DE3007288A1 - Large hot gas pipe stop valve - has sealing rings actuated by sets of bellows connected in parallel - Google Patents

Abstract

The stop valve is for large-dia. pipes handling gas at high temp. and pressure having a spherical rotary plug, against which sealing rings are thrust axially by pressure-operated bellows. The rings have two or more sets of evenly-spaced bellows round their periphery and connected in parallel. Each group of bellows has its own pressure circuit, with pressure gauge connected to a regulator, the latter varying the pressure dependent on the discrepancy between the acutal and desired values. The regulators are connected to a control unit which, after flow has taken place for a set period in one group, automatically alters the desired value of the operating pressure in the other group.

Description

- 4 - KXR / Gi / Sc

PA 3109

HERMANN RAPPOLD & CO. GMBH Zollhausstrasse 121
5160 DUren

"Shut-off valve for pipelines of large nominal sizes"

The invention relates to a shut-off valve for pipelines large nominal diameters through which gases flow under high pressure and temperature, with a rotatable spherical Closure element and two axially displaceable sealing rings, which are actuated by actuating bellows that can be acted upon by pressure medium can be pressed against the closure member and can be moved away from it.

Such valves are used, among other things, in nuclear reactor plants for use where very high demands are placed on operational safety of the valves. This applies in particular to the functional reliability of the contact pressure and solvents for the sealing rings. This means must always be fully functional so that the shut-off valve at all times can be switched and then in the selected switch position the required tightness of the Valve seats guaranteed. In addition, they must have the

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necessary contact pressure regardless of the fluctuations in the operating pressure and temperature in the Maintain the gas line as constant as possible so the 1line-shaped sealing impressions of the with cone-ball sealing surfaces provided valve seats do not experience any overloads that could damage the sealing surfaces could lead.

In a shut-off valve known from DE-OS 26 33 809 of the type mentioned above is a ring-shaped pressing and releasing agent for the sealing rings Actuating bellows provided by two coaxial with each other arranged compensators is formed. The sealing ring is attached to the end of the annular actuating bellows and is acted on by him on one side.

The fact that each sealing ring is only actuated by a single bellows is the case with this known shut-off valve disadvantageous that any disturbance in the pressure medium circuit the operating bellows the functionality of this Bellows impaired or even destroyed. In addition, it is practical because of the design chosen there impossible, rapid build-up and precise control of the actuation pressure over the entire circumference of the sealing ring to achieve.

The invention is based on the object of avoiding these disadvantages and a shut-off valve of the type mentioned at the beginning Art to create, whose contact pressure and solvent for the sealing rings achieve and keep constant one exactly enable defined actuation pressure, and also in the event of individual malfunctions in their pressure medium circuit remain functional.

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This object is achieved in that the Sealing rings with at least two groups of on the circumference of the sealing ring evenly distributed and arranged in parallel actuating bellows are provided, and that each Bellows group has its own pressure medium circuit with one of the Actual value of the actuation pressure indicating pressure gauge and a pressure regulator interacting with it to regulate the Operating pressure as a function of the deviation between its actual value and a predetermined target value, wherein the pressure regulators interact with a control unit that after a certain period of time, if there is a flow in one of the bellows group, the setpoint of the actuating pressure changes automatically in the other bellows group.

Normally, the pressure regulators ensure that the associated bellows are subjected to a precisely defined actuation pressure which ensures the necessary tightness of the valves while avoiding overloading of the sealing surfaces. in the In the event of a malfunction in the pressure medium circuit of a bellows group, E.g. if one of the bellows in this group is damaged, a constant loss of pressure occurs in the disturbed circuit, which the Control unit registered via the pressure regulator of this group that is in operative connection with it. The control unit then ensures automatically ensures that the setpoint for the pressure regulator of the trouble-free bellows group is increased accordingly the latter reduces the pressure loss due to a higher actuation pressure compensated in the disturbed bellows group. In practice, the defective bellows group is then switched off completely and the setpoint value the actuation pressure for the intact bellows group is increased so that the latter exerts the actuation force solely on the sealing ring, which both bellows groups would normally exercise together. In this way the function of the valve is in spite of it of the fault that has occurred. Simultaneously the pressure regulator of the trouble-free bellows group ensures that

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their bellows continue to have a precisely defined actuation pressure applied, the required while avoiding overloading of the sealing surfaces Guaranteed tightness of the valve seats.

