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Spool & Sleeve Valve
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Welcome to a technologyWelcome to a technology
Indian Industry has Indian Industry has been longing forbeen longing for
-2-Inlet Pressure
Directional Control Valve - TechnologyDirectional Control Valve - Technology
5 41
2 3
14 12
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-4-
Spool TypesSpool Types
A spool has a number of major and minor diameters called lands and valleys. The lands seal with the valve bore and the valleys connect valve ports to control flow direction
a) Dynamic seal type has the seals on the spool.
b) Static seal type has the seals fixed in the valve bore.
c) Spool & Sleeve type have no sliding seals.
-5-
This 5/2 valve has a spool fitted with seals & the seals move with the spool therefore they are called dynamic. In the normal position: port 1 is joined to 2 and 4 is joined to 5 & in the operated position: port 1 is joined to 4 and 2 is joined to 3
14 12
Spool Valve (Dynamic Seals)Spool Valve (Dynamic Seals)Spool Valve (Dynamic Seals)Spool Valve (Dynamic Seals)
5 4 1 2 3
-6-
14 12
This 5/2 valve has a spool fitted with seals & the seals move with the spool therefore they are called dynamic. In the normal position: port 1 is joined to 2 and 4 is joined to 5 & in the operated position: port 1 is joined to 4 and 2 is joined to 3
Spool Valve (Dynamic Seals)Spool Valve (Dynamic Seals)Spool Valve (Dynamic Seals)Spool Valve (Dynamic Seals)
5 4 1 2 3
-7-
Spool Valve (Static Seals)Spool Valve (Static Seals)Spool Valve (Static Seals)Spool Valve (Static Seals)
24
14 12
This 5/2 valve has a plain spool sliding within static seals. The O Ring seals are held in carriers fixed in the valve bore and positioned by spacers (not shown).
The larger O Rings seal the valve bore with the carriers. The smaller O Rings seal the carriers with the spool
5 1 3
-8-
Spool Valve (Static Seals)Spool Valve (Static Seals)Spool Valve (Static Seals)Spool Valve (Static Seals)
14 12
This 5/2 valve has a plain spool sliding within static seals. The O Ring seals are held in carriers fixed in the valve bore and positioned by spacers (not shown).The larger O Rings seal the valve bore with the carriers. The smaller O Rings seal the carriers with the spool
5 1 3
4 2
-9-
No mechanical contact between thespool and the sleeve: air cushion
Only static seals on the sleeve
Spool And Sleeve TechnologySpool And Sleeve Technology
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Spool And Sleeve Technology, Spool And Sleeve Technology, NUMATICS propose a technology
spool and sleeve all stainless steel
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The Heart of Every Numatics Valve:The Heart of Every Numatics Valve:
The matched Spool & Sleeve
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Next question arises - what is Matched?
Both the spool and sleeve are - made of exactly the same material & tooled to be a mated for life set, with an extremely close fit.
And the material is 440 C Stainless Steel- an alloy of primarily tooling steel and stainless steel.- stainless for corrosion resistance-tool steel for machining and hardening
Often the spool & sleeve come from the same batch or pour.
Because the spool and sleeve are matched with the same material, tooled to precise tolerances and designed to have the same mass. The expansion and contraction coefficient are the same, so variations in normal ambient industrial temperatures
will not cause jamming.
-13-
Tolerances & Finish – why so close?
By today’s manufacturing standards, the spool & sleeve can be with in 10 one millionths of an inch of being true and perfectly round, .000010 in. =.00025mm
Better than 2 micro inch (2AA or 2RMS). AA- the arithmetic Average or RMS - Root Mean Square Average is simply the average of the peaks and valleys in the finish of the metal. This is glass smooth.
The minuscule clearance between the spool and sleeve having the smooth finish, centers the spool within the sleeve preventing metal to metal contact...providing a friction less fit (i.e. an air bearing effect with no wearing parts)
-14-
Life time more than 200 millions cycles
High reliability for the customerLess intervention for the maintenance Less breakdown, more productivity
35-65% of the Static & Dynamic Seals valves business is replacement part business: Sell two valves -- one Repair Kit… Sell three valves -- two Repair Kits…Etc.Numatics < 2% due to non-wearing parts
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Self Cleaning Valves
Both spool & sleeve are hardened through heat treating to 58 - 62 Rockwell “C”, so that the spool and sleeve will be harder than any potential contaminants (ex. - pipe scale).
