Design and Test
FAR-0004
Revision --
May 12, 2010
By: Mark Holthaus
FAR-0004
Friends of Amateur Rocketry, Inc.
Page 1 of 17
Revision Status
Revision
Date
Letter
-05/12/2010
FAR-0004
Authority
M. Holthaus
Description
First Release
Friends of Amateur Rocketry, Inc.
Page 2 of 17
Index
Reference Documents .............................................................................. 4
Definition of Terms .................................................................................... 5
Rocket Design Review Checklist .............................................................. 6
Rocket Static Firing Design Review Checklist .......................................... 7
Ground Support Equipment Design Review Checklist ............................. 8
Tank Hydrostatic Test Procedure............................................................ 10
Water Flow Test Procedure .................................................................... 11
Injector Water Flow Test Procedure ....................................................... 12
Rocket Valve Test Procedure ................................................................. 13
Leak Test Procedure ............................................................................... 14
Rocket Static Test Preparation Procedure .............................................. 17
FAR-0004
Friends of Amateur Rocketry, Inc.
Page 3 of 17
Reference Documents
Document Number
FAR-0004
Document Name
Friends of Amateur Rocketry, Inc.
Page 4 of 17
Definition of Terms
Term
FAR-0004
Definition
Friends of Amateur Rocketry, Inc.
Page 5 of 17
Rocket Design Review Checklist
1.
2.
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30.
31.
Vehicle stability analysis (Center-of-Gravity versus Center-ofPressure)
Fin attachment strength
Structural strength
Thrust structure strength.
Launch lugs (Minimum 2)
Launch lug strength
Fuel tank hydrostatic test (>125% Operating Pressure)
Oxidizer tank hydrostatic test (>125% Operating Pressure)
Pressurization system tank analysis (>125% Operating Pressure)
Altitude analysis
Vehicle weight
Vehicle dimensions
Static firing test.
Water flow test.
Injector water flow test.
Main valve open and close.
Propellant tank remote controlled vents.
Propellant tank pressure relief valves.
Low-point, propellant tank fill and drain valves.
Remote controlled pressurant fill quick disconnect.
Remote controlled pressurant on and off valve.
Propellant tank pressurization, check valves.
Propellant tank pressurization diffuses.
Material and propellant compatibility evaluation.
Components cleaned for propellant.
Pressure transducers on propellant tanks.
Pressure transducer on pressurant tank.
Develop countdown sequence.
Develop abort sequence.
Develop prelaunch procedures.
Develop abort procedures.
FAR-0004
Friends of Amateur Rocketry, Inc.
Page 6 of 17
Rocket Static Firing Design Review
Checklist
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5.
6.
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25.
Mounting structural strength
Rocket motor mounting strength.
Fuel tank hydrostatic test (>125% Operating Pressure)
Oxidizer tank hydrostatic test (>125% Operating Pressure)
Pressurization system tank analysis (>125% Operating
Pressure)
Injector water flow test.
Water flow test.
Remote controlled main valve open and close.
Propellant tank remote controlled vents.
Propellant tank pressure relief valves.
Low-point propellant tank fill and drain valve.
Remote control pressurant on and off valve.
Propellant tank pressurization check valve.
Propellant tank pressurization diffuser.
Material and propellant compatibility evaluation.
Components cleaned for propellant.
Pressure transducers on propellant tanks.
Pressure transducer on pressurant tank.
Load cell on rocket motor.
Pressure transducer on combustion chamber.
Develop countdown sequence.
Develop abort sequence.
Develop pretest procedures.
Develop abort procedures.
FAR-0004
Friends of Amateur Rocketry, Inc.
Page 7 of 17
Ground Support Equipment Design
Review Checklist
1.
Electrical Controls







2.
Computer Control





3.
Computer
Monitor
Keyboard
Mouse
Interface
Software
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
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

4.
5.
