Double Flanged Spring Return Butterfly Valve

Size Flanged AS4087 PN16 50mm to 1200mm
Body FBE Coated Ductile Iron
Seat EPDM
Disc 316 Stainless Steel
Pressure Up to 16 BAR (depending upon size)
Actuation Spring Return Pneumatic

• What is a Spring Return Double Flanged Butterfly Valve?

  A spring return pneumatic double flanged butterfly valve is a butterfly valve that has integral flanges built into the body of the valve. It is designed to mate up to two flange faces in pipework. It has a direct mounted anodised aluminium spring return rack and pinion actuator fixed to the valve which conducts its 90 degree turn (open/close). The valve body is made of ductile iron (similar to cast iron but better advantages in terms of strength, elongation & life)  and has a center line design. The center line refers to the location of the disc and shaft in relation to the body (there are other kinds of butterfly valves such as double & triple offset) where it is precisely in the middle. These valves can have different seat materials but the most common would be EPDM but others such as FKM, NBR or PTFE are also used. This type of body has the added advantage that the disc of the valve will do most of its turn within its own body width whereas wafer or lugged the disc will turn mostly in the pipe. The actuator has a namur interface and position indicator. The actuator is considered fail safe as if air pressure is lost it will return to a fail safe position (either open or closed depending upon how it is set up) under torque given by the springs in the actuator.

• How does a Double Flanged Spring Return Pneumatic Butterfly Valve work?

  A spring return double flanged butterfly valve works by the shaft rotating 90 degrees which will take the position of the disc in the flow from open to close (or vice versa). When it is closed a seal will be formed between the disc and the seat effectively stopping the flow of the media. When it is opened again the disc comes away from the seat and when it is fully open sits side (smallest surface area facing) on to the direction of the upstream flow. This 90 degree turn is conducted by a spring return rack & pinion actuator which is connected to a shaft which in turn is mated to the disc by a spline. When the actuator is operated by a 5/2 valve (the most common we see is a 5/2 direct interfacing namur solenoid valve) the shaft will be rotated effectively turning the disc, switching it to its other state (either open or close). A 3/2 valve could be used instead which will operate one side of the pistons and rely on the spring to operate the other however we recommend a 5/2 to ensure clean air is only entering the actuator. If a 3/2 is used we would recommend a silencer is put into the unused port to help protect the actuator. Extras such as limit switch boxes and positioners can also be mounted directly to the actuator.

• How long will my Spring Return Double Flanged Butterfly Valve last?

  Like any valve this double flanged spring return unit depends upon the usage case of your butterfly valve, its environment, media and how many times it is cycled. For instance if it is on a clean wet media, in a clean environment and not cycled regularly the life will be decades. If it is on a corrosive media and in a dry application with a high cycle rate the life will be much shorter. We conduct regular lab testing and 6,000 cycles is a reasonable life cycle depending upon the application. The actuators life will depend upon how clean and dry the supply air is (the air that makes the actuator operate) however we regularly test these to over 800,000 cycles. Install a basic air filter if you are not sure about the quality of your air, we have pneumatic actuators that have been in operation for decades. The most common failure we see is due to dirty wet air being sent to the actuator.

• How do I install a Spring Return Pneumatic Double Flanged Butterfly Valve?

  These double flanged butterfly valves are designed to mate between two flanges. These will then be bolted together with the appropriate sized bolt and nut (varies depending upon size and flange standard). The seat of the valve also forms the gasket on the flanges so there is no need for a secondary gasket. The bolts should be tightened in a diagonal shape to avoid over tightening in one area. For a full list of instructions please visit our butterfly valve installation & maintenance guide. The spring return pneumatic actuator can accommodate a namur solenoid valve which is a very popular configuration (the 5/2 control valve bolts directly onto the actuator with an o-ring face seal on the back of the valve) or just a stand alone 5/2 valve. If you are using a stand alone 5/2 or 3/2 valve the air lines will need to be run from here into the ports/port on the actuator (remember the longer the run the slower the operation unless you use quick exhaust valves near the actuator).

• What are typical uses of a Spring Return Double Flanged Butterfly Valve?

  These double flanged units are common in the water industry especially because most of our models hold a Watermark and Standards mark approval. They are also used for general purpose applications as long as the media, temperature and pressure are compatible. As they are spring return they are usually used in fail safe applications where you would like the butterfly valve to return to a predetermined position (either open or close) if air is lost.

• How long will my product take to get to me? 

  This depends upon where you are based and the freight method chosen. If the express freight option is selected it is usually next day delivery to metropolitan areas in Australia for under 5kg. If free freight has been selected it will go by road freight which can be anywhere from 1 to 10 days depending upon your location. It usually averages 3 days.

• What warranty do I get?

  All of our products come standard with a 12 month warranty. The good news is we have very strict quality controls and all valves leave our warehouse tested (full material and testing certificates to API 598 are available) and inspected so there are rarely any issues. Also once your valve is in and operating it will most likely continue to do so for a very long time.