By arranging a large number of evenly distributed actuating bellows one can also build up and reduce the actuation pressure quickly and evenly.

According to a further proposal according to the invention, the groups of bellows have the same number of actuating bellows on. In this way, two or more identically designed systems are obtained, which is both manufacturing and is also advantageous in terms of control technology.

It is also provided according to the invention that the Actuating bellows in at least two groups of pressure bellows arranged on one end face of the sealing rings and at least two. Groups of release bellows arranged on the other end face of the sealing rings are grouped.

It is useful if the pressure bellows are welded on the one hand to a housing connection part and on the other hand are screwed to the sealing ring, while the release bellows are welded on the one hand to the sealing ring and on the other hand are screwed to ring brackets attached to the valve housing.

According to a further proposal according to the invention, the pressure bellows are loaded via a ring line which with the interior of the pressure bellows via holes in the housing connection part are connected.

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The pressure bellows can also be acted upon by a supply and discharge line that connects to the interior of the pressure bellows is connected via bores and an annular chamber in the housing connection part.

It is also useful if the release bellows are acted upon by a supply and discharge line that connects to the interior of the release bellows via pipe ducts that are elastically expandable coaxially to the sealing rings and connected to them Bores in the sealing rings are connected.

The invention is explained in more detail below using an exemplary embodiment.

It shows:

Fig. 1 a shut-off valve, the sealing rings with two Groups of compression and release bellows are actuated, shown in longitudinal section, namely:

a) upper half, in the open position, sealing surfaces pressed on,

b) left half below, in open position, sealing surfaces solved,

c) right half below, in the closed position, sealing surfaces pressed on,

FIG. 2 shows the detail II from FIG. 1, shown enlarged,

Fig. 3 shows a variant of the pressure medium supply and discharge for the pressure bellows according to detail III in Fig. 1,

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4 shows the pressure and release bellows of the shut-off valve according to Fig. 1, with their pressure medium circuits and control circles, shown schematically ti sch.

The shut-off valve shown in FIGS. 1 to 4 has a three-part valve housing with housing connection parts and 2 and a central part 3, also a rotatable spherical closure member 4 and two axially displaceable Sealing rings 5 and 6 on.

The spherical closure member 4 is rotatably mounted in the middle part 3 of the valve housing by means of pivot pin 7 and is operated hydraulically in both switching positions Locking bolt 8 held.

The sealing rings 5 and 6 are on compensators 9 with the Housing connecting parts 1 and 2 connected and guided axially by means of guide bolts 10.

The spherical closure member 4 and the sealing rings 5 and 6 are provided with sealing surfaces 11a to Hd or 12a and 12b which form the sealing seats of the shut-off valve.

For pressing the sealing rings 5 and 6 against the spherical closure member 4 for the purpose of producing the sealing seats Pressure bellows 13 and 14 are provided. For moving the sealing rings 5 and 6 away from the closure member 4 for the purpose of loosening release bellows 15 and 16 are provided for the sealing seats.

The pressure bellows 13 and 14 each form two groups of bellows 13a and 13b or 14a and 14b (see FIG. 4). The pressure bellows and 14 are on the outer end face of the sealing rings 5 or 6 evenly distributed around the circumference and arranged in a circle, with two consecutive

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press bellows of bellows groups 13a or Ha a pressure bellows, the bellows group 13b or 14b lies therebetween.

The pressure bellows 13 and 14 are multi-corrugated, multi-layered Small expansion joints with internal stroke limitation, which are welded to head plates 17 and 18 and with internal overpressure have a compressive effect as well as a tensile effect in the case of external overpressure. The head plate 17 is with the housing connection part 1 or 2 welded gas-tight. The head plate is screwed onto the sealing ring 5 or 6 (Fig. 2).

The Anpressbalggruppen 13a, 13b, 14a and 14b are about each an outer ring line 19a, 19b or 20a and 20b acted upon, with the interior of the pressure bellows 13 and 14 via radial bores 21 and axial bores 22 in one Flange 23 of the housing connection part 1 or 2 is connected (Fig. 1).