Main Valve Open and Close
Fuel Vent Open and Close
Oxidizer Vent Open and Close
Pressurant On and Off
Umbilical Release
High-Pressure Control Valve
Igniter Initiate
Launch sequencing
Abort sequencing
Checkout sequencing
Parameter display
Warnings and alarms
Data archival
Electrical Umbilical
Electrical Extension
 1000-Foot Cable
 Cable Reel
6.
7.
Data Acquisition
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

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Emergency Manual Control
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8.
Rocket Sensors (Pressure, Temperature, Valve Position)
Pad Sensors (Pressure, Valve Position)
Acquisition Unit
Computer with Monitor and Keyboard
Main Valve Close
Fuel Vent Open
Oxidizer Vent Open
Pressurant Off
Fuel Loading
 Tank/Dewar
 Loading Hose
 Hose Wrench
9.
Oxidizer Loading
 Tank/Dewar
 Loading Hose
 Hose Wrench
FAR-0004
Friends of Amateur Rocketry, Inc.
Page 8 of 17
Ground Support Equipment Design
Review Checklist
10. Pressurant Loading




Remote Control High-Pressure Valve
High-Pressure Hose
High-Pressure Bottle
Pressurant Umbilical with Remote Control Quick Disconnect
11. Pneumatic Pressurant
 Low-Pressure Regulator
 Low-Pressure Hose
 Pressure Bottle
12. Launch Rail



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13.
14.
15.
16.
Support Tower
Tower Base
Rail Guide
Rocket Support Bracket
Flame Deflector
Launch Pad Power
Electrical Control Power
Control software
 Countdown sequence
 Abort sequence
 Checkout sequence
17.
18.
19.
FAR-0004
Friends of Amateur Rocketry, Inc.
Page 9 of 17
Tank Hydrostatic Test Procedure
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13.
Check the tank for dents and damage. If the tank is dented or
damaged, do not do this test.
WARNING: HIGH-PRESSURE OPERATIONS. Wear safety
glasses. Limit people handling and standing near the tank when
pressurized.
Completely fill tank with water. WARNING: Do not leave any air
pockets in the tank. Fill from the bottom of the tank and vent the
air from the top.
Check and tighten all fittings to make sure they are not leaking.
Using a water hand pump, pump the tank pressure up to 150% of
the operating pressure. WARNING: If the tank pressure is not
rising while pumping, the tank is expanding and may rupture.
STOP PUMPING.
Hold the pressure for 3-minutes.
Relieve the pressure.
Pressurize and relieve the tank two additional times using steps 4
through 6.
If the tank bursts, springs a leak, or deforms: the tank is unusable.
Drain the tank of water.
Rinse the tank with isopropyl alcohol.
Force air through the tank to dry out.
When you can do longer smell alcohol in the tank, it is dry.
FAR-0004
Friends of Amateur Rocketry, Inc.
Page 10 of 17
Water Flow Test Procedure
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Calculate fuel and oxidizer volume flow rate for the rocket
engine.
Calculate the flow duration based on propellant tank volumes
and the propellant volume flow rate.
Calculate fuel and oxidizer orifice size with equivalent water
volume flow. Please Note: When using water with full feed
pressure drop to the atmosphere across the orifice, the water
will cavitate in the orifice. Utilize a Cd of 0.611 for a cavitating
orifice.
Machine water flow test fuel and oxidizer feedline orifices.
Setup test stand.
Setup data acquisition system to record fuel, oxidizer, and
pressurant tank pressures.
Remove rocket motor.
Install orifices in place of the injector.
Perform rocket leak test.
Perform rocket valve test.
Mount the rocket in the test stand.
Load pressurant.
Load water into propellant tanks.
Start data acquisition system.
Perform 3-second countdown.
On 0-count open main valves.
Stop the data acquisition when all the water runs out.
From the recorded data, time the water flow from main valve
open until the water runs out.
Compare the water flow duration to the calculated flow
duration.
From the recorded data, check the pressure regulator output
pressure to see if the regulator is supplying the expected
pressure. If the pressure drops too low, the regulator is not
keeping up with the expected flow rate.
