CA1044560A - Combined stop and control valve - Google Patents
Combined stop and control valveInfo
- Publication number
- CA1044560A CA1044560A CA251,493A CA251493A CA1044560A CA 1044560 A CA1044560 A CA 1044560A CA 251493 A CA251493 A CA 251493A CA 1044560 A CA1044560 A CA 1044560A
- Authority
- CA
- Canada
- Prior art keywords
- valve
- control valve
- piston
- valve piston
- control
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
- F01D17/00—Regulating or controlling by varying flow
- F01D17/10—Final actuators
- F01D17/12—Final actuators arranged in stator parts
- F01D17/14—Final actuators arranged in stator parts varying effective cross-sectional area of nozzles or guide conduits
- F01D17/141—Final actuators arranged in stator parts varying effective cross-sectional area of nozzles or guide conduits by means of shiftable members or valves obturating part of the flow path
- F01D17/145—Final actuators arranged in stator parts varying effective cross-sectional area of nozzles or guide conduits by means of shiftable members or valves obturating part of the flow path by means of valves, e.g. for steam turbines
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Control Of Turbines (AREA)
- Lift Valve (AREA)
Abstract
ABSTRACT
A combined stop and control valve for turbine installations and in particular a steam turbine in which the bodies of independently operable stop and control valves are arranged co-axially to another in a common housing. The control valve is located downstream from the stop valve and opens in the direction of steam flow through it, and the body of the control valve is in the form of a pressure-relieving or servo piston actuated by a spindle.
The body of the stop valve is also actuated by means of a pilot valve connected to an actuating spindle.
A combined stop and control valve for turbine installations and in particular a steam turbine in which the bodies of independently operable stop and control valves are arranged co-axially to another in a common housing. The control valve is located downstream from the stop valve and opens in the direction of steam flow through it, and the body of the control valve is in the form of a pressure-relieving or servo piston actuated by a spindle.
The body of the stop valve is also actuated by means of a pilot valve connected to an actuating spindle.
Description
The invention concerns a combined stop and control valve for turbine installations, in particular for steam turblne installationæ, the stop and control valve bodie~ of which are arranged coaxially to one another ina common hous- -ing and can be controlled independently of each other.
In present-day power plant installation~ the control valves in the pipes carrying the working medium to the turbines, particularly in the case of steam turbines, are alway~ ~upplemented by fast-acting stop valves so that at least a high-speed shutdown can be carried out in the e~ent of a control failure or in response to any other external influences. The u~ual principle of duplicated ~ ;
safety for the whole power installation is thus maintained.
For a long time, so called interceptor valves have been fitted in the reheat line of steam turbines with reheater~, as otherwise the volume of steam present in the reheater and in the connecting pipe would be sufficient following a shutdown, even though the high-pressure line was closed, to accelerate the turbine rotor to an unacceptably high over-speed which itself would endanger the whole power in~tallation.
Combined stop and control valves are known,Swiss patent No. 539 805,in which the control valve and the stop valve are contained in a common valve housing. The body of the control valve is situated upstream from the body of the stop valve and has the shape of a bell into the hollow portion of which the plate-shape stop valve travels during the opening movement. Here~ the valves are prefer~bly so connected that in their end positions the two valve bodies are in the same position relative to one anoiher.
During the course of power plant development, with large steam volumes it was reasonable to employ this form of ~alve for live steam control valves, as well as for interceptor
In present-day power plant installation~ the control valves in the pipes carrying the working medium to the turbines, particularly in the case of steam turbines, are alway~ ~upplemented by fast-acting stop valves so that at least a high-speed shutdown can be carried out in the e~ent of a control failure or in response to any other external influences. The u~ual principle of duplicated ~ ;
safety for the whole power installation is thus maintained.
