FIELD OF INVENTION
The present invention relates to a festenable lever for a Bi-plane penstock valve
door guided by a servovan attachment mounted on a tillable bottom bracket
adaptable to maintenance for seal replacement without having to dewater the
upstream pipe of the penstock valve and surge shaft gate.
BACKGROUND OF THE INVENTION
A penstock valve is a fail safe shut-off device between a reservoir /surge shaft and
the power house. A penstock valve is installed for the following functions.
(a) as an emergency closing device to shut-off water to turbine in the event of
failure of turbine water regulating mechanism and the main inlet valve to
turbine.
(b) Emergency closure device to cut-off water In the event of bursting of
penstock either due to earthquake or due to bombardment by enemy.
(c) As an isolating device for carrying out maintence of main inlet valve in the
power house.
A penstock valve is operated by an oil operated servomotor/hydraulic cylinder.
However the closing can be an emergency situation in which case, it is closed by
weighte suspended/bolted on the lever arm connected to door

Normally, the upstream of the penstock valve is dewatered for carrying out
malntenee of the penstock butterfly valve, But, an account of the presence of heavy
silt in the Himalayan rivers, the sealing of surge shaft gates is not effective. As a
result of this, the water conductor system of the penstock butterfly valve cannot be
dewatered effectively and maintenance of penstock vaive is becoming increasingly
more difficult and time consuming (Figures 1 & 2).
This serious impediment has led to a situation whereby the requirement of changing
of upstream seal of penstock valve without having to dewater the upstream water
conductor system between the penstock valve and the surge haft Is becoming a
desirable feature.
Penstock valve of earlier days consisted of single seal on the downstream side of the
valve door, A penstock valve door s operated by an oil operated servomotor /
hydraulic cylinder. However the closing can be an emergency situation, which case
it is closed by weights suspended/ bolted on the lever arm connected to door. For
carn/ing out maintenance of such a valve i,e,, changing of the seal etc., the surge
shaft gate must be closed and the conductor system dewatered,
However, the Himalayan rivers carry a lot of silt and damage the rubber seal on the
door, thereby frequently hampering the functioning of penstock valve. A damaged
seal of a penstock butterfly valve would mean hampering or slowing down of
maintenance activities and therefore leading to generation loss by reducing loss by
reduction the availabilities of generating sets.
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To reduce such problems due to leaking penstock valves on account of erosion
damage of rubber seals on the BF Valve door, recent penstock valve am being
designed with a maintenee seal on the upstream of the main seal, The maintenance
seal is provided on the upstream of the main seal, either on the upstream side disc
or on the same disc. This maintenance seal is engaged to carry out maintenance/
replacement of the mainseal of the main seal of the valve. For this, the out pipe is
dismantled and the main sea) is rep)aced. During operation, when the valve is
closed, the main seal is engaged maintenance seal is disengaged. When the valve
is open, the door is in open condition and both the seals are disengaged.
A biplane double seal penstock valve of the prior art as shown in figure 3, The main
seal gets damaged due to wire-drawing effect during the last phase of closure
operation against full flow which is heavily silt laden. Both the rubber seals fixed on
the door of the penstock valve gets damaged due to erosion effect of silt in the
flowing water.
When the downstream sea! is damaged, the closure Is not effective and is to be
replaced; and when the maintenance seal is also damaged, the replacement of main
seal becomes a problem. Due to excessive silt the surge shaft gates do not seal
properly and thereby it becomes virtually impossible to carry out maintenance
downstream of the surge shaft gates.
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OBJECTS OF THE INVENTION
The main objective of this invention is to provide a bi-p!ane double sea! penstock
valve with an arrangement to change the seal on the upstream disc without having
to dewater that water conductor system between penstock valve to the surge shaft
gate.
Another objection of this invention is to rotate the door by 180° using the same
servomotor which is used for the norma! opening and closing of the valve without
disturbing the oil pipe line connected to the servomotor.
Still another object is to devise a new design of the lever to effect the 180° rotation
of the door by using the same servomotor,
Yet another objection of the invention is to tilt the servomotor with precision and
ease from its normal operating position to the position required for turning by 180°
using a simple device.
SUMARRY OF TH EINVENTION
The maintenance seal of a bi-plane penstock valve door needs to be replaced from
time due to damages caused by erosion. For changing this maintenance seal, the
water conductor system upstream of the valve up to surge shaft gate no longer
needs to be evacuated. The invented arrangement of valve door, lever and
servomotor bracket for rotating the valve door by 180° without dismantling the oil
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pipe line to the servomotor achieves the purpose of replacement of both seals
without any problem and without dewatering in a very short time thus short time
minimizing generation loss,
BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS
Figure 1: Water conductor scheme of a hydroelectric plant (Elevation)
Figure 2: Water conductor system of a hydroelectric power plant (plant view)
Figure 3: Penstock valve of prior art
Figure 4:Innovated arrangement of penstock valve in the closed position
Figure 5:Penstock valve in the open position with locking pin engaged
Figure 6; Penstock valve door shown locked in open position and servomotor
retracted
Figure 7: Penstock valve door shown locked in open position and servomotor being
tilted to opposite side.
