Surge prevention device
A surge prevention valve may be used to prevent the formation of an initial surge of high pressure. The valve may be located, for example, between a high pressure gas cylinder and a medical pressure regulator. The valve is provided with first and second valves located within a housing and integrating a pressurization orifice. The initial opening of the valve in an axial direction enables gas to flow through the pressurization orifice at a first flow rate. The full opening of the valve in the axial direction enables the gas to flow through the second valve at a second flow rate, which is much higher than the first flow rate. The controlled pressurization of the gas through the orifice delays the time during which the gas reaches full recompression. The valve may be further provided with a vent for venting pressurized gas away from a nominally closed top surface of the lower valve element. The valve may be also provided with a valve inlet tube extending into a gas cylinder to prevent contaminants, particles and/or impurities from entering the valve.
1. A surge prevention dual-path valve comprising:
an inlet, an outlet, and a flow path from said inlet to said outlet;
a first valve comprising an upper seat in communication with an upstream portion of an orifice;
a second valve comprising a lower cup-shaped valve element having an annular recessed area for receiving a lower seat of said second valve, said lower seat being in communication with a downstream portion of said orifice and with a vent connected to said outlet; and
a threaded piston unit arranged to initially move said upper seat in an axial direction to allow gas to flow through said orifice, and to subsequently move said lower seat in said axial direction to open said flow path.
2. The valve of claim 1 , further comprising a sealing groove in communication with said vent.
3. The valve of claim 2 , wherein said sealing groove has a ring-shaped opening which is essentially coplanar with an upper surface of a sealing element of said second valve.
4. The valve of claim 3 , wherein said sealing groove is characterized by an outer sealing groove diameter which is smaller than the diameter of said sealing element.
5. A surge prevention gas system comprising:
a surge prevention valve comprising a housing having an inlet, an outlet, and a flow path from said inlet to said outlet;
a gas container in contact with said surge prevention valve; and
a valve inlet element in communication with said surge prevention valve, at least a portion of said valve inlet element extending into and being located within said gas container, said at least a portion of said valve inlet element being non-threaded, said valve inlet element further comprising threads for connecting said valve inlet element to said gas container.
6. The surge prevention gas system of claim 5 , wherein said at least a portion of said valve inlet element has a length of about 0.5 cm to about 10 cm.
7. The surge prevention gas system of claim 5 , wherein said at least a portion of said valve inlet element has a circular cross-section.
8. The surge prevention gas system of claim 5 , wherein said surge prevention valve is a dual-port valve.