For a long time, so called interceptor valves have been fitted in the reheat line of steam turbines with reheater~, as otherwise the volume of steam present in the reheater and in the connecting pipe would be sufficient following a shutdown, even though the high-pressure line was closed, to accelerate the turbine rotor to an unacceptably high over-speed which itself would endanger the whole power in~tallation.
Combined stop and control valves are known,Swiss patent No. 539 805,in which the control valve and the stop valve are contained in a common valve housing. The body of the control valve is situated upstream from the body of the stop valve and has the shape of a bell into the hollow portion of which the plate-shape stop valve travels during the opening movement. Here~ the valves are prefer~bly so connected that in their end positions the two valve bodies are in the same position relative to one anoiher.
During the course of power plant development, with large steam volumes it was reasonable to employ this form of ~alve for live steam control valves, as well as for interceptor
- 2 -~k ' ~ : ................... ., :.... - ~
. .. . . -1~4~6V
valves. The bell-shaped control valve then serve6 to modify the performance of the steam turbine in response to load variations.
It has been found, however, that this form of valve ha~ a tendency to vibrate when the control valve i8 in the throttled position. Consequently, damage due to wear and - cyclic stresses can occur with prolonged part-load operation.
The general ob~ect of the invention is to avoid the disadvantage stated above. This objective i5 achieved in that the control valve i~ located down5tream from the stop valve and opens in the direction of the steam flow, and the control valve body is in the form of a relieving or servo pi~ton.
The advantage of the invention is to be seen in '~'i the fact that with the stop valve ahead of the control valve, viewed in the flow direction, vibratlon-free location of the valve body i~ achleved by the full pre6sure difference be-tween live steam and atmosphere in the open position. Fur-thermore, in contrast to the combined valve mentioned above, the stop valve body i8 no longer subJected to the throttled ma88 flow ~et ~rom the control valve during operation, thus eliminating a further source of vibration. In the case of the proposed control valve, the advantage is to be seen in the fact that the throttled flow moves away from the center ;
and thus an energy concentration in the center in the direc-tion of the valve movement is completely avoided, greatly reducing the tendency to vibrate.
In a preferred alternative form of the invention, in order to relieve the pressure on the valve components, the stop valve is provided with a pilot valve located at one end of a valve spindle. Sleeve inserts rigidly ~ixed to the body of the stop valve can be provided with valve ,- :..... .. . ~ , :, .. , - : . . . , , ~
- ~ .: . ~ .
. ~ :
.. . .. . .
~ 10~5ti0 seats via which the valve lift is carried out.
It is of particular advantage if the stop valve body and the cover accommodating it in the open positlon are provided with an annular flat seat which ensure6 a well-fitting position of both components when the valve is open.
According to a pre~erred alternative embodiment, the working medium can be admitted to both sides of the control valve. In this case it is recommended that working medium should be drawn from the upstream side of the control valve through drilled holes in the valve body.
; Further, it is of benefit to make the piston surfaces of the control valve of such dimensions that the forces applied by the working medium exert a clQsing effect on the control valve. With an arrangement of this kind a pilot valve is not necessary, and therefore, owing -~-to the absence of freely moving parts in the steam space, the valve design ls very simple and hence esAentially less su6ceptible to defects.
In an alternative form of the invention the control valve body is provided with a control sy~tem acting sequen-tially to the pressure of the working medium. In this case it is recommended that ir the piston spaces are li~X~d to working-medium system when the control valve opens, the pressure level of thiæ system should be lower than the pressure level of the working medium to be controlled by the control valve.
In addition to the known advantage of the prin-ciple of anticipatory control, namely of obtaining suffi-ciently large actuating forces with adequately low inertia, the particular advantage of this configuration is to be seen in the fact that the control valve body in the form of : . ... ,: .. ~
45f~0 a servo piæton is controlled by the working medium it~elf.
Because high hydraulic pressures are not needed, savings are achieved in pump capacity, and in addition the whole extent of the system is reduced.
