DE2806310A1 - Drinking water pipe reverse flow protection equipment - has pressure control valve opening unloader pipe before separator unit - Google Patents

Abstract

The equipment protects drinking water pipes against the flow of waste water in the reverse direction, having a separator tube sliding against spring action underr a pre-determined water supply pressure into a discharge boss with non-return valve and thus allowing free water flow. When pressure falls it slides back into a position shutting off the flow. A pressure control valve (11) is connected via a hydraulic control pipe (13) to the drinking water supply pipe (4) on the one side, and to the consumption side (5) of the separator unit (1) on the other. When pressure difference between supply and consumption sides falls below a set minimum, this shuts off the water supply to the separator unit, and at the same time opens up an unloader pipe (15) between the shut-off point (14) and the separator unit, and connected to the portion of the supply pipe (4') between them. With increased pressure difference the water supply is freed again and the unloader pipe it shut off.

Description

DR.-ING. DIPL.-PHYS. H. STURIES O Ö Π CO 1 Π

FATE NTANWALTE 2 P U O 3 1 U

DIPL-ING. P. EICHLER

BRAHMSSTRASSE 29, 5600 WUPPERTAL 2

• 6-

Company Alfred Waletzko Apparatebau, 58 20 Gevelsberg

Device for protecting drinking water pipes against backflowing process water

(Addition to P 27 47 941.0)

The subject of the main patent application P 27 47 941.0 is a device for protecting consumer points leading drinking water pipes against backflowing service water, with one built into the drinking water supply pipe Pipe separator is present, the one in one with an inlet nozzle provided cylinder has axially displaceably guided piston separation tube, which when exceeded a certain water inlet pressure against spring action into a drain connection provided with a non-return valve retracts and thereby releases the water flow, on the other hand, when the water inlet pressure falls below the specified value in its separate from the drain connection and at the same time the water flow preventing disconnected position arrives. Furthermore, there is a hydraulic pressure control line on the one hand with the drinking water supply and on the other hand with the service water side of the pipe disconnector connected pressure control

909840/0010

valve available, which when falling below a minimum differential pressure interrupts the water supply to the pipe disconnector between the drinking and service water side and at the same time one of the drinking water supply section located between the interrupter and the pipe disconnector The branching relief line opens, but opens the water inlet again at larger differential pressures and the Relief line closes.

The above-described pressure control valve according to the main application works perfectly insofar as it interrupts the drinking water supply to the pipe disconnector and releases the discharge line when a certain pressure is exceeded on the service water side, whereas in the event of a strong pressure drop on the service water side, especially with full service water withdrawal, the water supply to the pipe disconnector again releases and closes its discharge line. On the other hand, difficulties arise with this pressure control valve when only little water is withdrawn from the service water side, that is to say only a correspondingly small pressure drop occurs here. Then the difference between the drinking water supply pressure and the service water pressure at the pressure control valve is no longer large enough to move the pressure control valve and the valve slide that is moved by it and assigned to the interruption point in the drinking water supply pipe into the open position and at the same time move the relief line to the pipe isolator. close. Rather, in such cases, the

9098ÄO / 0010

- ^y -

Pressure control valve piston then often only in an indifferent middle position.

It is therefore the object of the present additional invention, the pressure control valve according to the main application P 27 47 941 to further develop or perfect that it also with throttled water extraction, so accordingly higher domestic water pressures still switch with certainty, i.e. into the water inlet to the pipe disconnector releasing and at the same time the relief line closing position arrives. This task is carried out according to the Additional invention through a built-in pressure control line of the pressure control valve leading to the domestic water side Solved pilot valve, which has a control piston that can be acted upon by the domestic water pressure via the pressure control line has, which alternates the pressure control line connection of the pressure control valve with either a drinking water pressure control line or to connect a discharge pipe leading to the open air. For the present additional invention So it is essential that the relatively easy to move pilot piston, which is constantly under the effect of the pressure prevailing on the service water side of the pipe disconnector and therefore also on the low pressure Is able to address differential pressures, for the respective reversal of the pressure control valve, significantly greater switching

0/0010

forces are available, hence its switching takes place correspondingly more securely, as will be described in more detail below.