Figure 8:Penstock valve door shown locked in open position and servomotor piston
rod drawing out for engaging with lever on opposite side.
Figure 9:Valve door lock removed and door turned by further turned by 90° by
servomotor for changing upstream seal.
figure 10:Comparison of lever shapes
Figure ll:Comparsion of servomotor bottom covers and bottom bracket assemblies.
Figure 12;Comparison of servomotor bottom covers,
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DETAIL DESCRIPTION OF THE PftEPEREP EMBODIMENT OF THE
INVENTION
The innovated design arrangement has a very novel feature whereby the valve door
(22) can be rotated by 180°; thereby bringing the damaged seal on the upstream
side of door(30) the downstream side. Now the sliding stainless steel seal on the
upstream is engaged (to the seal which was earlier at the downstream side and now
at the upstream side) by penstock water pressure or oil pressure form pumps. The
downstream of the engaged sea) is now dewater, valve outlet pipe (18) is removed
and the damaged rubbed seal which is now on the down stream side is replaced.
After the seal replacement the door is turned back to its normal position,
For this whole exercise to be possible, the servomotor (28) operating the valve door
(22) cannot be positioned like the prior art. the lever (25) will also have a specially
designed geometry. The servomotor (28) has to be diligently position opposite to
that prior art and at an angle so the same servomotor with removing from its
foundation and without disconnecting the oil pipelines can be used.
The servomotor (28) is connected through the piston rod to the lever (25) on one
side and is stroked to open the valve door (22) horizontal position and held in
this position by engaging the lever with the help of a locking pin (37) (Figures 4 &
5). The servomotor (28) is then disengaged from the lever (25). The servomotor
(28) is stroke close again by oil pressure through oil pipe lines (Figure 6). At this
condition the servomotor (28) is prevented from felling by the help of specially built

arm (55) projections of the bottom cover which are propped against jacks (58). The
servomotor (28) is now reposition and the process of tiiting the servomotor to other
side is carried out (Figure 7) by these novei modification of the bottom bracket of
the servomotor (Figures 11 & 12), Two special shaped projections (55,56) are
provided on the bottom bracket of servomotor. By use of hydraulic jacks (58) or
mechanical screw jacks the whole servomotor is tilted to the position in a very
precise manner.
After tilting to the new position the servomotor piston rod is drawn out using oil
pressure. The angle of the servomotor is adjusted precisely using the two jacks
(58) at the special shaped bottom bracket so that the piston rod eye end matches
with the hole in special lever (Figure 8). Once again the servomotor is engaged to
the lever (25) this time on the other side, and is stroked another 90* continuing in
the same direction of motion to close the valve (Figure 9). At this closed position,
the upstream sea! (20) is at the downstream side and the down stream seal (21) is
at upstream side. The upstream sliding stainless seal is engaged to effect
maintenance action. The special lever (25) is different from the conventional lever
of the prior art as shown in Figure 10. the special projection on the lever on the
side opposite to the conventional servomotor lug (61) is another novel feature of
this innovation. This feature makes it possible to first lock the door in open condition
and the engaged with the repositioned servomotor helps in bringing about further
90° rotation. The geometrical positioning of the holes for engaging the servomotor
in the titled condition is specially precision designed to ensure the door rotates
another 90° with the same servomotor stroke as on the other side [for the first 90e
of the door movement]. Turning the door (22) by an exact 90° is important; only
under such a condition the sealing for maintenance can be effective and changing of
the downstream side seal (21) can be done without trouble,
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KEY FEATURES
Reference Character Figure
Number
1. Intake tower 1,2
2. Reservoir lf2
3. DAM 1,2
4. Surge shaft 1,2
5. Swing shaft gate 1
6. Penstock vaive House 1,2
7. Penstock Valve 1,2
8. Head race Tunnel 1,2
9. 2 nos pressure shaft 1
10. Drop SHAFT/ Pressure shaft 1,2
11. 4 nos penstock 1
12. Power House 1,2
13. Turbine 1,2
14. Main Inlet valve 1,2
15 Surge Shaft gate Grooves 2
16. Bifurcated penstocks 2
17. Valve inlet pipe 3,4,5,6,7,8
18. Valve outlet pipe 3,4,5,6,7,8
19. Maintenance Seal operated by screws 3
20. Upstream Seal no door 3
21. Down stream seal 3
22. Bl-Plane Door 3
23. Valve Center line 3,4,5,6,7,8,9
24. Flow 3,4,5,6,7,8
25 Lever AIM 3,4,5,6,7,8,9,10
26. Closing Weight 3,4,5,6,7,8,9
28 Valve servomotor/Hydraulic cylinder 3,4,5,9
29. Maintenance Seal operated by
penstock water pressure and locked
by screws in open and closed position 4
30. Locking pin Boss on Valve Body 4,5
31. Down Stream Disc 4,5,7,8
32 Hole for locking pin 4
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33. opening 4
34 Up stream Disc 4,5,7,8
35. Valve servomotor foundation 4,5,6,7,8,9
36 Bl-Plane Door IN open position 5,6,7,8
37. Locking pin engaged 5„6,