The application of the Anpressbalggruppen 13a, 13b, 14a and 14b can also take place according to FIG a radial bore 25, two annular chambers 26 and radial bores 27 and axial bores 28 in the flange 23 of the housing connection part 1 and 2 are connected.

The release bellows 15 and 16 each form two groups of bellows 15a and 15b or 16a and 16b (see FIG. 4). The release bellows 15 and are on the inside face of the sealing rings 5 or 6 evenly distributed on the circumference and arranged in a circle, with between two successive release bellows the bellows group 15a or 16a is interposed by a release bellows of the bellows group 15b or 16b.

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The release bellows 15 and 16 are also multi-corrugated, multi-layered Small expansion joints with internal stroke limitation, which are welded to head plates 29 and 30 and with internal overpressure have a pressure effect as well as a tensile effect in the case of external overpressure. The head plate 29 is with the sealing ring 5 or 6 welded gas-tight. The head plate 30 is screwed to ring brackets 31, which in turn on the Housing middle part 3 are attached.

The Lösebaiggruppen 15a, 15b, 16a and 16b are about each a line 32a, 32b or 33a and 33b acted upon, the with the interior of the release bellows 15 and 16 via an axially elastic pipe leadthrough 34 and a axial bore 35, an annular chamber 36 and bores 37 in the sealing ring 5 and 6 are connected (Fig. 1 and 2).

The Anpressbalggruppen 13a, 13b, 14a and 14b each have its own pressure medium circuit and its own Control loop on, and are including their pressure medium circuits and control loops are designed identically. This also applies to the Lösebaiggruppen 15a, 15b, 16a and 16b. In the following, therefore, only the pressure medium circuit! Aufe and Control loops for the pressure bellows group 13a and the release bellows group 15a are described in more detail (FIG. 4).

The outer ring line 19a of the pressure bellows group 13a is up on the one hand via lines 38, 39 and 40 to a pressure source (not shown) and on the other hand via lines 38, 41 and 42 connected to a return. In the lines 38 and 41 pressure control valves 43 and 44 are arranged, the cooperate with a pressure regulator 45a. This is also with a pressure gauge 46a in the line 38 and with a computer 47 serving as a control unit in operative connection

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The inlet and outlet 32a of the Lösebaiggruppe 15a is on the one hand via lines 48 and 40 to the pressure medium source (not shown) and on the other hand via line 49 in connection with the return.

This results in the Anpressbalggruppe 13a and 13a Release bracket group 15a the following pressure medium circuit:

Circuit for the pressure bellows group 13a:

Inlet via lines 40, 39, 38, outer ring line 19a and bores 21 and 22, return via bores 22 and 21, outer ring line 19a and lines 38, 41 and 42.

Circuit for the loosening baig group 15a:

Inlet via lines 40 and 48, inlet and outlet 32a, pipe leadthrough 34, bore 35, annular chamber 36 and Bore 37, return via bore 37, annular chamber 36, bore 35, pipe leadthrough 34, supply and discharge line 32a as well as line 49.

The circuits of the remaining pressure bellows groups 13b to 13d and Lösebaiggruppen 15b to 15d are formed accordingly and are therefore not described in more detail.

In lines 43 and 49 there are pressure regulating valves 50 and arranged, which cooperate with a pressure regulator 52a. The latter is also located with a pressure gauge 53a in the pipeline 32a and with the one serving as a control unit Computer 47 in operative connection.

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Except for the pressure regulators 45a to 45d and the pressure gauges 46a to 46d for the pressure bellows groups 13a, 13b, 14a and 14b as well as the pressure regulators 52a to 52d and the pressure gauges 53a to 53d for the release bracket groups 15a, 15b, 16a and 16b are on the computer 47 a pressure gauge 54 for the gas line pressure and a pressure gauge 55 for the pressure in the housing interior between the two sealing rings 5 and 6 connected. The computer 47 also has inputs for all other parameters that are decisive for the contact pressure and release pressure, such as the number of those in operation Bellows, permissible contact pressure on the sealing surface, effective pressurized area of a bellows, and so on Further. Finally, the computer 47 is also connected to the control device (not shown) for the actuating elements of the valve in connection, which forwards the control signals to the computer 47.