Examples of the invention are shown in simplified form in the drawings, in whi~h: -Fig. 1 ~hows a section through a combined stop and control valve, and Fig. 2 1~ a detall ~ectlon through the ~ame valve being actuated by a follow-up plston.
Component~ not essential to the invention, such as splndle bearings, ~eals, fastenings, means of spindle ad~ustment, etc., are omitted for the sake of clarity.
As shown in Fig. 1, a common housing 1 contains the ~top valve 2 and the control valve 3. On the inlet side of the combined valve a cylindrical steam strainer 4 i6 attached on the one hand to the cover 5 of the stop valve 2, and on the other to the valve ~eat 6. In the open posltion lllu~trated, the ~top valve body 7 and the valve seat 6 form a hydro-dynamlcally favourable, annular lnlet channel to the control valve 3.
The ætop valve 2 is actuated by way of a spindle 8, the valve-end of whlch is in the form of a double-seated pilot valve 9. Fixed to the valve body 7 are two sleeve inserts lO and 11, each of which has a valve seat 12 or 13, respec-tively, and radial holes 14 and 15.
With the valve in the open position illustrated, the valve body 7 and the valve cover 5 form a seal with respect to the steam space by means of annular flat seat 16 and the seat 12 of the pilot valve 9. The seating 16 also ensures that the valve body 7 i~ firmly located against - 5 ~
- . ~ - . . :
-.; : , the cover 5. 1~4S~
To explain the principle of operation, a valve through which working medium is flowing can be considered first. The ~ull steam pressure obtaining in the steam space acts on the body o~ the stop valve 7. The closing procedure i8 initiated by pushing in the spindle 8. The pllot valve 9 separates from seat 12 and engages seat 13.
Flowing through hole 17 in cover 5, hole 18 in the valve body 7, hole 1~ in the sleeve insert 10 and also through the open valve ~eatlng 12, working medlum passes along the annular gap 19 between spindle 8 and sleeve insert 11 and through hole 15 in sleeve insert 11 into the equalising ~ .
space 20. The pressure in space 20 on valve body 7 is thus increased; as the spindle 8 moves in further, the valve body 7 is drawn along by way of the pilot valve 9 resting on valve seat 13.
If the stop valve 2 is to be opened from the closed posltlon, this procedure ls initiated by raising the spindle 8. The seat 13 is freed, and worklng medlum flow~ via holes 18, 14, the open seat 13 and hole 21 from the flow approach ~lde into the space form by the closed stop an~ control valves and by valve seat 6. Pressure in this space 7 is thus increased and the body follows further raising o~ spindle 8 by way of the valve seat 12 engaging pilot valve 9.
The control valve body 22 of the control valve 3 is in the form of a piston, and is rigidly joined to the actuating spindle 23. The construction requires no pilot valve and thus, owing to the absence of freely moving parts in the steam space, is very simple and not susceptible to defects. Because in operati~n the throttled working medium flows away from the center, an energy concentration at the center of the piston in the direction OI the valve travel ~5~445~0 is avoided, greatly lessening the inducement of the control valve 3 to vibrate.
The spindle 23 slides in a spindle guide 24, and the valve body-piston 22 which as illustrated has a longitudinally stepped profile slides in a piston correspondingly stepped guide 25 which forms an operating cylinder for the valve body-piston 22, the outer contour of which forms an annular diffusor 26 together with the valve seat 6. The spindle guide 24 and the piston guide 25 are fixed in the housing 1 by way of cover 27. The piston gpaces 28 and 28a are joined to the flow approach side of the control valve 3 via holes 29 and the annular gap 30. The piston surfaces of the valve body 22 are so dimensioned that the sum of the steam forces acting on the piston act to close the valve.
Since the valve can be kept closed only with presaure in the piston spaces 28 and 28a, the piston is sealed with piston rings (not shown). Leakage is kept small in this way' any leakage is led away to a space having a lower pressure via the annular gap 30 in the piston guide 25 and through hole 31 in the housing 1.
