Pyro valve replacement
Mechanical spring operated permanent valve
Valdis Krumins & Sam Hyde
20/02/2015
Confidential. © 2015 AMRC with Boeing.
Template - AMRC.DPGPPT Revision 1 (February 2015)
Initial Ideas
Pyro
Magnetic
Magnetic spring
Piezo
Electro Magnetic
Spring
2
Inspiration
Magnetic spring and actuators with multiple equilibrium positions
The design of a car valve where closed position is achieved using permanent
magnets. (http://www.launchpnt.com/portfolio/transportation/electromechanical-valve-actuator/)
Image
3
Image
Calculations

?

Pyro Valve (D10 mm plunger)
Explosive pressure at detonation
Explosive pressure at detonation
Force on D10 mm plunger
650 PSI
4481584 Pa
1407 N (143 kg)
Permanent Magnets
Magnet of choice
MIN number for 143 kg off pull force
Length of 54 magnets
Extra length ~15 mm, or 3 magnets
D10 mm, 5 mm thick, N42 grade, 1.7 kg pull off force
54
270 mm
285 mm
Electromagnets
Estimated D10 mm core, 3000 turns
350 N
(on-line tool used http://www.daycounter.com/Calculators/Magnets/Solenoid-Force-Calculator.phtml)
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Calculations

Piezo electric motor
Largest available
600 N
(http://www.piezo-motor.net/pdf/Piezo_Motor_High_Load_PiezoWalk_Non_Magnetic.pdf)

?
Thermal decomposition
Limit to reversal of process, max pressure at 100 degC (limitation of fuel) would require over
1200 degC for CO2 partial pressure to exceed 4 MPa at pressure of 100 degC and 40 MPa CO2
would be slightly below super critical conditions, so potentially unreliable expansion.
Shape Memory Alloys
Already being investigated by Murray, J. et al. in the paper A Shape Memory Alloy Actuated
Satellite Isolation Valve.

Spring
Wire D 4mm, OD 10mm, free length 100 mm, active coils 15, Stainless 17-7 A313 1063 N
Wire D4 mm, OD10 mm, free length 100 mm, active coils 15, Stainless 17-7 A313 1401 N
(on-line tool used http://www.acxesspring.com/spring-calculator.html)
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Animation (piston shown transparent)
Animation (piston shown transparent)
Animation (piston shown transparent)
Assembly
Simple assembly procedure
1st step. Push the piston and the spring in the housing and lock with the
piezoelectric elements.
2nd step. Screw on the inlet/outlet housing.
Image
7
Image
Redundancy
Three step redundancy
Only one piezo element has to be triggered to release the piston.
Two or one piezo element configurations are possible, then the redundancy would
reduce to two or one.
(The gap size is exaggerated in the illustration.)
Piezo
element
Piston
Gap
8
Benefits and risks
Benefits
Straight forward assembly process.
The energy is introduced in the system at the assembly process.
The valve is triggered by an electric impulse.
Up to three step redundancy built in.
Luer slip arrangement distributes impact energy over a larger
surface as a shear stress instead of compression stress.
Reduced impact from back pressure by larger seal surface area.
Risks
An ultra heavy impact might trigger the valve.
Luer slip (6% taper) connection
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Prize money usage and timeframe
Prize money usage
The price money will be used to conduct a desktop study or to
develop a technology demonstrator.
The complexity of the technology demonstrator will depend on
the price money awarded.
Timeframe
We are looking forward to deliver a desktop study or a
technology demonstrator within 6 to 9 months depending on the
complexity.
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Track record
Successfully completed numerous high value projects with a number of
clients and partners including Rolls-Royce, Airbus and BAE Systems
Please see our capabilities brochure and case studies here:
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Thank you.
For further information please contact or visit:
Email: v.krumins@amrc.co.uk, s.hyde@amrc.co.uk
Tel: 0114 222 6312, 0114 222 9577
web: amrc.co.uk
Twitter: @theAMRC
Confidential. © 2015 AMRC with Boeing.