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| NORMEX Hydrodynamic Guided Closing (HGC) |
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Hydrodynamic Guided Closing ( HGC ) Check Valves |
Fine
application difference of check valves compelled Normex
to come up with a new check Valve design named as Hydrodynamic
Guided Closing (HGC). The closing mechanism in guided and backed with return spring for quick closing. This valve has inherent ability to arrest water hammer. Normex
has succeeded in keeping very low pressure losses in this valve also.
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n Low
pressure drop (Hydrodynamic)
n Perfect
sealing (Guided closing)
n Eliminates water
hammer
n Can
work vertically, horizontally or angular
n Compact
Size, Silent Operation |
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|
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Principle :
When
the pump starts, the disc moves upward and the specially designed profile of the disk and body gives passage to the liquid / air without causing change in its velocity. This gives the aero
/ hydro dynamic effect, which results in minimum pressure drop (See fig.). When the pump stops, the disc moves backward quickly (Mouse
over fig.). Because of long axial guide there is no displacement of the disc while closing. This & the concentric machining results in perfect sealing. In addition, as
the valve is closed before the back flow starts, the problem of water hammering is eliminated.
This is a short length double flanged valve with all the internals designed
Hydrodynamically, This valve, when open, the annular area between the body and
plunger available for flow, is equal to the nominal bore area, Therefore, unlike
other spring loaded valves and conventional flap check valves, these valves offer
lower head losses and maintains laminar flow, As the valve closes, due to return
spring force, valve is 'Quick Closing', The valve gets closed before the start of back
flow/ return velocity, Hence, water hammer is eliminated in most of the cases. |
| Size(A) (mm) |
D |
W |
H |
| 40 |
150 |
85 |
85 |
| 50 |
165 |
105 |
100 |
| 65 |
185 |
128 |
120 |
| 80 |
200 |
156 |
140 |
| 100 |
220 |
194 |
170 |
| 150 |
285 |
264 |
230 |
| 200 |
340 |
346 |
290 |
| 250 |
406 |
430 |
355 |
| 300 |
457 |
500 |
398 |
| 350 |
527 |
600 |
475 |
| 400 |
578 |
686 |
560 |
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Part List / Materials of
Construction |
|
Part |
Description |
Standard |
Special |
|
1 |
Body |
Cast Iron |
Cast Steel / St. Steel |
|
2 |
Closing disc |
S. G. Iron |
Cast Steel / St. Steel |
|
3 |
Guide |
Cast Iron |
Cast Steel / St. Steel |
|
4 |
Sealing ring |
Nitrile Rubber |
Neoprene, Viton, Teflon etc. |
|
5 |
Seat ring |
L. T. Bronze |
St. Steel / Teflon (PTFE) |
|
6 |
Guide brush |
L. T. Bronze |
St. Steel / Teflon (PTFE) |
Material :
Body: Cast Iron IS210, FG200 ( min)
Closinq disc: S, G, Iron GGG40
Sealing ring: Nitrile
Guide bush/Seat: L, T. Bronze, IS318 - LTB2
• Other materials on request
Pressure
rating
Sizes
|
Rating |
| 40 - 125NB |
PN 1.6 |
| 150 - 300NB |
PN 1.6 |
| 350 - 400NB |
PN 0.6 |
| For CI Construction |
Size
150 - 300 mm =
350 mm =
Body
test : 1.5 times rated Pressure
Seat
test : 1.1 times rated Pressure
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Technical Comparison
|
| |
Check valve - Hydrodynamic Guided Closing (HGC)
&
Conventionally used Flap type |
Normex HGC model H-01 |
Conventional Flap type |
Innovative design, focused to eliminate all constraints of
conventional one and
offer optimum performance |
Conventional design carries lot of constraints. |
Internals designed in such a way that laminar flow is not disturbed to a large extent. |
Turbulance is generated in fluid flow due to design limitations.
|
Very low pressure drop acros the valve which saves energy, reduces pump cycle time duration |
Comparatively high pressure losses, requires more energy increases pump cycle time duration. |
Valve closing mechanism is guided by precise guide & plunger mechanism which ensures perfect sealing. |
Hing-pin-disc closing mechanism has lot of play which results in leakages. |
Closing mechanism supported by spring force eliminates hammer to a large extent. |
Closing mechanism is by back force of fluid hence maximum effect of hammer which causes many a times damage of pump or bursting of pipes. |
Compact space saving design. Reduces face-to-face length. Light weight hence easy handling. |
Standard full length valve higher in weight. |
Vertical or horizontal installation is easily possible.
|
Installation recommended for horizontal position. |
Symmetrically shaped design hence no top or bottom side selection for installation. |
Cover side should be always on top for installation. |
Material used is of grade FG 260 having higher tensile strength (26 N/mm2)
|
Material recommended is FG 200 having lower tensile strength (20 N/mm2) |
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- The closing mechanism is guided and backed with return spring for quick closing, opening and perfect sealing,
- Due to aero/hydro dynamic effect water hammer is eliminated,
• Working principal hydrodynamic guided closing
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Very low pressure loss, |
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