The opening and closing operations of the control valve
. .. . . -1~4~6V
valves. The bell-shaped control valve then serve6 to modify the performance of the steam turbine in response to load variations.
It has been found, however, that this form of valve ha~ a tendency to vibrate when the control valve i8 in the throttled position. Consequently, damage due to wear and - cyclic stresses can occur with prolonged part-load operation.
The general ob~ect of the invention is to avoid the disadvantage stated above. This objective i5 achieved in that the control valve i~ located down5tream from the stop valve and opens in the direction of the steam flow, and the control valve body is in the form of a relieving or servo pi~ton.
The advantage of the invention is to be seen in '~'i the fact that with the stop valve ahead of the control valve, viewed in the flow direction, vibratlon-free location of the valve body i~ achleved by the full pre6sure difference be-tween live steam and atmosphere in the open position. Fur-thermore, in contrast to the combined valve mentioned above, the stop valve body i8 no longer subJected to the throttled ma88 flow ~et ~rom the control valve during operation, thus eliminating a further source of vibration. In the case of the proposed control valve, the advantage is to be seen in the fact that the throttled flow moves away from the center ;
and thus an energy concentration in the center in the direc-tion of the valve movement is completely avoided, greatly reducing the tendency to vibrate.
In a preferred alternative form of the invention, in order to relieve the pressure on the valve components, the stop valve is provided with a pilot valve located at one end of a valve spindle. Sleeve inserts rigidly ~ixed to the body of the stop valve can be provided with valve ,- :..... .. . ~ , :, .. , - : . . . , , ~
- ~ .: . ~ .
. ~ :
.. . .. . .
~ 10~5ti0 seats via which the valve lift is carried out.
It is of particular advantage if the stop valve body and the cover accommodating it in the open positlon are provided with an annular flat seat which ensure6 a well-fitting position of both components when the valve is open.
According to a pre~erred alternative embodiment, the working medium can be admitted to both sides of the control valve. In this case it is recommended that working medium should be drawn from the upstream side of the control valve through drilled holes in the valve body.
; Further, it is of benefit to make the piston surfaces of the control valve of such dimensions that the forces applied by the working medium exert a clQsing effect on the control valve. With an arrangement of this kind a pilot valve is not necessary, and therefore, owing -~-to the absence of freely moving parts in the steam space, the valve design ls very simple and hence esAentially less su6ceptible to defects.
In an alternative form of the invention the control valve body is provided with a control sy~tem acting sequen-tially to the pressure of the working medium. In this case it is recommended that ir the piston spaces are li~X~d to working-medium system when the control valve opens, the pressure level of thiæ system should be lower than the pressure level of the working medium to be controlled by the control valve.
In addition to the known advantage of the prin-ciple of anticipatory control, namely of obtaining suffi-ciently large actuating forces with adequately low inertia, the particular advantage of this configuration is to be seen in the fact that the control valve body in the form of : . ... ,: .. ~
45f~0 a servo piæton is controlled by the working medium it~elf.
Because high hydraulic pressures are not needed, savings are achieved in pump capacity, and in addition the whole extent of the system is reduced.
Examples of the invention are shown in simplified form in the drawings, in whi~h: -Fig. 1 ~hows a section through a combined stop and control valve, and Fig. 2 1~ a detall ~ectlon through the ~ame valve being actuated by a follow-up plston.
Component~ not essential to the invention, such as splndle bearings, ~eals, fastenings, means of spindle ad~ustment, etc., are omitted for the sake of clarity.
As shown in Fig. 1, a common housing 1 contains the ~top valve 2 and the control valve 3. On the inlet side of the combined valve a cylindrical steam strainer 4 i6 attached on the one hand to the cover 5 of the stop valve 2, and on the other to the valve ~eat 6. In the open posltion lllu~trated, the ~top valve body 7 and the valve seat 6 form a hydro-dynamlcally favourable, annular lnlet channel to the control valve 3.