The pilot valve advantageously has a substantially cylindrical valve housing with one therein centrally running, multiple offset axial bore for receiving the pilot piston, whereby in the opposite end walls of the valve housing the pressure control lines leading to the service and drinking water side open out, however, the line connection leading to the pressure control valve and the relief line connection lie on opposite circumferential points of the valve housing that are axially offset from one another. Included is the pressure control line connection leading to the domestic water side and the control piston part facing it containing valve housing part expediently from the other valve housing part containing the other line connections through several, up to the continuous axial bore ■ reaching radial bores or the like. Separation shafts liquid-wise separated, so that a perfect separation between the fresh water pipe parts on the one hand and the parts that carry domestic water on the other is guaranteed.

The pilot piston is at its pressure control valve and pressure control valve which are axially offset from one another Axial bore section containing relief connections

9098ÄO / OÖ10

. / Ιθ ·

protruding end with a seal running all around provided and to move on the face against a valve body which interacts with a valve shoulder of the axial bore Valve surface the aforementioned axial bore section from the line connection leading to the drinking water inlet side either separates or connects with it, namely after a corresponding axial displacement by the pilot piston.

Further features according to the present additional invention and their advantageous mode of operation are described on the basis of several exemplary embodiments shown in the drawing. Show in it

Fig. 1 in a schematic representation of a possible use of the device consisting of a pipe disconnector, pressure control valve and pilot valve,

2 shows a vertical section through the pressure control valve provided with an attached pilot valve in a correspondingly enlarged representation,

3 and 4 further embodiments of the pilot valve.

The drinking water protection device shown schematically in Fig. 1 is provided as in the case of the main application P 27 47 941.0 with a pipe separator 1, which is in the with a shut-off valve 2 and a downstream dirt trap 3 provided drinking water supply line 4 is installed and the latter with the service water line 5 liquid-conducting to connect or disconnect from it is allowed. For this purpose, the pipe disconnector 1 is in a known manner

909840/0010

provided with a piston separation pipe 6, which is connected in a to the drinking water supply line section 4 ' Cylinder 7 is axially displaceable and counteracts when a certain water inlet pressure is exceeded Spring action moves into a discharge nozzle 9 provided with a check valve 8 and thereby the water flow to the domestic water side 5 releases, on the other hand when falling below the certain water inlet pressure in his from the drain port 9 separated and at the same time the water flow-preventing separation position arrives, accordingly the position shown in dashed lines in FIG.

In order to ensure that the pipe disconnector 1 when too high a pressure occurs in the domestic water circuit 5 in In each case it comes into its illustrated disconnected position, a pressure control valve is already included in the main patent application 11 is provided, which via a pressure control line 12 on the one hand with the drinking water supply line 4 and via a other pressure control line 13 is connected to the domestic water side 5 of the pipe disconnector 1. This pressure control valve 11 is designed in such a way that if the pressure drops below a certain minimum differential pressure between the drinking and domestic water side the water inlet to the pipe disconnector interrupts, e.g. via the interrupt valve 14 built into the supply line 4, and at the same time one of the between this interrupter valve 14 and the pipe disconnector

909840 / 001Ö

more convenient feed line section 4 ¹ connects the branching relief line 15 with the relief line 24 leading to the outside, on the other hand, when the aforementioned minimum differential pressure is exceeded, the water inlet at point 14 is released again and the relief line 15 closes.

The pressure control valve 11 already described in the main application is preferably of the one shown in FIG Nature. It is a double piston spool valve formed, whose oppositely acted upon, provided with differently sized pressure application areas Pistons 16, 17 axially displaceable in two cylinder housing halves 18, 19 which are hydraulically separated from one another are accommodated, the cylinder housing half containing the piston 16 with the larger pressure application area has a control line connection 13 'to which, in the case of the main application, the pressure control line 13 is connected directly connects. The other cylinder housing half 19 is via the bore 21 present in the lower piston rod 20 connected to the drinking water inlet side of the pipe disconnector 1. This bore 21 thus forms the pressure control line 12 shown in dashed lines in FIG. 1. Both pistons 16, 17 are arranged at a distance one above the other. The upper piston 16 is fixed between them connected piston rod 22, which connects the two pistons 16, 17 to one another for mutual entrainment. Between

909840 / On1Ö

the two cylinder housing halves or their end caps 18 ', 19' a valve housing tube 23 is provided in which the discharge line 15 branching off from the drinking water supply line section 4 'opens. To this end, branches are offset in height the relief line 24 leading into the open air from the valve housing tube 23. The upper piston rod 22 is in Valve housing tube 23 sealingly via a plurality of sealing rings 25 arranged at corresponding distances from one another guided and thus forms an axial slide valve for the relief lines opening into the valve housing tube 23 15 and 24. The lower piston rod 20 carries at its lower end the valve body 28, which is provided with a corresponding sealing lining 27 and which is connected to the corresponding Valve seat surface 29 of a firmly screwed to the pressure control valve 11 via the connecting piece 30 Water flow connection 31 cooperates and thus a Corresponding interrupter valve 14 in the sense of the figure. Forms.

