This invention relates to the construction of an one-way valve with a metal body and non-metallic conical cartridge. The valve is intended for installation in pipelines or tanks in the food and chemical industries as well as in individual user installations, to control the flow of discharge or transport of a medium at normal (gravitational) pressure or at elevated pressures up to 6 bar.

Technical Problem

Valves with conical cartridges have been used in the chemical and food-processing facilities for a long time. In the chemical industry, they are used to transport or discharge gaseous and liquid media while in the food-processing facilities they transport or discharge liquid products such as water, milk, coffee, juices, oil, wine etc.

Valves of this type conventionally feature a metal body with a conical bore into which a conical cartridge with a radial aperture of the appropriate shape is seated, and which, in conjunction with the appropriately shaped channel in the body, conducts the medium flow. Fine machined contact surfaces of the body and the cartridge must obtain reliable sealing and prevent the deposition of impurities in the system, which might cause abrasion damage of the matching surfaces which leads to the abatement of necessary valve tightness. Also, sealing contact surfaces can be damaged by corrosion, so that corrosion traces and products equally compromise valve functionality.

Abrasion is usually caused by mechanical impurities in the media while corrosion damage is the result of the aggressive media containing acids, alkalis or various oxidants. Abrasion and corrosion damage of the sealing contact surfaces of the conical bore in the body and the surfaces of the conical cartridge will be more difficult to develop if their permanent firm contact is ensured, and therein is reflected the first technical problem solved with this invention.

Another technical problem solved with this invention is the ability to adjust the pressure of the sealing surfaces contact through controlled assembly tightening of the valve cartridge.

Since said damage inevitably leads to a reduction in the reliability of the valve and its durability in exploitation, simple replacement of the conical cartridge provides the third technical problem solved with this invention. State of Art

Over the years, numerous solutions have been analyzed, and even patented, with the aim of improving the design of valves with conical cartridges. Except to design solutions, special attention was directed to the choice of materials as well as to the application of modern technologies in manufacturing the key parts of the valve.

The key parts of the valve with the conical cartridge are the valve body, the conical cartridge and the locking system of the rotating assembly that guarantees reliable sealing.

An additional structural feature that can affect the function of the valve is the geometry of the channel conducting the medium through the body and the conical cartridge.

When it comes to the choice of materials, modern technologies have enabled the metal parts to be coated with teflon of different compositions and this has been applied precisely to metal seats and sealing parts, such as the conical bore of the body and the conical cartridge. This process certainly significantly increases the manufacturing cost of the valve.

One of up-to-date technologies is the, so called precision cast or micro cast that substantially lowers the manufacturing costs for the valve by reducing waste and machining time. This technology significantly reduces the risk of contamination of the valve inside caused by the need to chemically clean welded joints.

The valve that is the subject of this patent application is conceived by taking into account modern micro cast technology in manufacturing metal parts and in the teflon cartridge pressing technology. In choosing vital parts materials, special attention is paid to materials suitable for application in the food-processing and chemical industries, as well as to their mechanical stability in exploitation.

The main problem solved in previous designs was to maintain, for as long and as stable as possible, the highest degree of sealing of the conical bore/conical cartridge assembly, to ensure the purity of the valve inside even after shutting off the media flow. In addition to sealing, various solution attempts also dealt with adjusting the pressure of the contact of the cartridge on the appropriate sealing surface on the body. The prevailing solutions here include compression springs as a live load. In the patent application, the assembly which includes the rotating stem/conical cartridge/washer is solved by construction where it is important to allow any adjustments to be done on the outside of the valve body. Also, this solution enables quick and easy replacement of a possible damaged conical cartridge which facilitates and accelerates the maintenance of the valve.

The geometry of the media flow channel, which includes the channels in the body and the corresponding openings in the cartridge and stem body, primarily solves the problem of turbulent flows at higher pressures in the valve, which could cause the entry and retention of mechanical impurities on sealing surfaces.

In this patent application the geometry of the media flow channel is considered solely from the aspect of improving the closure of the valve at the inlet side of the conical cartridge, while the impact of the mechanical impurities is prevented with the possible installation of a stainless steel filter screen at the inlet side of the valve body and the precise seating of the cartridge on the conical part of the valve body.

Since this valve is designed as a one-way valve, with a curved exiting part, there are several fittings that enable a variety of ways to connect the valve to other work systems.

Summary of Invention

To overcome the above-mentioned technological and technical problems the valve has been designed with a metal body and a replaceable Teflon cartridge.