The ætop valve 2 is actuated by way of a spindle 8, the valve-end of whlch is in the form of a double-seated pilot valve 9. Fixed to the valve body 7 are two sleeve inserts lO and 11, each of which has a valve seat 12 or 13, respec-tively, and radial holes 14 and 15.
With the valve in the open position illustrated, the valve body 7 and the valve cover 5 form a seal with respect to the steam space by means of annular flat seat 16 and the seat 12 of the pilot valve 9. The seating 16 also ensures that the valve body 7 i~ firmly located against - 5 ~
- . ~ - . . :
-.; : , the cover 5. 1~4S~
To explain the principle of operation, a valve through which working medium is flowing can be considered first. The ~ull steam pressure obtaining in the steam space acts on the body o~ the stop valve 7. The closing procedure i8 initiated by pushing in the spindle 8. The pllot valve 9 separates from seat 12 and engages seat 13.
Flowing through hole 17 in cover 5, hole 18 in the valve body 7, hole 1~ in the sleeve insert 10 and also through the open valve ~eatlng 12, working medlum passes along the annular gap 19 between spindle 8 and sleeve insert 11 and through hole 15 in sleeve insert 11 into the equalising ~ .
space 20. The pressure in space 20 on valve body 7 is thus increased; as the spindle 8 moves in further, the valve body 7 is drawn along by way of the pilot valve 9 resting on valve seat 13.
If the stop valve 2 is to be opened from the closed posltlon, this procedure ls initiated by raising the spindle 8. The seat 13 is freed, and worklng medlum flow~ via holes 18, 14, the open seat 13 and hole 21 from the flow approach ~lde into the space form by the closed stop an~ control valves and by valve seat 6. Pressure in this space 7 is thus increased and the body follows further raising o~ spindle 8 by way of the valve seat 12 engaging pilot valve 9.
The control valve body 22 of the control valve 3 is in the form of a piston, and is rigidly joined to the actuating spindle 23. The construction requires no pilot valve and thus, owing to the absence of freely moving parts in the steam space, is very simple and not susceptible to defects. Because in operati~n the throttled working medium flows away from the center, an energy concentration at the center of the piston in the direction OI the valve travel ~5~445~0 is avoided, greatly lessening the inducement of the control valve 3 to vibrate.
The spindle 23 slides in a spindle guide 24, and the valve body-piston 22 which as illustrated has a longitudinally stepped profile slides in a piston correspondingly stepped guide 25 which forms an operating cylinder for the valve body-piston 22, the outer contour of which forms an annular diffusor 26 together with the valve seat 6. The spindle guide 24 and the piston guide 25 are fixed in the housing 1 by way of cover 27. The piston gpaces 28 and 28a are joined to the flow approach side of the control valve 3 via holes 29 and the annular gap 30. The piston surfaces of the valve body 22 are so dimensioned that the sum of the steam forces acting on the piston act to close the valve.
Since the valve can be kept closed only with presaure in the piston spaces 28 and 28a, the piston is sealed with piston rings (not shown). Leakage is kept small in this way' any leakage is led away to a space having a lower pressure via the annular gap 30 in the piston guide 25 and through hole 31 in the housing 1.
The opening and closing operations of the control valve
3 require no further explanation, as the body of the control valve 22 is raised or lowered, respectively, via the actuating spindle 23.
Fig. 2 shows on a rather larger scale the control valve 3' which, unlike the version of Fig. 1, is provided with steam-operated pilot control. Wherever components of the arrangement in Figure 2 coincide with those in Fig. 1, they are identified by the same reference symbols. If only the function is the same, but the manner of execution is different, however, the same reference symbols are distinguished by a prime.