In the embodiment described, helium is provided as the actuating means for the pressing and releasing bellows. However, it is also possible within the scope of the invention to use nitrogen, for example, as the pressure medium circuits for the bellows are hermetically sealed against the helium cooling circuit provided for this valve.

The operation of the pressure and release bellows is described below with reference to the pressure medium circuits and the control circuits the pressure bellows groups 13a and 13b and the release bellows groups 15a and 15b described in more detail.

In the closed position of the shown in Fig.1, right side Valve are the bellows of the pressure bellows groups 13a and 13b Via lines 40, 39, 38 and outer ring lines 19a and 19b

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fully loaded, while the bellows of the release bellows groups 15a and 15b are relieved via lines 32a, 32b and 49. As a result, the opposing sealing surfaces 11a and 12a of the spherical closure member 4 and the sealing ring 5 pressed against each other. The pressure regulators 45a and 45b regulate in cooperation with the pressure gauges 46a and 46b and with the computer 47 the actuation pressure in the pressure bellows groups 13a and 13b as a function on the deviation between the setpoint given by the computer 47 and that of the pressure gauges 46a and 46b measured actual value. This ensures that the contact pressure ensures a completely gas-tight valve seat and, on the other hand, does not exceed a maximum allowable value that will damage each other pressing sealing surfaces would lead.

The actuation pressure is changed by means of the pressure regulating valves 43 and 44, with the help of which the bellows of the Anpressbai ggruppen 13a and 13b acted upon as required or be relieved.

To release the sealing surfaces 11a and 12a when switching over the valve, the pressure regulating valves 43 and 44 of the pressure bellows groups are used 13a and 13b as well as the pressure regulating valves 50 and 51 of the release bellows groups 15a and 15b are switched. Through this the release bellows 15a and 15b are now fully acted upon via lines 48 and 32a or 32b, while the pressure bellows groups 13a and 13b via the outer ring lines 19a and 19b, as well as lines 38, 41 and 42 are relieved. The pressure regulator Iventi1 43 is then closed and the pressure regulator valve 44 is fully open while the pressure regulating valves 50 and 51 receive their control pulses from controller 52a. The control of the actuation pressure for the contact and release

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bellows is not switched off. The pressure gauges 46a and 46b as well as 53a and 53b therefore each register the lowest and highest actual value of the actuation pressure in the corresponding groups of bellows and thus contribute to the fact that after the spherical closure member has been rotated 4 the required contact pressure is achieved again as quickly as possible.

The actuation pressure in the release arm groups 14a and 14b is controlled by the pressure regulators 52a and 52b in cooperation with the pressure gauges 53a and 53b and with the computer 47 regulated. The regulation takes place as a function of the deviation between a setpoint value specified by the computer 47 and that measured by the pressure gauges 53a and 53b Actual value of the actuation pressure in the release bellows groups 15a and 15b. Normally, the setpoint corresponds to a pressed Sealing surfaces the actual value of the pressure in the housing interior, which is measured by the pressure gauge 55. in the Malfunction, i.e. if the pressure inside the housing fails, then the release bellows groups 15a and 15b have to apply a higher counter pressure, which is then dependent on a correspondingly higher setpoint signal from computer 47 is regulated.

The travel time required to switch the valve of the spherical closure member 4 is controlled by a timer of the computer 47 and position feedback of the movable Valve parts monitored. After the turning process, the Computer 47 sends the necessary control pulses to the pressure control valves 43, 44, 50 and 51 to operate the pressure and release bellows as described above.

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Are one of the controllers 45a and 45b and 52a and 52b _s indicating a signal to the computer 47 from, the constant flow rate in one of the Druckregelventi1e 43 or 50 even after a certain time, which is dimensioned longer than the travel time of the ball-shaped closing member 4 , this is a sign of a leak in the associated pressure medium circuit, for example as a result of a bellows rupture. The computer 47 then automatically ensures that the defective pressure medium circuit is switched off and that at the same time the setpoint value of the actuating pressure in the trouble-free operating pressure medium circuit is doubled. In the event of a malfunction, the pressure regulators 45a or 45b or 52a or 52b, in cooperation with the computer 47, ensure that the bellows group that has remained intact is subjected to twice the actuation pressure as in the normal case, so that it now only applies the same actuation force. which is normally applied by both groups of bellows together.