The subject of this invention is a valve consisting of a metal body with a conical central bore perpendicular to the longitudinal axis of the body and opened on both sides, to which fits rotatible teflon conical cartridge firmly pressed onto a longitudinally splined steel stem with integrated valve handle head and firmly tightened over teflon mounted on the underside of the body with steel washer and a self locking nut, both made of stainless steel.

The metal parts of the valve are made of stainless steel of the quality suitable for use in the food and chemical industries. Non-metallic parts, such as the conical cartridge and the base washer at the bottom of the valve body, are made of glass fibre reinforced teflon doped with MoS ₂ . Along the longitudinal axis of the body, from the inlet to the outlet, through the teflon cartridge and through the body of the steel stem, runs a specially shaped channel through which the medium flows.

The valve outlet can accept various grade screens and screw-on fittings and couplings.

Opening and closing the flow through the valve is achieved by rotating the valve handle fixed to the stem head. The closed-opened position at 45 ^° in both directions is limited by the supported limiters casted on the valve body and on the stem head. The teflon washer over which the rotating assembly is tightened reduces the friction on the contact surfaces between the teflon washer and the metal body, facilitating the actuation of the valve.

The valve handle, with cast plastic grip, is welded into the stem head.

The primary goal of the invention is the reliable closure of the valve with the long- lasting tight contact between the sealing surfaces of the conical bore of the steel body and the conical body of the teflon cartridge, without the use of compression springs as a live load. This will also ensure the purity of the valve inside and allows the possibility of simply flushing the valve with clean water or detergent before changing the working medium.

The secondary goal of the invention is to provide a controlled external tightening of the assembly consisting of the teflon conical cartridge and the splined steel stem into the conical bore of the steel valve body, by using teflon and steel washers and a self- locking nut.

A further and particularly important object of the invention is the possibility of a rapid change of possibly a worn-out or damaged teflon conical cartridge.

Because of the installation of high quality materials (chemically resistant stainless steel and high quality teflon parts) and because of the modern manufacturing technology (applying precise casting and teflon pressing), the reliability of the valve will be ensured, the costs of manufacture will be reduced and the life-cycle of the valve prolonged, which can also be included in the objectives of the invention. Description of Drawings

Fig.1 Assembly drawing of the valve with replaceable teflon cartridge - longitudinal cross-section, side view.

Fig.2 Drawing of parts of the splined stem and the replaceable teflon cartridge.

Fig.3 Drawing of the tightening assembly of the splined valve stem/replaceable teflon cartridge: teflon washer, stainless steel washer, stainless steel self-locking nut and parts of outlet fittings: sieve screen, threaded cap and threaded coupling. Fig.4 Drawing of the valve stem with the handle head and the conical cartridge

including display of fluid flow channels.

Detailed Description of Invention

The presented invention - a valve with a replaceable teflon cartridge - which deals with the foregoing technical and technological problems consists, as shown in the drawings in figures 1 , 2, 3 and 4, of the cast steel body (1 ) with the conical bore (2), in which the lower part is made as a round seat (3) in which a teflon washer (27) is inserted.

On the upper part of the body there are casted-on left and right side suppotred limiters (4) defining the stroke when opening and closing the valve. In the longitudinal axis of the body there is, in relation to the conical bore, a radially arranged flow channel for fluid flow (5, 6), Fig. 1 , 2, 3 and 4. On the inlet side of the body, there is an outer thread (mail thread) G1/2" (8) with a groove for the viton sealing ring (7). On the inlet side, a recess (9) is provided for the possible mounting of the inlet screen with a vulcanised viton ring (10). On the output side of the body at 90° there is a curved outlet with a G3/8" threaded hollow (1 1 ), which serves to connect a threaded cap (12) or threaded coupling (13) mounted over different grade screens (10) with vulcanized viton sealing ring. The threaded cap or threaded coupling are fixed with a help of a hexagon Allen key that fits into the hexagon recesses (14) in the openings for the fluid out-flow, see Fig.3.

The flow control system consists of longitudinally splined steel stem (22) with a handle head and a conical teflon cartridge (19). The splined stem on the inlet side has a rectangular opening (23). Corresponding rectangular forms of the inlet part of the fluid passage in the valve body are also found on both sides of the teflon cartridge. The outlet channel in the valve body initially conforms to the teflon cartridge and the steel stem with its rectangular shape (23) and then gradually turns into a round profile ending in the outlet portion of the curved end of the body.