The valve body 22' is a servo piston with steam pres-sure follow-up control, and is therefore no longer rigidly connected to the actuating spindle 23~. Piston 22'
Fig. 2 shows on a rather larger scale the control valve 3' which, unlike the version of Fig. 1, is provided with steam-operated pilot control. Wherever components of the arrangement in Figure 2 coincide with those in Fig. 1, they are identified by the same reference symbols. If only the function is the same, but the manner of execution is different, however, the same reference symbols are distinguished by a prime.
The valve body 22' is a servo piston with steam pres-sure follow-up control, and is therefore no longer rigidly connected to the actuating spindle 23~. Piston 22'
4 ' ~ 4S6~
and spindle 23 ' again slide in piston guide 25 and spindle guide 24', respectively. Inside the piston is a sleeve insert 32 which, for reasons of clarity, i5 shown as being in one piece. This sleeve insert 32, which for purpo~es of assembly can of course be in several parts, is rigidly attached to the piston and incorporates holes 33 ~oining to annular space 34. The latter is connected to the flow approach side of the valve body 22' via the hole 35. The space 36 inside the piston i6 connected to a steam system ~not shown) of lower pressure (in the case of reheat turbines, for example, the outlet of the high-pressure turbine if a hlgh-pressure control valve is concerned) via the channel 37 and recess 39, both of which are machined on the valve body, and via space 46, hole 30' and the recess 40 in the piston gulde 25, and also vla the hole 31 in housing 1. The sleeveinsert 32 has a recess which is provlded with two control edges 41, 42. A thickened portion of the actuating spindle 23 ' engages in this rece6s, the thickened portions having control edges corresponding to the control edges 41 and 42.
The actuatlng spindle 23' is provided with a cavity 45 which is permanently in communication with the piston space 20 and, via space 46 which i8 in the form of a slot, with the piston space 28a. By way of the control edgeæ 41, 42, therefore, the piston spaces 28 and 28a can be connected as desired to the flow approach side of the control val~e 3' or to the steam system of lower pressure.
The follow-up control system functions in the following manner:
Witn the control valve body 22' closed, let it be 3 assumed that the actuating spindle 23 ' moves downwards from the position shown. Control edge 42 closes, control edge 41 opens the connection between the space of lower pressure 36 , 1~445~0 and the cavity 45 communicating with the piston spaces 28 and 28a. As a result, high-pressure steam escapes from the piston spaces 2~ and 28a through the channel system 28a, 46, 28, 45, s 41, 36, 37, 39, 4r(~ 30', 40, and 31. The pressure in the piston spaces 28 and 28a falls, and the steam ~orces acting ; on the control valve body 22' from its flow approach side move the body downwards in the opening directlon. In consequence, control edge 41 is again closed, the control edge 42 begins to open untll, via the channel 8y8tem 35, 34, 33, 45, 28, 46 and 28a, a pres8ure is reached in piston spaces 28, 28a which balances the opening steam forces.
; The hole 30' in the piston guide 25 is pre~erably made as a throttle; in this way a substantial pressure change can occur temporarily in space 47 when the piston moves quickly. The purpose of this measure, and also the config-uration of space 46, is to have a damping counteraction on the tendency of the follow-up piston to vibrate.
, .
_ 9 _ ,., ~ . . .
~.
and spindle 23 ' again slide in piston guide 25 and spindle guide 24', respectively. Inside the piston is a sleeve insert 32 which, for reasons of clarity, i5 shown as being in one piece. This sleeve insert 32, which for purpo~es of assembly can of course be in several parts, is rigidly attached to the piston and incorporates holes 33 ~oining to annular space 34. The latter is connected to the flow approach side of the valve body 22' via the hole 35. The space 36 inside the piston i6 connected to a steam system ~not shown) of lower pressure (in the case of reheat turbines, for example, the outlet of the high-pressure turbine if a hlgh-pressure control valve is concerned) via the channel 37 and recess 39, both of which are machined on the valve body, and via space 46, hole 30' and the recess 40 in the piston gulde 25, and also vla the hole 31 in housing 1. The sleeveinsert 32 has a recess which is provlded with two control edges 41, 42. A thickened portion of the actuating spindle 23 ' engages in this rece6s, the thickened portions having control edges corresponding to the control edges 41 and 42.
