1. Manual Wafer Butterfly Valve Description：
A butterfly valve consists of body ,stem ,disc , actuator (manual actuator, worm-gear actuator , aerodynamic actuator or electric actuator) , and wafer type butterfly valve can implement the process for turning on turning off and regulating the flow by the circumrotation of stem and disc  that is droved by actuators.The disc is positioned in the center of the pipe, passing through the disc is a rod connected to an actuator on the outside of the valve. Rotating the actuator turns the disc either parallel or perpendicular to the flow. Unlike a ball valve, the disc is always present within the flow, therefore a pressure drop is always induced in the flow, regardless of valve position.
2.Main Features of the Manual Wafer Butterfly Valve 
1. Small in size and light in weight, easy instillation and maintenance. It can be mounted wherever needed
2. Simple and compact construction, quick 90 degrees on-off operation
3. Minimized operating torque, energy saving
4. Flow curve teeing to straight line, excellent regulation performance
5. Long service life, standing the test of tens of thousands opening/closing operations
6. Bubbles-tight sealing with no leakage under the pressure test
7. Wide selection of materials, applicable to various mediums
Nominal bore  mm 20 25 32 40 50 65 80 100 125 150 200
Valve core diameter  mm 10 12 15 20 25 32 40 50 65 80 100 125 150 200
Rated flux coefficient Kv 1.2 2 3.2 5 8 12 20 32 50 80 120 200 280 450
Nominal pressure Mpa 1.6 4 6.4
Match DKJ actuator specification DKZ-4100 DKZ-4200 DKZ-4300 DKZ-5400 DKZ-5500
3. Manual Wafer Butterfly Valve Images：
 
 

4.Manual Wafer Butterfly Valve  Specification：
Disc: DI/ALB/Rubber lined Disc/1.2501/1.4529/CF8/Hastelloy Alloy/Monel
Stem: 410/416/304/431/17-4PH/316/monel
Seat: NBR/Hypalon/EPDM/Neoprene/NR/Wear-Resistant EPDM/Viton/Silicon/Heat-Resistant EPDM/White EPDM/EPDM(NSF)/PTFE
Suitable temperature: -10~120
Medium: Fresh water, sewage, sea water, air, vapor, food, medicine, oils, alkalis, salt etc.
 Nominal Pressure:   PN10/PN16
Working Temperature : -45 C centigrade-+200C centigrade
Suitable Mediums :  Fresh water, Sewage, Sea water, Air, Oils, Acids, Alkalis, Salts, etc. 
5.FAQ
 1. What is manual wafer butterfly valve?
A: Wafer style is the more common of the two and is less expensive than the lug style. The wafer style butterfly valve is just about the standard. It ís so common that no one even bothers to use the word "wafer" when ordering a butterfly valve. It is taken for granted that if a butterfly valve is ordered, a wafer style will be received.
 
2. How about the Installation of the Wafer Style Butterfly Valve?
A: Butterfly valves are installed by inserting the valve between two flanges using bolts or studs and nuts to hold it all together. This type of installation, of course, makes it impossible to disconnect just one side of the piping system from the valve. That benefit is received using the lug style valve.
 
3. What is the working principle of manual wafer butterfly valve?
 A: A butterfly valve is from a family of valves called quarter-turn valves. In operation, the valve is fully open or closed when the disc is rotated a quarter turn. The "butterfly" is a metal disc mounted on a rod. When the valve is closed, the disc is turned so that it completely blocks off the passageway. When the valve is fully open, the disc is rotated a quarter turn so that it allows an almost unrestricted passage of the fluid. The valve may also be opened incrementally to throttle flow.