Dismount rocket from test stand.
Remove main ball valves from the rocket.
CAUTION: FOR CRYOGENIC PROPELLANTS. Take apart
the ball valves and thoroughly dry all internal parts. Water on
the inside of the ball valve can freeze solid when using
cryogenic propellants and cause a hang fire.
FAR-0004
Friends of Amateur Rocketry, Inc.
Page 11 of 17
Injector Water Flow Test Procedure
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Calculate fuel and oxidizer volume flow rate for the rocket engine.
Calculate the equivalent water weight
Connect a water source to the fuel side of the injector.
Start the water flowing. Adjust the flow rate until in input pressure
is 20-psig.
Spray and collect the water into a bucket for 5-minutes.
Weigh the amount of water.
Perform steps 2 through 4 for two more times.
Calculate an average orifice size.
Connect a water source to the oxidizer side of the injector.
Start the water flowing. Adjust the flow rate until in input pressure
is 20-psig.
Spray and collect the water into a bucket.
Time the water until the bucket is full.
Record the time and input pressure.
Weigh the amount of water.
Record the water weight.
Perform steps 8 through 10 for two more times.
Connect water to both the oxidizer and fuel sides of the injector.
Visually check the impingement pattern from the injector holes.
Water streams emanating from the fuel and oxidizer orifice pairs
should impinge at expected angles.
Dry the injector.
Calculate water mass flowrate for each measurement.
Calculate the Cd for the orifices based on the number of injector
holes, injector hole size, water flow test feed pressure, and water
mass flow rate. The resulting Cd for the orifices should be
approximately 0.8.
Adjust orifices size and angle if the results are not what are
expected and redo water flow testing.
23.
FAR-0004
Friends of Amateur Rocketry, Inc.
Page 12 of 17
Rocket Valve Test Procedure
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Setup electrical ground support equipment.
Setup mechanical ground support equipment.
Connect the electrical umbilical between the electrical ground
support equipment and the rocket.
Connect the pressurant umbilical between the mechanical
ground support equipment and the rocket.
Place all switches in the closed position.
Turn on the pneumatic pressure to 100-psi.
Turn the electrical ground support equipment power on.
Command main valve open.
Command main valve closed.
Command fuel tank vent open.
Command fuel tank vent closed.
Command oxidizer tank vent open.
Command oxidizer tank vent closed.
Command pressurization valve open.
Command pressurization valve closed.
Command pre-pressurization valve open.
Command pre-pressurization valve closed.
Command umbilical to disconnect.
FAR-0004
Friends of Amateur Rocketry, Inc.
Page 13 of 17
Leak Test Procedure
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To start the leak test insure the main valve is closed.
Verify the helium pressurization system is at ambient pressure.
WARNING: HIGH-PRESSURE. Have a minimum crew near the
tanks and wear safety glasses when tanks are pressurized.
Always work in teams of two.
Oxidizer tank pressure decay test.
Connect a low-pressure helium pressurizer to the oxidizer fill and
drain port.
Open the oxidizer fill and drain valve.
Pressurize the oxidizer tank to 100-psi.
Close the oxidizer fill and drain valve.
Relieve the pressure on the helium source line.
Monitor oxidizer tank pressure. If the pressure decreases by
more than 1-psi in 5-minutes, there is a leak that needs to be
fixed. Perform a bubble test on oxidizer fittings and valves.
Monitor the pressurant system pressure. If the pressure
increases by more than 1-psi in 5-minutes, there is a leak in the
oxidizer tank pressurant check valve.
If the leak test is successful, leave the oxidizer tank pressurized.
Disconnect the low-pressure helium pressurizer from the oxidizer
fill and drain port.
Fuel tank pressure decay test.
Connect a low-pressure helium pressurizer to the fuel fill and
drain port.
Open the fuel fill and drain valve.
Pressurize the fuel tank to 100-psi.
Close the fuel fill and drain valve.
Relieve the pressure on the helium source line.