The actuatlng spindle 23' is provided with a cavity 45 which is permanently in communication with the piston space 20 and, via space 46 which i8 in the form of a slot, with the piston space 28a. By way of the control edgeæ 41, 42, therefore, the piston spaces 28 and 28a can be connected as desired to the flow approach side of the control val~e 3' or to the steam system of lower pressure.
The follow-up control system functions in the following manner:
Witn the control valve body 22' closed, let it be 3 assumed that the actuating spindle 23 ' moves downwards from the position shown. Control edge 42 closes, control edge 41 opens the connection between the space of lower pressure 36 , 1~445~0 and the cavity 45 communicating with the piston spaces 28 and 28a. As a result, high-pressure steam escapes from the piston spaces 2~ and 28a through the channel system 28a, 46, 28, 45, s 41, 36, 37, 39, 4r(~ 30', 40, and 31. The pressure in the piston spaces 28 and 28a falls, and the steam ~orces acting ; on the control valve body 22' from its flow approach side move the body downwards in the opening directlon. In consequence, control edge 41 is again closed, the control edge 42 begins to open untll, via the channel 8y8tem 35, 34, 33, 45, 28, 46 and 28a, a pres8ure is reached in piston spaces 28, 28a which balances the opening steam forces.
; The hole 30' in the piston guide 25 is pre~erably made as a throttle; in this way a substantial pressure change can occur temporarily in space 47 when the piston moves quickly. The purpose of this measure, and also the config-uration of space 46, is to have a damping counteraction on the tendency of the follow-up piston to vibrate.
, .
_ 9 _ ,., ~ . . .
~.
Claims (9)
1. In a combined stop and control valve for turbine in-stallations and in particular for a steam turbine installation wherein the movable bodies of the stop and control valves are arranged coaxially to one another in a common housing and are controllable independently of each other, the improvement wherein said control valve is located downstream from said stop valve and opens in the flow direction of the pressurized working medium, said control valve body being in the form of a piston, a spindle for actuating said valve piston, a cylinder within which said valve piston operates, one end of said valve piston being engage-able with the control valve seat, and means for admitting the working medium to the opposite end of said cylinder for applying a pressure-relieving force against the opposite end of said valve piston.
2. A combined stop and control valve as defined in claim 1, wherein the relative dimensions of the opposite end surfaces of said valve piston are such that the pressure of the working medium tends to move said valve piston in the valve-closing direction.
3. A combined stop and control valve as defined in claim 1, wherein said means for admitting the working medium to the opposite end of said cylinder is constituted by a passageway through said valve piston from one end thereof to the other.
4. A combined stop and control valve as defined in claim 1, wherein said valve piston is hollow, and said spindle is slidable within a guide member disposed within said hollow valve piston.
5. A combined stop and control valve as defined in claim 1, wherein said valve piston is hollow, said spindle is slidable within a guide member disposed within said hollow valve piston, and said hollow valve piston includes a passageway through the seat-engaging end thereof and through a gap formed between said spindle guide and the interior wall of said piston for admitting the working medium to the opposite end of said cylinder.
6. A combîned stop and control valve as defined in claim 1, wherein said spindle is connected directly to said valve piston.
7. A combined stop and control valve as defined in claim 1, wherein said spindle is coupled to said valve piston by way of a pilot valve assembly located within said valve piston and which establishes a follow-control actuated by the pressure of the working medium.
8. A combined stop and control valve as defined in claim 1, wherein said hollow valve piston and cylinder have corres-ponding step-like longitudinal profiles.
