EP1235041A2 - Sanitary low pressure fitting - Google Patents

Abstract

Sanitary low-pressure tap fitting (1) comprises a pipeline (2) feeding water from the tap fitting to a water heater. At least one device (3) is arranged in or on the tap fitting and/or the pipeline to the water heater for at least partial equalization of a difference in pressure compared with a nominal operating pressure occurring in the tap fitting and/or the pipeline. An Independent claim is also included for a process for operating the above tap fitting comprising feeding air and/or water into the tap fitting and/or the pipeline in the event of a negative pressure difference and/or removing water from the tap fitting and/or the pipeline in the event of a positive difference in pressure. Preferred Features: The device is arranged in/on the pipeline near the tap fitting.

Description

The invention relates to a sanitary low pressure fitting with a feed line to one Water heater, through which the water heater from the tap water is feedable.

Such low pressure fittings are used where e.g. in one Residential house is not provided for a central hot water preparation, but that warm water is heated decentrally near the water supply point must become. There are separate for decentralized hot water preparation Water heaters provided, for example, as a so-called Undersink unit can be operated in conjunction with a low pressure fitting.

A typical low-pressure sanitary fitting includes the body of the fitting a connection line with which the low pressure fitting to the cold water connection the domestic water supply can be connected. Now with the low pressure valve the cold water withdrawal is set, the water flow takes place directly from the Cold water connection pipe through the volume-regulating valve body to to the tap spout.

In the event that hot water is to be withdrawn, this will be done by the Cold water flowing into the connection line within the low pressure valve a quantity regulation redirected and via a supply line from the valve Water heater supplied so that through the incoming water in the Water heater stored hot water via another return line to Outlet of the valve is directed. That in the water heater via the supply line introduced cold water, which has displaced the stored hot water with a longer stay within the storage container of the Water heater mostly electrically heated and for a later Hot water withdrawal stocked.

Low pressure fittings are designed in accordance with their name in such a way that they only up to a certain maximum operating pressure, the target operating pressure may be operated. This target operating pressure is typically at normal atmospheric pressure, i.e. at just over 1 bar. This maximum Operating pressure results, among other things, from the fact that the water heater, the comprise a hot water storage tank open to the atmosphere.

The problem with sanitary low-pressure fittings is known that one very quick opening and especially when the Valve there are considerable pressure fluctuations in the supply line from the valve to Can adjust water heater. The pressure fluctuations within the In this case, the supply line can multiply the permissible nominal operating pressure exceed and thereby to a functional impairment or in extreme cases damage the water heater.

For example, positive compared to the permissible nominal operating pressure Differential pressures, i.e. Overpressures in the supply line result in that the Low pressure valve is opened very quickly, so that the full pressure of the Domestic water supply to the still in the valve and the supply to Water heater and what is in the water heater Water volume causes what causes an overpressure in the entire system.

Negative differential pressures, i.e. Oppressions, for example show that the hot water tap is very quick when taking hot water is closed so that it is due to the existing movement of the directly behind volume of water in the cartridge of the low pressure valve Can come vacuum that sucks back this amount of water. For one, can these negative pressures too far from the target operating pressure of the low pressure valve The supply line and the water heater differ and the other causes the Negative pressure the amount of water in the system to a very rapid backflow towards the cartridge in the closed room a very high pressure surge due to its mass and flow rate can generate.

To the problem of the negative pressure that occurs and the associated problems To reduce pressure surges, it is known to low pressure fittings in terms of their Amount regulation characteristic to change due to the changed Characteristic of a slow, slow closing of the cartridge enable. However, the impact of these measures is low and requires one Manufacture of special geometries for the cartridge sealing washers, which is a Modification of previous low pressure fittings required and thus complex and is expensive.

The object of the invention is to provide a low pressure sanitary fitting Generic type to improve that of the target operating pressure deviating pressures within the low pressure valve, the supply line to the Water heater and the water heater itself in a simple way and Way e.g. prevented even without design changes to the previous components can be.

This object is achieved in that in or on the low pressure valve and / or the supply line to the water heater at least one device is arranged to at least partially compensate for one in the Low pressure fitting and / or the supply line compared to a target operating pressure occurring differential pressure.

By a low pressure fitting with such a device, it is possible The pressures in the valve exceed or fall below the target operating pressure as well as in the supply line and the water heater if not even completely compensate. The device can on the one hand in the Low pressure fitting itself, which allows it to be arranged Low pressure fittings already with the corresponding in the production Device to be provided as well in or on the feed line what offers the particular advantage of retrofitting existing low pressure fittings to be supplemented by said device.

Especially when the low-pressure valve closes very quickly Negative pressures occurring behind the control cartridge can then be particularly effective be dismantled if either the device is directly in the low pressure fitting is arranged or the device is in or on the feed line near the Low pressure valve is located.