According to the present additional invention is between the line connection 13 · of the pressure control valve 11 and the pilot valve 50 is installed in the pressure control line 13. This pilot valve has an essentially cylindrical valve housing 51 with a centrally extending, multiple stepped axial bore 52 in which the pilot piston 53 is housed displaceably. The valve housing 51 is through several radially extending

9098AÖ / ÖÖ10

Bores 54, which extend up to the axial bore 52, are divided into two housing parts 51 ', 51''separated from one another in terms of liquid lines, of which the housing half 51' is connected to the pressure control line 13 leading to the service water circuit 5 via the connection piece 55 'in the associated end face 55 is. Characterized the control piston is continuously subjected 53 on its the correspondingly larger diameter piston head 53 "transmitting side by the pressure prevailing in the hot water circuit 5 fluid pressure. In contrast, can be found in the other housing part 51 '' in the existing here bore portion 52 'opens out connection bore 13' ¹ for the line terminal 13 'of the pressure control valve 11 as well as to axially offset bore terminal 56 for leading into the open discharge line (Fig. 1). Further, here the axial bore 52 having its diameter enlarged end portion 52''on existing in the end wall 58 connection piece 59 connected to the pressure control line 60 leading to the drinking water supply line 4 (cf. FIG. 1).

At its protruding into the axial bore section 52 ' At the end of the pilot piston 53 is provided with a stop shoulder 53 ″ carrying a sealing ring 61 and guided in a sealing manner on the end face in a valve sleeve 62, which is connected via a valve shoulder 52 '' 'of the Axial bore and a sealing ring 63 on it, cooperating valve flange 62 ", the axial bore section 52 *

909840/0010

from the line connection 59 leading to the drinking water inlet side either separates, as in FIG. 2, or else after the corresponding axial displacement of the pilot piston 53 and its stop shoulder 53 '' hits the Valve sleeve 62 connects to line connection 59.

In the illustration of FIG. 2, all valve parts are in a position that corresponds to the normal operating state corresponds, so the water flow position of the device. The breaker valve body controlled by the pressure control valve 28 is in its upper open position, so that the drinking water via the supply line 4 is unimpeded can flow to the pipe separator 1, the piston separating pipe 6 of which is in the water flow position, consequently, the drinking water can flow to the domestic water circuit 5. The control piston 16 of the pressure control valve is included Completely relieved via the line connections 13 ″ and 56. By constantly acting on the end face 53 '' ' Drinking water supply pressure and the acting on the larger end face of the control piston head 53 ', But the pilot piston 53 is normally also much weaker service water pressure in its in Fig. 2 shown right stop position held. But now occurs in the dhw circuit for some reason too high a liquid pressure, so that the risk of backflow over the in-flow position Rohrtenner 1 exists, this increased domestic water pressure causes a displacement of the pilot piston 53

909840/0010

to the left, with its sealing ring 61 initially the discharge line connection 56 from the pressure control valve line connection 13 ″, then against the valve sleeve 62 drives and this from their valve seat or the. Sealing ring 63 lifts off, so that thereupon the full Drinking water supply pressure via the bore section 52 'and the line connection 13' 'the control piston 16 acted upon, whereby the pressure control valve 11 or whose valve body 28 reaches its lower closed position and thus blocks the water supply to the pipe disconnector 1, but at the same time also connects the relief line 15 with the relief line 24, so that the pipe disconnector or his piston separating tube 6 reaches its separating position shown in dashed lines in FIG. 1. As soon as then the pressure in the domestic water circuit 5 drops again, even only slightly below that on the pilot piston accordingly whose dimensioning is adjustable limit, the pilot piston 53 is then again under the predominant force of the drinking water supply pressure is transferred to its right switch position, in which it first removes the valve sleeve can come back into its illustrated closed position and then the connection bore leading to the pressure control valve 11 13 '' connects to the relief line 57 leading into the open, so that the pressure control valve 11 or its Control piston 16, 17 under the sole effect of the drinking water supply pressure acting on piston 17

909840/0010

.At-

reaches its open position in which the valve body 28 fully releases the water inlet, on the other hand the relief line 15 is blocked against the relief line 24, so that the piston separating tube 6 of the separator again can immediately reach its water flow position. As for this last-mentioned process of stopping the pressure control valve 11 the full switching pressure is available, the switching process can be started even with a small amount of water being withdrawn, i.e. when the pressure in the domestic water circuit 5 is still relatively high.

