check whether the parts are damaged or loose.
2. The butterfly valve can be installed on the pipeline at any angle and should be closed; when welding the pipe flange, the valve sealing port should be blocked with a plate to prevent particles and sundries from damaging the sealing surface. After welding, take down the valve, clean the valve sealing surface and pipe cavity, and then install the fixed valve.
3. Please pay attention to the pressure bearing direction when the valve is closed.
4. Before installation, the sealing surface (sealing surface at both ends, sealing surface of butterfly plate and sealing surface of valve seat) shall be thoroughly cleaned to remove dust and dirt.
5. Before installation, the butterfly valve should be air tested, and the opening and closing position should be flexible, and the opening and closing position should be consistent with the position indicated by the pointer.
6. Manual operation, clockwise is off, counter clockwise is on, pointer indication is in place, it is not allowed to open and close the valve with additional force.
7. During the pressure test of the valve, it is not allowed to use single flange for installation and pressure test, but double flange installation and pressure test must be adopted. The test pressure shall comply with GB / T13927-92.
8. The bolts shall be tightened symmetrically and alternately instead of separately.
9. The limit screw has been adjusted before delivery, so it is not allowed to adjust it easily. If the configuration of driving device is electric or pneumatic, please refer to the manual of supporting drive device.
10. When the electric butterfly valve leaves the factory, the opening and closing stroke of the control mechanism has been adjusted. In order to prevent the wrong direction when the power supply is connected, the user should first manually open it to the half open position before connecting the power for the first time, and then press the inching switch to check that the direction of the indicator wheel is consistent with the opening direction of the valve.
11. If the valve is found to be open and closed abnormally, the cause shall be found out for repair and elimination, so as to prevent the valve from being damaged due to opening and closing by means of applying force.