The main problem behind a control cartridge of the low pressure valve negative differential pressure occurring can be with the invention Solve the low-pressure fitting in a particularly simple manner by using Device air can be introduced into the supply line and / or the low pressure fitting. kick now when the low pressure valve closes very quickly due to the Inertia of the moving water column behind the control cartridge Vacuum on, so the device at this negative differential pressure simply air is introduced into the supply line and / or the low-pressure fitting, which Vacuum, if not complete, will at least partially compensate for itself the differential pressure is reduced to an allowed level.

In addition to the alternative, negative differential pressures occur using inflowing Balancing air is another alternative, with a negative one Differential pressure by means of the water device, in particular pressureless water, in to initiate the supply line and / or the low pressure valve.

Compared to the previously described solution by introducing air, it has Solution the advantage that the tap, the supply line and the water heater is kept free of air bubbles, resulting in particular flow noise Have it avoided when operating the low pressure valve.

In addition to the negative differential pressures, which are particularly evident in a very setting the valve to close quickly, as mentioned above, also the problem that positive differential pressures can arise, especially if the valve opens and turns very quickly for example by limescale deposits in the supply line or in Water heaters have reduced the flow cross-sections over time.

With such a positive differential pressure, either with the same device or with another device in or on the low-pressure fitting or Supply the pressurized water from the low pressure valve and / or the supply line can be derived. So again it is possible to Pressure peaks within the entire water system to an allowed level to reduce.

So it is possible with the low pressure fitting according to the invention, both positive as well as negative differential pressures related to the target operating pressure compensate for the negative and positive differential pressure each a separate device and a single device for the two Cases of the occurring differential pressures in or on the low pressure valve or the Supply line can be provided.

A particularly simple embodiment of the device with the Low pressure valve operated according to the invention may consist in that this device comprises a membrane expansion vessel. Such a thing Membrane expansion vessel essentially consists of a container which is divided into two sections by means of an elastic membrane, the one Partial area is filled with air or gas under normal or positive pressure and the other Partial area is filled with water, which with the low pressure valve or Supply line is connected. The pressure fluctuations within the Low pressure fitting, the supply line or the water heater, both can be positive as well as negative direction, with such Diaphragm expansion vessel, e.g. is connected to the supply line, very much easy to be reduced, at least to a substantial extent, since the elastic Diaphragm in the diaphragm expansion vessel yields to the pressure fluctuations and this dampens or intercepts. With positive differential pressures, both Water from the fitting or the supply line into the diaphragm expansion tank the water is pushed in as well as with negative differential pressures be sucked out of the diaphragm expansion vessel.

Another alternative, especially to avoid negative ones Differential pressures, i.e. suppressing the valve or supply line, can be included exist that the device comprises a flow tube aerator. Such one Flow tube aerator is characterized by the fact that through it considerable Air volumes can be introduced into the supply line within a short time, so that with a Such flow tube aerators possibly occurring negative pressures in the supply line or the valve can be effectively dismantled.

However, such a flow tube aerator has the disadvantage of being quite large Design, so that it is provided in a further alternative, in the device For example, to use a backflow preventer. At a Backflow preventer is a facility, e.g. in a Water pipe to protect against backflow and sucking back of water in the e.g. a tightly closing flap only in a normal desired The flow direction of the water opens and in the case of a flow against it Direction closes and thus prevents the water flow.

Such a backflow preventer can be carried out in a particularly simple manner be arranged inside the low pressure valve or on the supply line, because the Backflow preventer in a very small design are commercially available. to Attachment to the supply line, for example, is e.g. possible a T-connector to use, in which the two are aligned Connection pieces in particular directly behind the low pressure valve in the Inlet line are arranged and the third, outgoing from it not in alignment Connection piece for receiving a backflow preventer is used. The Backflow preventer is arranged in the T-piece in this construction, that the direction of flow of the backflow preventer into the supply line to Water heater points into it.

Since a backflow preventer prevents the flow of a fluid, e.g. Water or air, is only permitted in one direction, the connecting piece with the Backflow preventer with both open and closed Hot water withdrawal closed so that no water from the supply line can escape through the backflow preventer.

However, e.g. by closing the Low pressure valve a negative pressure after the valve body within the Supply line, this negative pressure causes the backflow preventer to open, whereby outside air flows through the backflow preventer into the supply line can. The negative pressure is then reduced by this inflowing outside air.

As an alternative to introducing outside air into the supply line, it is also possible to to connect a water reservoir to the backflow preventer, so that with one negative pressure occurring in the supply line through the backflow preventer water instead of sucking in air, which compensates for the negative pressure and would have the advantage that air bubbles in the water pipe system are avoided.

Basically, a backflow preventer is used both in the Low pressure valve as well as to arrange in the feed line such that this one Leakage of water from the supply line and / or the low pressure fitting prevents, however, the introduction of air and / or in the event of a negative pressure Guaranteed water in the supply line to reduce the negative pressure.