The right end face of the pilot piston 53 acted upon by the domestic water line pressure is normally larger than the opposite end face 53 "'acted upon by the drinking water line pressure, with a view to the fact that the response pressure occurring in the domestic water circuit 5 should always be kept lower than the drinking water line pressure not necessarily dependent on the above-mentioned ratio of the two pressure areas of the pilot piston. Rather, the front surface of the pilot piston acted upon by the domestic water line pressure can also be ^{chosen to be equal to or smaller than its opposite front surface 53? l1} acted upon by the drinking water supply pressure, provided that between the valve housing 51 and the pilot piston 53 the latter in the direction of the drinking water

9098ACZOOiO

Pressure line connection 59 to be pressed compensating spring is provided. For example, a such compensation spring between the stop shoulder 53 ″ of the pilot piston 53 and the housing shoulder 51 ″ opposite it are provided.

A particularly advantageous embodiment for the pilot valve 50 is shown in FIG. 3. Here is the one between that. Drinking water supply connection 59 and the axial bore section 52 'located valve body 64 is solid. He is under the action of a weak spring 65, which his conical Valve surface 64 "against the corresponding valve seat surface 66 ' the inserted valve sleeve 66 seeks to press. The pilot piston 53 is here on the one hand by the one in the pressure control line 13 prevailing domestic water line pressure and on the other hand acted upon by a return spring 67. When occurring If the pressure in the domestic water line is too high, the pilot control piston 53 will also move to the left against the action of the spring 67 shifted until first the sealing ring 61 the relief bore 56 opposite the pressure control valve line connection 13 '' shut off. The pilot piston 53 then moves at the front against the valve body 64 and lifts it off the valve seat surface 66 ' from, so that the full drinking water supply pressure via the axial bore section 52 'and the connection bore 13' 'to the Pressure control valve can affect, thus the latter blocks the water supply to the pipe disconnector 1 at the point 14 and the Relief line 15 releases so that the pipe disconnector 1 reaches its disconnected position (Fig. 1). On the other hand, it sinks

90984Ö / 0010

2606310

If the domestic water line pressure is restored, the pilot piston moves 53 to the right under the action of its spring 67, whereby the valve body 64 first moves into its closed position and then the pressure control valve line connection 13 ″ with the relief line 56 is connected, which via the correspondingly actuated pressure control valve 11 for the immediate release of the Drinking water inlet leads to the pipe disconnector 1 with simultaneous closing of the relief line 15, thus the piston separation pipe 6 of the pipe disconnector 1 can get into its water flow position.

In the embodiment of the pilot valve shown in FIG its pilot piston 68 is designed as a dumbbell-shaped double piston valve, one of which piston 69 over the supply line 13 constantly from the domestic water line pressure and its other piston 70 via the connection 59 constantly from Drinking water supply pressure is applied. Since both pistons 69, 70 in the present case have approximately the same loading cross section, there is also a compensation spring here 71 is present, which corresponds to the adjustment force exerted on the piston 69, originating from the domestic water line pressure supports. Except for the two connection bores 13 ″ for the pressure control valve and 56 for the relief line 57, a line 72 branching off from the connecting piece 59 opens into the axial bore 52 at an axially offset point a. Due to the sealing elements arranged on the piston shaft 73 of the double piston valve 68 at corresponding distances from one another

9098AO / 0010

-V- 2606310

■ SO-

rings 74,75, depending on the position of the double piston valve 68, either the relief line connection 56 or the Line connection 72 which is under the drinking water supply pressure is connected to the bore 13 ″ leading to the pressure control valve or separated from it. The sealing ring 76 still present on the piston skirt seals the one containing the spring 71 Borehole section 52 against the drinking water supply connection 72, the borehole section 52 as well as the borehole

section 52 are provided with radial bores 54 leading into the open air.

It goes without saying that in all exemplary embodiments there is the possibility of a suitable selection of the piston impingement surfaces or the acting springs, the response sensitivity of the pilot piston to a large extent to vary, so that the pilot valve the respective application requirements and operating conditions in a wide range can be customized.