This mode of action in the event of failure of one of the pressing or Lösebaiggruppen is also with the help of a hand operated Switch possible, which via the computer 47 also doubles the setpoint value of the actuating pressure in the pressure medium circuit of the intact bellows group.

The Anpress- und Lösebai ggruppen of the sealing ring 6 work identically as the Anpress- and Lösebaigruppen of the sealing ring 5 and are therefore not explained in more detail.

The described arrangement of the pressure and release bellows in several groups of bellows with their own pressure medium circuits and Control loops that interact with each other via a central control unit are coupled, not only allows one constantly

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pressure-controlled loading of the compression and release bellows, but also the automatic increase in the actuation pressure of the respectively intact bellows group in the event of a pressure failure in the other bellows group. In this way, a pressing force is exerted on the sealing rings, which if avoided from overloading the sealing surfaces the required Guaranteed tightness of the valve seats. In addition, the pressing and releasing device remains in place even in the event of a failure one or more bellows groups functional.

The degree of functional reliability (redundancy) of the system can be achieved by arranging three or more groups of bellows on each side of the sealing rings analogous to the arrangement according to the embodiment described increase.

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Claims (6)

KXR / Gi / Sc PA 31 HERMANN RAPPOLD & CO. GMBH Zollhausstraße 121 5160 Düren "Shut-off valve for pipes of large nominal sizes" claims 1./ Shut-off valve for pipes with large nominal widths, through which gases flow under high pressure and high temperature, with a rotatable spherical shutter and two axially displaceable sealing rings which can be pressed against the closure member by actuating bellows which can be acted upon by pressure medium are and are movable away from him, characterized in that the sealing rings (5, 6) with at least two groups of actuating bellows (13a, 13b and 15a, 15b or 14a, 14b and 16a, 16b) are provided, and that each group of bellows has its own pressure medium circuit! a pressure gauge (46a to 46d, 53a to 53d) indicating the actual value of the actuation pressure and one that interacts with it Pressure regulators (45a to 45d, 52a to 52d) for regulating the actuation pressure as a function of the deviation between its actual value and a predetermined setpoint value, the pressure regulator having a control unit (47) cooperate which, after a certain period of time, when there is a flow in one group of bellows, the setpoint of the actuating pressure in the other group of bellows automatically changes. 130036/0352 2. Shut-off valve according to claim 1, characterized in that the bellows groups (13a, 13b, 14a, 14b, 15a, 15b and 16a, 16b) have the same number of operating bellows. 3. Shut-off valve according to claim 1 or 2, characterized in that that the actuating bellows are in at least two groups on one end of the sealing rings (5, 6) arranged pressing bellows (13a, 13b or 14a, 14b) and at least two groups of on the other end face of the sealing rings arranged release bellows (15a, 15b or 16a, 16b) are grouped. 4. Shut-off valve according to one or more of claims 1 to 3, characterized in that the pressure bellows (13) are welded on one side to a housing connection part (1 or 2) and on the other hand are screwed to the sealing ring (5 or 6), while the release bellows (14) on the one hand are welded to the sealing ring (5 or 6) and on the other hand with ring brackets (31) attached to the valve housing (3) are screwed. 5. Shut-off valve according to one or more of claims 1 to 4, characterized in that the pressure bellows (13) acted upon via a ring line (19a, 19b, 20a, 20b) which are connected to the interior of the pressure bellows via bores (21, 22) in the housing connection part (1 or 2) are. 6. Shut-off valve according to one or more of claims 1 to 4, characterized in that the pressure bellows (13) acted upon by an inlet and outlet line (24), which are connected to the interior of the pressure bellows via bores (25, and 28) and an annular chamber (26) in the housing connection part (1 or 2) is connected. - o - 130036/0352 " ³ " 300728a Stop valve according to one or more of the claims up to 6, characterized in that the release bellows (14) are provided with an inlet and outlet line (32a, 32b or 33a, 33b) are acted upon, which are elastic with the interior of the release bellows via coaxially to the sealing rings (5, 6) expandable RohrvorfUhrungen (34) and bores connected to them (35, 37) and annular chamber (36) in the Dichtr.ingen are connected. 130036/0352