Engineering
&
Testing Services
Aerofit, Inc. APT Laboratory
1425 South Acacia Avenue Fullerton, CA 92831
Main: 714-521-5060 Fax: 714-535-9862 www.aerofit.com
Aerofit Products was formed on September 5, 1968 and APT Laboratories was
established as a hydro-mechanical testing laboratory in March 1972.
In March 2004 Aerofit Products and APT were acquired by the present owners
and renamed Aerofit, Inc.
Aerofit and APT have grown into one of the largest suppliers of standard and
spe-cialty fittings in the world. Our manufacturing and testing facilities now
encom-pass over 67,000 square feet.
Aerofit designs, manufactures and tests thousands of parts for application in
mili-tary aerospace, commercial aerospace, marine and nuclear markets. In addition to
proprietary parts, we also produce parts to customer specifications, and industry
standards.
Our goal is to supply our customers with economical, high quality fluid fitting
sys-tems and information through a modern production facility and responsive
cus-tomer support network.
Since it was founded, Aerofit has demonstrated its commitment to quality through
continuous improvement in its production and product support processing.
Topic
Page
Engineering & Testing Services --- 4 & 5
Damped Wave Impulse Testing --- 6
Sine Wave Impulse Testing --- 7
Flexure Fatigue Testing --- 8 & 9
Proof & Burst Hydraulic Pressure Testing --- 10
Water Pressure Testing --- 11
Pneumatic Pressure Testing --- 11
Salt Spray Testing --- 12
Stress Corrosion Testing --- 12
Mechanical Strength Testing --- 13
Test Specimen Cross Sectioning & Mounting --- 13
Microscopic Examination & Documentation --- 14
Test Program Management --- 14
Engineering Services
Our technical staff consists of:
• Research, Design and Development Engineers • Computer Assisted Design (CAD) Draftspersons • Laboratory Test Engineers
• Laboratory Technicians
Our unique technical abilities allow us to create mutually beneficial working
relationships with our customers in the areas of:
• Application Design • Product Design
• Installation Tool Design • Gage Design
• Feasibility Studies
• Qualification Testing Programs
• Post-manufacturing Functional Testing Programs
For more than 35 years we have actively participated in several professional engineering organiza-tions such as the Society of Automotive Engineers (SAE) G-3 Committee, Aerospace Couplings, Fittings, Hose and Tubing Assemblies and the International Standard Organization (ISO) TC/20 and SC/10 Committees
Testing Services
APT Laboratory is a fully functional Hydro-Mechanical test facility, provid-ing qualification, verification and perfor-mance testing of fittings, tube assemblies and hydraulic components.
In addition to standardized hydraulic test-ing, our staff of experienced engineers and technicians can provide guidance for product design and evaluation, detailed test plans, procedures and formal test re-ports, all of which can be specifically tai-lored to your applications.
Some of the tests we conduct include:
• Damped wave impulse test per ARP 603 to 8,000 PSI operating pressure with a peak pressure of 12,000 PSI
• Sine wave impulse test per AS4265 to 30,000 PSI peak pressure • Square wave impulse testing to 12,000 PSI peak pressure
• Flexure fatigue test per ARP 1185 and ISO 7275 up to 8,000 PSI operating pressure
• Hydrostatic pressure test (proof and burst) to 40,000 PSI with MIL-PRF-83282 hydraulic fluid. • Water pressure test up to 15,000 PSI
• Pneumatic pressure test with nitrogen up to 8,000 PSI • Salt spray aging
• Stress Corrosion
• Joint strength (Tensile) testing of tube fitting assemblies • Repeated assembly
• Helium leak detection
Damped Wave Impulse Testing
Hydraulic impulse testing is used for qualification and performance evaluation of
hydraulic system components.
Testing for aerospace fitting, tube and hose applications requires pressure peaks above the square wave pres-sure trace. For testing of aerospace fittings and tube assemblies, it is required that the prespres-sure cycle have a sharp peak, well above the nominal operating pressure. This peak or “waveform” is created by the sudden introduction of pressure, that simulates the high-stress cycles encountered on aircraft hydraulic systems.
These pictures show two custom built manifolds and one of three temperature controlled environ-mental chambers where samples can be tested with Damped Wave or Sine Wave Impulse under extreme hot or cold temperatures conditions.
Testing Chamber
Custom Manifolds
Hydraulic Test Unit APT has three test units that can be used for Damped
Wave Impulse Testing. Each consists of a hydraulic power unit, control panel, Tektronix oscilloscope, shock tube with transducer and custom built manifolds for mounting a wide variety of fittings and tube assemblies to be tested in an temperature controlled environmen-tal chamber. Tests are run in accordance to ARP 603.