A low pressure fitting according to the invention can according to the above statements be operated in such a way that in the event of a deviation in the actual operating pressure in the Low pressure valve and / or the supply line from a permissible nominal operating pressure in the event of a negative differential pressure, air and / or water into the Low pressure valve and / or the feed line is introduced and / or that in the In the event of a positive differential pressure, the water from the low pressure fitting and / or the supply line is derived in order to increase the impermissible pressure conditions prevent or dismantle and thus a functional operation of the valve and to ensure the water heater.

An embodiment of the device, as in an inventive Low pressure valve is used is shown in the picture.

Figure 1 shows the lower end of a low pressure sanitary fitting for example, with this lower end 1 on a worktop or sink or a sink can be attached. A feed line 2 is also shown, over the cold water from the fitting 1 to the water heater, not shown is guided in the direction of arrow 7. The figure does not show the Connection line between low pressure valve 1 and the domestic water supply as well as the return line between the water heater and the Low pressure valve 1. This usually on a low pressure valve provided further lines do not contribute to the invention.

The figure shows a device 3, which is within the feed line 2 in the immediate vicinity Is arranged close behind the low pressure valve. The device shown here serves in the exemplary embodiment an at least partial compensation of one in the Armature 1 or the supply line 2 occurring vacuum and subsequent Overpressure shock waves, such as can arise when the Low pressure valve 1 is closed very quickly. Here is the device 3 from a T-piece 4 and a backflow preventer 5 arranged therein.

The T-piece 4 is arranged such that the feed line 2 passes through the two aligned fittings of the T-piece and the Backflow preventer 5 in the further, non-aligned connector, which in the present case vertically extending from the feed line 2, is arranged.

The backflow preventer 5, which is a commercially available one cylindrical check valve is in the third connection piece of the T-piece 4 used that the permissible flow direction of the Backflow preventer 5 points into the feed line 2.

Accordingly, it is ensured that both when closed and Open hot water withdrawal that is in the supply line 2 or through this water flowing through not through the backflow preventer 5 from the line can escape, but when a negative pressure occurs in the supply line 2 It is ensured that outside air through the backflow preventer 5 in the direction of the arrow 6 flows into the feed line 2 and thereby largely the negative pressure compensated.

This ensures that the water in the feed line 2 flows back does not occur and thus pressure surges within the supply line 2 of the low-pressure fitting 1 and the water heater, not shown, can be avoided.

Accordingly, safe operation can be achieved with the construction according to the invention a low pressure valve can be guaranteed without, for example, the To have to modify the low pressure valve itself. The one shown in the picture Device 3 is also for retrofitting to conventional low pressure fittings suitable.

Claims (9)

Sanitary low-pressure fitting (1) with a feed line (2) to a water heater, via which water can be fed to the water heater from the low-pressure fitting (1), characterized in that in or on the low-pressure fitting (1) and / or the feed line (2) Water heater at least one device (3) is arranged for at least partial compensation of a differential pressure occurring in the low-pressure fitting (1) and / or the feed line (2) with respect to a desired operating pressure. Low-pressure fitting according to claim 1, characterized in that the device (3) is arranged in / on the feed line (2) near the low-pressure fitting (1). Low-pressure fitting according to one of the preceding claims, characterized in that, in the case of a negative differential pressure, air can be introduced into the feed line (2) and / or the low-pressure fitting (1) by means of the device (3). Low-pressure fitting according to one of the preceding claims, characterized in that, in the event of a negative differential pressure, water, in particular pressureless water, can be introduced into the feed line (2) and / or the low-pressure fitting (1) by means of the device (3). Low-pressure fitting according to one of the preceding claims, characterized in that, when the differential pressure is positive, water under excess pressure can be discharged from the low-pressure fitting (1) and / or the feed line (2) by means of the device (3). Low-pressure fitting according to one of the preceding claims, characterized in that the device (3) comprises a membrane expansion vessel. Low-pressure fitting according to claim 3, characterized in that the device (3) comprises a flow tube aerator. Low-pressure fitting according to claim 3 or 4, characterized in that the device (3) comprises a backflow preventer (5), in particular which prevents water from escaping from the feed line (2) and / or the low-pressure fitting (1) and by means of the air and / or water can be introduced into the supply line (2) and / or the low-pressure fitting (1). Method for operating a low-pressure fitting (1) with a feed line (2) to a water heater via which water is supplied to the water heater from the low-pressure fitting (1), characterized in that if the actual operating pressure in the low-pressure fitting (1) and / or deviates the supply line (2) from a target operating pressure a) in the case of a negative differential pressure, air and / or water is introduced into the low-pressure fitting (1) and / or the feed line (2) and / or b) in the case of a positive differential pressure, water is discharged from the low-pressure fitting (1) and / or the feed line (2).

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