90984Ö / 001Ö

Claims (8)

DR.-ING. DIPL.-PHYS. H. STURIES 7 P Π R ^ 1 Π PATENT AGENCIES <£ 3 U D J IU DIPL.-ING. P. EICHLER BRAHMSSTRASSE 29, 5600 WUPPERTAL 2 Patent claims: Device for protecting drinking water pipes leading to consumer points against backflow Service water / with a pipe separator built into the drinking water supply line, which is one in one with one Inlet nozzle provided cylinder has axially displaceably guided piston separating tube, which when exceeded a certain water inlet pressure against peder action in one with a check valve provided drainage pipe retracts and thereby releases the water flow, however, when it falls below the certain water inlet pressure in its separate from the drain connection and at the same time the water flow arresting separating position arrives, as well as still with one each via a hydraulic pressure control line on the one hand with the drinking water supply and on the other hand with the service water side of the pipe disconnector connected pressure control valve, which when falling below a minimum differential pressure between drinking and service water side interrupts the water supply to the pipe separator and at the same time one of the between The discharge line branching off the drinking water feed line section located at the interrupter and the pipe disconnector opens, but if there is a larger difference 909840/0010 press releases the water inlet again and closes the relief line, according to patent application P 27 47 941.0, characterized in that that in the pressure control line (13) of the pressure control valve (11) leading to the domestic water side a pilot valve (50) is installed, which takes one of the domestic water pressure via the pressure control line (13) has loadable control piston (53) which connects the pressure control line connection (13 ') of the pressure control valve (11) alternating with either a drinking water pressure control line (60) or one leading to the open air Allow relief line (57) to connect. 2. Device according to claim!, Characterized in that that the pilot valve has a substantially cylindrical valve housing (51) with a in it centrally running, multiple offset axial bore (52) for receiving the pilot piston (53), with the opposite end walls of the The pressure control lines (13 or 60) leading to the service or drinking water side open into the valve housing, on the other hand, the line connection (13- ') leading to the pressure control valve (11) and the relief line connection (56) opposite circumferential points of the valve housing (51) which are axially offset from one another. 9038AO / 001Ö 3. Device according to claims 1 and 2, characterized in that the valve housing part (51 ') containing the pressure control line connection (55') leading to the domestic water side and the control piston part (53 ') facing it from the other valve housing part (51') containing the other line connections ^fI ) through several radial bores (54) or the like reaching up to the continuous axial bore. Separation shafts is liquid-wise separated. 4. Device according to claims 1 to 3, characterized in that the pilot piston (53) protrudes into the axial bore portion (52- ·) containing ^{the axially offset pressure control valve and relief connections (13 11 or 56) containing the end} . a seal running all around (61) is provided and the front side is to move against a valve body (62,64), which via a valve ^{surface (62 ') interacting with a valve shoulder (52 111} ) of the axial bore' (52) line connection (59) leading to the drinking water inlet side either separates or connects to it, namely after a corresponding axial displacement by the pilot piston '(53). 909SÄ 0/0010 5. Device according to claims 1 to 4, characterized in that the valve body is designed as a valve sleeve (62) and sealingly engages the end face (53 ¹¹¹ ) of the pilot piston (53) acted upon by the drinking water supply pressure which is smaller than the end face acted upon by the domestic water line pressure (53 ¹ ) of the pilot piston (53). (Fig. 2). 6. Device according to claims 1 to 4, characterized in that the end face (53 ') of the pilot piston (53) acted upon by the domestic water line pressure is equal to or smaller than its opposite end face (53 ¹¹¹ ) acted upon by the drinking water line pressure and between the valve housing (51) and the pilot piston (53) is provided with a compensation spring which seeks to press the latter in the direction of the drinking water pressure line connection (59). 7. Device according to claims 1 to 4, 'thereby characterized in that the valve body (64) is solid and under the action of a it seeks to press against a valve seat surface (66 '), weak Spring (65) is in place, and that the pilot piston (53), which is acted upon on the one hand by the pressure in the domestic water pipe, on the other hand acted upon by a return spring (67) is. (Fig. 3). 909840/0010 -5- 2606310 8. Device according to claims 1 to 3, characterized in that the pilot piston is dumbbell-shaped, on the one hand by the domestic water and on the other hand constantly acted upon by the drinking water supply pressure double piston valve (68), whose with correspondingly arranged sealing rings (74,75) provided with piston shaft (73) the drinking water supply line and relief line connections (72 and 56) which open into the axial bore (52) at axially offset points can be alternately connected to the pressure control valve connection (13 ") located between the latter (FIG. 4).