38 Jack engaged with iug to prevent
servomotor from felling down during
disengagement of servomotor pin 5„6,7,8
39 Servomotor retracted 6
40 Eye end drawn out for engaged with
hole in lever 7

41. Servomotor being aligned to the new
position 7
42. Tilting of Servomotor 7
43. Jack drawn out to push the Sug and
tilt the servomotor 7
44. Door Rotated by 90° in the next
manuver 8
45. Servomotor Engaged to the new
position 8
46. Jacks to be removed for next
manuver 8
47. Jacks to be removed when the door
is to be rotated by further 90° 8
48. lever ARM projection of special shape 9
49. ARM of lever for normal opening
and closing 9
20A UP stream Seal of door now on down
stream side for replacement 9
21A Down stream side if door engaged
with sliding maintenance seal during
seal replacement on down stream side 9
50 BORE for door trunion 10
51 Holes for fixing closing weight 10
52 Holes for connecting servomotor for
opening/dosing operation 10
53 Hole for connecting servomotor for
hiring the door by further 90 from its
fully open position 10
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54 Hole for locking the door in open
position during Tilting of servomotor
to opposite side. 10
55 lug for jacking to align the servomotor 11
56 Rounded End 11,12
57 Vertical movement of jack 11
58 jack 11
59 swivel point 11
60 turning 11
61 fug for jacking during tilting operation 12
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WE CLAIM
1. A fastenable lever for a penstock Bi-plane valve door guide by a servovan
attachment mounted on a tiltable bottom backet adaptable to maintenance
for replacement of seals, comprising:-
- a specially configured long lever arm (25) having a bore for door
trurion (50) at head side and having a plurality of holes (57) for fixing
closing weight at the free end;
- the lever provided on the left side at least one hole (54) for locking
the door in open position during tilting of servomotor to opposite side
and at least one hole (53) for connecting servomotor for truning the
door by further 90 from its fully open position;
- the lever having at least one hole (52) at the right for connecting
servomotor for normal opening closing operation;
- one hole (52) of the right hand side of the lever arm (25) is attached
with a hydranlic cylinder (28) of the servovan for normal opening and
closing operation;
- one locking pin (37) is engaged on locking pin boss valve body (30)
which the penstock valve door is in open condition after rotating by
and released the hydranlic cylinder (28) of the servovan,
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- The hole (53,44) of the leaver arml (25) is again engaged with the
hydralic cylinder (28,45) for rotating the door by 90° in the next
manover
- The servoman attachment is mounted on a tiltable bracket having a
small round hear (55) wing on one side and a medium long size round
head (5,6) wing on the other side which allows the servovan
attachment to lilt by means of Jack (58)
- At least two jacks (5,8) are provided on both side of the bracket to
perform vertical movement.
The sevovan attachment mounted on a fixed foundation
Characterized in that the lever Arm (2,5) is connected to the servovan
attachment on the side and is stroked to open the valve door in
horizontal position and held in this position by engaging the lever with
the help o flocking pin (37) Releases the servovan attachment, and
for further rotation of door by 90° the servovan attachment is fixed on
a left side hole (53) of the lever arm and the servomotor is stroked
close again by oil pressure through oil pipe live and the servomotor
attachment is placed on the specially built two arm projection of the
bottom cover to prevent from felling and the tilting of servovan
attachment is claimed out by means of two jack placed under the
projected ARM of bracket.
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2. The festenable lever arm as claimed in claim 1 made of steel material.
3= The festenable lever arm as claimed in claim 1 wherein a counted weight
(26) Is affixed during rotation,
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4. The festenable lever arm as claimed in claim 1 wherein Bore (50) is affixed
with the center of Bhpiane valve door.
5. The festenable lever arm as claimed in claim 1 which is rolateable in
closing direction for both opening and closing condition the door.
6. The servovan attachment as claimed in claim 1 wherein the cylinder
hydraulically operated.
7. The servovan attachment as claimed in claim 1 wherein the other end of
servomotor is firmly affixed with a foundation.
8. The servovan attachment as claimed In wherein the hydraulic cylinder is
placed on an projected arm bracket to tilt the movement by means of a
couple of jack drives.

The maintenance seal of a bi-plane penstock valve door needs to be replaced from
time due to damages caused by erosion. For changing this maintenance seal, the
water conductor system upstream of the valve up to surge shaft gate no longer
needs to be evacuated. The invented arrangement of valve door, lever and
servomotor bracket for rotating the valve door by 180° without dismantling the oil pipe line to the servomotor achieves the purpose of replacement of both seals
without any problem and without dewatering in a very short time thus short time
minimizing generation loss.