9. A combined stop and control valve as defined in claim 1, and which includes a further passageway in said valve piston connecting said passageway through said seat-engaging end of said valve piston with the exterior thereof when said control valve opens and thence via a passageway through the wall of said cylinder and the wall of said housing with the working medium but at a pressure level lower than that which is control-led by said control valve.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CH556475A CH584349A5 (en) | 1975-04-30 | 1975-04-30 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1044560A true CA1044560A (en) | 1978-12-19 |
Family
ID=4295695
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA251,493A Expired CA1044560A (en) | 1975-04-30 | 1976-04-29 | Combined stop and control valve |
Country Status (5)
| Country | Link |
|---|---|
| CA (1) | CA1044560A (en) |
| CH (1) | CH584349A5 (en) |
| DE (2) | DE2523297A1 (en) |
| FR (1) | FR2309710A1 (en) |
| IN (1) | IN145747B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10087773B2 (en) | 2013-07-25 | 2018-10-02 | Siemens Aktiengesellschaft | Valve for a turbomachine |
Families Citing this family (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CH635171A5 (en) * | 1978-06-08 | 1983-03-15 | Bbc Brown Boveri & Cie | DEVICE ON A DIFFUSER FOR SUPPRESSING RESONANCES. |
| SE510173C2 (en) * | 1995-04-26 | 1999-04-26 | Abb Stal Ab | valve device |
| US6070605A (en) * | 1999-01-25 | 2000-06-06 | General Electric Co. | Steam turbine valve disk vibration reducer |
| US6638014B2 (en) | 2001-08-17 | 2003-10-28 | Alstom (Switzerland) Ltd | Valve arrangement for a power plant |
| DE10219948A1 (en) * | 2002-05-03 | 2003-11-13 | Alstom Switzerland Ltd | steam turbine |
| GB0517702D0 (en) | 2005-09-01 | 2005-10-05 | Alstom Technology Ltd | Valve assembly and related arrangements |
| EP2410217A1 (en) * | 2010-07-20 | 2012-01-25 | Siemens Aktiengesellschaft | Valve for a steam turbine |
| EP2703697A1 (en) * | 2012-09-04 | 2014-03-05 | Siemens Aktiengesellschaft | Combined valve for a turbo machine |
| EP2703698A1 (en) * | 2012-09-04 | 2014-03-05 | Siemens Aktiengesellschaft | Combined valve for a turbo machine |
| EP2703699A1 (en) * | 2012-09-04 | 2014-03-05 | Siemens Aktiengesellschaft | Combined valve for a turbo machine |
| EP2703696A1 (en) * | 2012-09-04 | 2014-03-05 | Siemens Aktiengesellschaft | Combination valve for a turbo machine |
| CN106523716B (en) * | 2016-12-23 | 2020-04-17 | 上海电气电站设备有限公司 | Integrated steam inlet valve of steam turbine |
-
1975
- 1975-04-30 CH CH556475A patent/CH584349A5/xx not_active IP Right Cessation
- 1975-05-26 DE DE19752523297 patent/DE2523297A1/en not_active Withdrawn
- 1975-05-26 DE DE7516727U patent/DE7516727U/en not_active Expired
-
1976
- 1976-02-26 IN IN356/CAL/76A patent/IN145747B/en unknown
- 1976-04-28 FR FR7612649A patent/FR2309710A1/en active Granted
- 1976-04-29 CA CA251,493A patent/CA1044560A/en not_active Expired
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10087773B2 (en) | 2013-07-25 | 2018-10-02 | Siemens Aktiengesellschaft | Valve for a turbomachine |
Also Published As
| Publication number | Publication date |
|---|---|
| DE7516727U (en) | 1977-03-03 |
| FR2309710B3 (en) | 1979-01-19 |
| FR2309710A1 (en) | 1976-11-26 |
| DE2523297A1 (en) | 1976-11-11 |
| IN145747B (en) | 1978-12-09 |
| CH584349A5 (en) | 1977-01-31 |
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