There are round holes on the sleeve which act as a rudimentary filter to predetermine particulate size allowed to enter the spool area where it shall be chopped.
-16-
Self Cleaning Valves
Because Numatics spool & sleeve do not have dynamic “O” rings, have precise tolerances, an extremelysmooth finish and is very hard...........
This along with the equally sharp holes will guillotine any stray particulate. Therefore the valve is self-cleaning.
Compatible with all the industrial air treatment installation 50 microns
Lubricated or dry air
And the spool lands are made razor sharp.
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Freedom from Mechanical distortion
Floating spool & sleeve -- the spool & sleeve “float” within the valve body… ,which prevents twisting or torqueing of the sleeve and allows for equal masses.
Spool in body valves can jam due to torqueing or thermal expansion or contraction.
-18-
Balanced Design
Thus it is possible to apply pressure to any chamber or to exhaust any chamber without causing the spool to shift & without affecting the force required to move the spool in either direction.
In our lapped spool construction the spool action itself is completely balanced, that is the flow through the valve is confined to one or more chambers which are statically and dynamically balanced to the pressure, so that the pressure effects cancel out & have no effect on the movement of spool.
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because of: - balanced design- in line
tolerancing- spool & sleeve
style
We can be Multi-purpose... Balanced Design
… allowing us to pipe our 5 ported 4 way valve more than 50 different ways,
- vacuum and/or pressure- dual pressure- back flow- 2 way, 3 way, 4 way and 4way dual exhaust etc.
-20-
Ball locking device
Spool
Sleeve body
Flexibility of mounting in any position
holds valve in place - in vertical attitude & during loss of power changes a momentary signal to a constant condition. allowing your PC (programmable controller) to send an instant
signal (.000002 sec) to change a condition.
Ball locking device
-21-
ConstructionSpoppet Type --- Solenoid Air Pilot
Position 1
Flow paths when “B” pilot is pressurized or in command
Crossover
Flow paths when “A” pilot is pressurized or in command
Position 2
EXH IN EXH
CYL CYL
EXH IN EXH
CYL CYL
EXH IN EXH
CYL CYL
Air Leakage less than the most valves
-22-
ConstructionSpoppet Type --- Solenoid Air Pilot
Position 1
Flow paths when “B” pilot is pressurized or in command
Crossover
Flow paths when “A” pilot is pressurized or in command
Position 2
EXH IN EXH
CYL CYL
EXH IN EXH
CYL CYL
EXH IN EXH
CYL CYL
Air Leakage less than the most valves
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Does a Numatics Valve have open crossover?
No, all ports are blocked during valve shift…Valve start in “B” position.
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Closed crossover in mid-position, no port may pass air to another.
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Valve in “A” condition, complete shift.
-26-
Our lapped spool & sleeve requires virtually a constant force to operate it, regardless of the operating pressure.
Constant Operating Force
On manually operated valve, force required to operate the handle is constant under all pressure.
The pilot pressure required in external pilot valve is constant under all pressure conditions & thus response of the valves is always constant.
As we are able to match the force curve of the solenoid to the resistance offered by the valve thus higher would be our ultimate reliable operating speed capacity of the valve thus improves the life of our solenoids.
The response time i.e. the time required to energize the solenoid until the valve is fully open, is almost exactly constant & repetitive from operation to operation regardless of the line pressure.
-27-
Other Features of our Spool & Sleeve valvesOther Features of our Spool & Sleeve valves
Resistance to poor / inadequate lubrication. Resistance to sticking. No need to replace spool & sleeve. Cleaning is normally the
only maintenance required. Our design of lapped spool floating sleeve is of a shape which
lends itself well to a small design. Our valving action is more compact for a given air flow than almost any other valving action in the Market today.
Since all the movement takes place within the solenoids, the spool & the sleeve, it is possible to use light weight Aluminium castings for the valve housing.
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SXY – Spool in stainless Steel Spool without « sharky » design for dust braking Less resistant to dust Filtration at 5µm ! Spool & Sleeve Association at 3 µm Less robust, more plastic parts Not suitable for severe use condition (steel
plant, sugar plant) Less options and accessories (limited sandwich accessory rang
Spool And Sleeve Technology CompetitionSpool And Sleeve Technology Competition
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NYZ – Spool in Aluminium Lower Hardness Not easy to clean Limited range with few options
Spool And Sleeve Technology CompetitionSpool And Sleeve Technology Competition
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Spool And Sleeve as Sand ChopperSpool And Sleeve as Sand Chopper
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The End