Small Umbrella Valve, also known as Miniature Valve or Mini One Way Valve. Small Umbrella Valve has round diaphragm seals & seat for air or water pressure relief and backflow controls like Belleville valve, also have rubber stem and hooks for location. Miniature Umbrella check valve is an one way valve. Its shape like a mushroom. Umbrella Valve & Seals is mainly made from high-tensile solid silicone (HTV) or liquid silicone rubber (LSR) materials, also made from other rubber materials like Neoprene, EPDM, Fluorosilicone, FKM, FFKM, Nitriles etc.
Small Umbrella & Mushroom Check Valve Working Principle
Mini Umbrella Valves feature a ball or rounded shaped end which install easily into a mating plate or receptacle. Small Umbrella Valves allow flow in one direction and check flow in the opposite direction. Under specified pressure, the umbrella valve open and close automatically to control the fluid/air flow in one direction and prevent back flow. The automatic open normally affected by hardness of the silicone rubber material that used, the thickness of the umbrella part, the initial bearing strength of the sealing surface, and flowing area, etc. Umbrella check valve is widely applied in fuel tank, health-care field, emergency mask, medical used fluid control devices, home appliances etc.
Small Umbrella Valve Design Guide
Small Umbrella Valves have three key designs & dimensions and two key diaphragmatic surface demands:
Mushroom Shaped Diameter: bigger than one-way valve holes
Hook Height: same to plastic & metal panel's height
Stem Diameter: same or maller than assembly holes
Outside Diaphragmatic Surface: EDM process or texture surface for dust proof
Inside Diaphragmatic Ring Edge Surface: Polish or high-polishing for sealing function
Small Umbrella Valve's Materials Choice, Hardness Limits and Packaging Demands
For Small Umbrella Valves, we should choose lower compression set value and high elastomer silicone material (high tensile strength).
Silicone Umbrella Valve is best made from 100% high elasticity silicone material.
Notes: The mechanical and physical properties of fluoro silicone rubber are very similar to silicone, the difference is that fluoro silicone is oil-resistant.
Fluorosilicone rubber & FVMQ is noted for its resistance to fluro organic solvents and petroleum based fluid.
Most of automotive & machine's mushroom valves is made from fluorosilicone materials.
Umbrella Check Valves Hardness is generally less than 55 Shore A which mainly depends on umbrella hook designs
Small Mushroom Valve Packaging: PE Bag with air inside in aim to prevent deformation & out of shape.
Small Umbrella Valve Installation
Mini umbrella valve assembly ways can be divided into 3 types:
Pull-in type with long tail: This is the most common and well suited for hand assembly. To install one places the long tail through a central bore in the seat, pull it and the valve pops in place.
Push-in type: This type is preferred when the placing of a long tail in the central bore is more difficult. For example deep down in the bottom of a cylinder. Or when the upstream side of the valve is not accessible. For example when placing the valve in the wall of a tank where the inside of the tank is inaccessible. This type can also be used in automatic assembly.
Belleville type: The shape of the membrane looks like a Belleville spring washer held by an elastomeric hinge in the centre. The seat of this type of valve is much easier to manufacture because it has only one flow orifice.
Small Umbrella Valve Application
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, inlet silicone umbrella valve in manual resuscitator, and numerous other fluid control functions in medical devices, home appliances, cars and toys.
Medical field: Manual Resuscitator/ Respirator, Anesthesia Apparatus, Surgical Equipment, etc.
Automotive field: Oil Pump, engines