Monitor fuel tank pressure. If the pressure decreases at more
than 1-psi for 5-minutes, there is a leak that needs to be fixed.
Perform a bubble test on fuel fittings and valves.
Monitor the pressurant system pressure. If the pressure
increases by more than 1-psi in 5-minutes, there is a leak in the
fuel tank pressurant check valve.
If the leak test is successful, leave the fuel tank pressurized.
Disconnect the low-pressure helium pressurizer from the fuel fill
and drain port.
Pressurant system pressure decay test.
Connect a low-pressure helium pressurizer to the pressurant fill
FAR-0004
Friends of Amateur Rocketry, Inc.
Page 14 of 17
Leak Test Procedure
23.
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1.
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8.
and drain port.
Open the pressurant fill and drain valve.
Pressurize the pressurant tank to 100-psi.
Close the pressurant fill and drain valve.
Relieve the pressure on the helium source line.
Monitor fuel pressurant pressure. If the pressure decreases at
more than 1-psi for 5-minutes, there is a leak that needs to be
fixed. Perform a bubble test on pressurant fittings and valves.
Open the pressurant fill and drain valve to relieve the pressurant
tank pressure.
Close the pressurant fill and drain valve.
Open the oxidizer fill and drain valve to relieve the oxidizer tank
pressure.
Close the oxidizer fill and drain valve.
Open the fuel fill and drain valve to relieve the fuel tank pressure.
Close the fuel fill and drain valve.
Rocket motor pressure decay test.
Clamp a plug on the exit of the rocket nozzle.
Connect a low-pressure helium pressurizer to the rocket motor
plug valve.
Open the plug valve and pressurize the rocket motor to 100-psi.
Close the plug valve.
Relieve the pressure on the helium source line.
Monitor the rocket motor pressure. If the pressure decreases at
more than 1-psi for 5-minutes, there is a leak that needs to be
fixed. Perform a bubble test on fittings and valves.
Open the plug valve to relieve the rocket motor pressure.
Remove the rocket nozzle plug.
End of Leak Test
Bubble Soap Test
If the pressure decay test fails, perform the following:
Prepare a 5% soap and water solution in a spray or squirt bottle.
With plumbing pressurized perform the following steps.
Spray soap solution on tube and pipe joints.
Spray soap solution on fitting joints.
Spray soap solution on valve joints.
Spray soap solution on valve body joints and stems.
Spray soap solution on manifold joints.
FAR-0004
Friends of Amateur Rocketry, Inc.
Page 15 of 17
Leak Test Procedure
9. Spray soap solution on tank joints.
10. Look for bubbles forming. If bubbles are forming, tighten the joint.
If the bubbles persist, re-connect the joint using new pipe tape,
conical seals, or O-rings. If the bubbles are forming on a valve
body seams, replace the valve.
11. Spray soap solution on your finger and wipe over the output ports
of the following:
12. Wipe the fill and drain valve output.
13. Wipe the relief valve output.
14. Wipe the manual vent-valve output.
15. Wipe the remote control vent-valve output.
16. Look for bubbles forming at the valve output. If bubbles are
forming, replace the valve.
17. If the rocket motor is pressurized, spray soap solution on rocket
motor joints.
18. Look for bubbles forming. If bubbles are forming, replace rocket
motor body O-rings.
FAR-0004
Friends of Amateur Rocketry, Inc.
Page 16 of 17
Rocket Static Test Preparation Procedure
1.
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6.
7.
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18.
Fuel tank low pressure, pressure decay test.
Oxidizer tank low pressure, pressure decay test.
Main valve open and close test.
Fuel tank vent command open and close test.
Oxidizer tank vent command open and close test.
Pressurization valve command open and close test.
Pressurization system low pressure, pressure decay test.
Pre-pressurization valve command open and close test.
Inspect catalyst.
Load reloads.
Install nozzle.
CAUTION: Make sure all seals are in place and all closures are
firmly in place.
Calibrate load cell.
Verify pressure transducer function.
FAR-0004
Friends of Amateur Rocketry, Inc.
Page 17 of 17