|Umbrella valves, How they work!
|Umbrella valves have been around for many years, Their applications include vessel vent valves such as for automotive fuel tanks, in- and outlet valves for piston- and diaphragm pumps, one-way check valves in (disposable) breathing masks, and numerous other fluid control functions in medical devices, home appliances, cars and toys.
Umbrella valves are elastomeric valve components that have a diaphragm shaped sealing disk or an umbrella shape if you like. These elastomeric components are used as sealing elements in backflow prevention devices or one-way valves or check valves, in vent valves or pressure relief valves and in metering valves. When mounted in a seat, the convex diaphragm flattens out against the valve seat and absorbs a certain amount of seat irregularities and creates a certain sealing force. The umbrella valve will allow forward flow once the head pressure creates enough force to lift the convex diaphragm from the seat and so it will allow flow at a predetermined pressure in one way and prevent back flow immediately in the opposite way. The main advantage compared to other types of valves such as spring loaded disc valves is that an umbrella valve uses its elastic material properties and its preloaded convex shape to create the sealing force against the seat and that it uses the central stem to hold the component in place so as to avoid the need for additional components such as a spring and the need for a central or circumferential disc positioner(s). This simplifies the design of the assembly and makes the valve adaptable to minimal space, reduces the number of pieces in a valve, simplifies assembly and last but not least is very cost effective.
|Other not less important benefits include:|
|- immediate positive seal,
- position independent,
- variable opening pressure trough seat thickness,
- high flow rate vs. package size,
- corrosion resistant,
- wear resistant
- and last but not least very cost effective.
Minivalve Umbrella Valves work with a specific seat design which needs to be integrated into the metal or plastic housing of the application. In order to find the proper seat design you may use our preferred seat design instructions and adapt them further to your specific needs. For example if your valve needs high flow then you make the flow orifices in the seat as large as possible even with slots in the shape of a banana. On the other hand if your valve has low flow or needs to withstand high backpressure, you need only to apply one or more small flow orifices and take care that the outside diameter of the flow surface area doesn't get too close to the edge of the umbrella in order to make sure that there is enough seat surface area to support the diaphragm under backpressure.
Minivalve Umbrella valves are available in various elastomeric material including medical and food grade silicone and hydrocarbon resistant fluorosilicone rubber to handle a broad range of media and temperatures.
Minivalve International is a niche company dedicated to the development, manufacturing and worldwide distribution of a broad variety of miniature, self-actuating valves and elastomeric valve components for OEMs. We have specialized in automatic high-volume manufacturing and offer our own range of standard Umbrella and duckbill valves from our catalog. They are supplied off the shelf in several sizes and materials. That means they are readily available in any quantity, from a few to millions of parts per year. We also develop customized valve solutions.