The steel stem in its lower portion ends in a cylindrical part with a flattening (25) and a threaded end with M8 thread (26). On the handle head, below the insertion point (15), the two support limiters (18) are cast on, which defines the position„open-closed" lining up against the corresponding limiters (4) on the top of the steel body.

When assembling the valve, the splined stem (22) is pressed into the conical teflon cartridge (19) and inserted with the required orientation of the passage opening into the conical bore of the body (2) so that the radial bores in the stem and the Teflon cartridge in the ..opened" position line up with the correspondingly shaped longitudinal channel in the body axis (5, 6). Finally, in down-up order, a teflon washer (27) and a stainless steel washer (28) are placed and tightened with a self-locking nut (29). Tightening to the exactly prescribed position in relation to the steel body achieves the required contact, the adjustable sealing pressure between the walls of the conical cartridge and the conical bore in the steel body, and the necessary matching of the fluid flow channel openings in the valve.

Turning the conical cartridge assembly by turning the valve handle 90° to the left or right to the corresponding limiters („open-closed" position), with constant maintenance of the set sealing pressure is enabled by the type of the joint of the stem and the tensioning unit where the flattened portion of the lower cylindrical part of the stem (25) is inserted into correspondingly formed bores in parts of the tensioning unit: teflon washer (27) stainless steel washer (28), see Fig. 1 , 2 and 3. Teflon washer (27) allows reduced friction when rotating the valve stem and facilitates better handling.

This construction also provides a simple and quick replacement of worn-out vital parts when servicing the valve.

The valve handle (17) is made of stainless steel with cast-on plastic grip (16), whereas the metal end is inserted into the stem head and welded to prevent entering and retaining of impurities (see drawing on Fig.1 ). Reliable and long-lasting sealing with reduced turbulence of the media due to the specially designed flow channel allows secure sealing in opening and closing the valve and thus makes it impossible to retain even the smallest impurities in any part of the valve. This effect can even be improved in case of the need for the aforementioned screen on the inlet side of the body.

Before re-using the valve or changing the media discharged or passed through, it suffices to briefly run through the valve a flow of clean water or detergent, it is not necessary to disassemble the valve to empty or wash unavailable spots.

Consequently, the main goals realized by the invention include the following:

- the valve becomes a healthier and more environmentally friendly product, because of its increased resistance to acids, alkalis and other chemical agents and because of the possibility of simple rinsing and cleaning when changing the media

- the installation of high quality materials (chemically resistant stainless steel and high quality teflon parts) and modern production technology (application of precision casting and teflon pressing) ensure the reliability of the valve, reduce its

manufacturing costs, and extending its life cycle

- the valve design enables quick and easy replacement of worn-out or damaged parts during servicing eventually

- careful sizing and shaping of the channel through which the medium flows enables minimal turbulence in the flow of media, thereby maintaining purity of the inside of the valve.

Industrial Applicability

This valve is a practicable, durable, reliable and easy to maintain product for use in the food and chemical industries as well as in the installations of individual users. According to the method of processing and the type of material, it is environmentally friendlier and healthier than the existing valves of this type. List of used Reference Marks

1 - Cast steel valve body

2 - Conical bore in the body

3 - Round seat for teflon washer

- Cast limiters on the valve body

5 - Specially designed inlet channel in the valve body

6 - Outlet channel in the valve body, with circular cross-section

7 - Sealing O-ring made of viton

8 - Outer thread on the body, G1/2" ^'

9 - Round recess for the sieve

10 - Stainless steel sieve screen with viton seal

11 - Threated hollow, G3/8"

12 - Threaded cap

13 - Threaded coupling

14 - Hexagonal recess for Allen key

15 - Round cross-section bore in the stem head

16 - Stainless steel valve handle plastic coated

17 - Valve handle plastic coated welded in the stem head

18 - Casted-on limiters on the stem head

19 - Replaceable teflon cartridge

20 - Inlet radial opening with rectangular cross-section on the teflon cartridge

21 - Outlet rectangular cross-section radial opening on the teflon cartridge

22 - Stem body with longitudinally splined part

23 - Inlet radial opening with rectangular cross-section on the stem

24 - Outlet radial opening with rectangular cross-section on the stem

25 - Flattening on the end of stem

26 - M8 threaded lower end of the stem

27 - Teflon washer with one-sidedly flattened round central bore

28 - Stainless steel washer with one-sidedly flattened round central bore

29 - Self locking stainless steel nut M8 screen