Sine Wave Impulse Testing
The Sine Wave is another form of hydraulic impulse testing, which differs from the Damped Wave method in several ways. The waveform is created electronically by the use of a wave form generator, which is connected to an electronically controlled hydraulic valve located on the test machine. This produces a waveform that is more consistent and easier to reproduce from one test to another. The Sine Wave makes smooth transitions at the peaks, which enables its use at extremely high pressures, and has the capability of being run at a much higher frequency, thus reducing the test time required.
APT has one test unit that can be used for Sine Wave Impulse Testing. This is a variable-wave Impulse machine suitable for qualification testing per AS4401 to 30,000 PSI. Custom built mani-folds allow a wide variety of fittings and tube assemblies to be tested in an environmentally con-trolled chamber.
This is a fixed frequency Sine Wave “wave-form” as seen on an oscilloscope. The lower waveform represents the input signal from the signal generator and the upper wave-form represents feedback of the test signal from the transducer.
Another view of a temperature controlled environmental chamber with a liquid nitrogen feeder tank attached. Specific test parameters may require soaking at tempera-ture before, at intervals during or after other mechanical testing.
Sine Wave “Waveform” Temperature Chamber
Flexure Fatigue Test
Mechanical Flexure Testing is a method of determining and classifying the fatigue
strengths of re-connectable or permanent hydraulic tube joints.
The test specimen typically consists of a fitting joined to a specified length of straight tubing. The assembly is then fitted with strain gages which are used to determine the amount of deflection required to generate the required load or bending stress.
The opposite end of the specimen is deflected by moving the boring head off center until the desired bending stress in the tube assembly is reached. This is determined by the strain gage equipment. Option-ally, the sample may be setup by deflection at a specified length. The fitting being tested is rigidly mounted in the manifold that
allows the assembly to be pressurized to the operating pressure. Internal pressure is maintained throughout the duration of the
test. Rigid Manifold
Strain Gage Measuring Equipment Strain Gage Wires Tubing Test Specimen Dial Indicator to Measure Deflection Boring Head
Flexure Fatigue Test (Continued)
Once the setup is completed the sample is pressurized in a range of 1,800 to 3,500 CPM and the boring head is rotated at a test cycle rate. All param-eters are maintained until the specimen fails or meets the number of cycles required by the applicable specification.
Specimens Can Also Be Tested in Extreme Hot or Cold Temperature Conditions
Fittings are Tested in All Shapes and Sizes Rotating End
Fixed End with Test Fitting
Proof & Burst Hydraulic Pressure Test
APT’s pressure test machine is capable of achieving and maintaining 40,000 PSI us-ing MIL-PRF-83282 Hydraulic Fluid. This unit is utilized for qualification testing to commercial and military requirements.
Proof Pressure Test:
Most specifications require samples to be pressur-ized at twice the rated system pressure, without leakage for three minutes. Samples are often proof pressure tested prior to other forms of testing to insure their integrity.
Burst Pressure Test:
The burst test in SAE-AS18280 and similar specifi-cations require the test samples to withstand burst pressure, without leakage or rupture, for five min-utes. For operating pressures of 5,000 PSI and less, the burst pressure is four times the rated operating pressure. For 8,000 PSI systems the burst pressure is three times the operating pressure. Samples are often pressurized to failure to determine ultimate burst pressure and failure mode, as shown.
Failure Pressure Test Chamber
Other Testing Capabilities
Water Pressure Test
APT Laboratory has the capability of water pressure testing hydro-mechanical components in a variety of configurations to 15,000 PSI. Distilled water is often used to proof pressure test assemblies to avoid expensive cleaning pro-cesses after testing.
Chamber is 2 feet by 2 feet by 1.5 feet deep.
Pneumatic Pressure Test
The test sample is fitted with the appro-priate test adapter and is installed onto a flexible hose. The line is purged of air using Nitrogen gas. The test sample is then submerged in water and pressur-ized with Nitrogen gas until the speci-fied test pressure is achieved. This pres-sure is maintained for a specified period of time and is monitored for leakage as indicated by bubbles escaping from the test sample.
Pressure Test Chamber Pressure Gage Test Sample Immersion Chamber Gas Booster Pneumatic Pump
Other Testing Capabilities
Salt Spray Testing
Salt Spray testing is performed to the test parameters of ASTM-B-117. Testing is available for exposure times varying from a few hours up to thousands of hours. Salt Spray testing is generally used in conjunction with other tests such as flexure and / or impulse. Specific test parameters may require salt spray exposure before, at intervals during or after other mechanical testing.
Stress Corrosion Testing
Stress Corrosion Testing is conducted using a constant load deflection test fix-ture. Typically specimens are loaded to various levels of applied stress using a mechanical fixture and measured using a strain gage. It is common to test several specimens at various stress levels.
The effects of corrosion on stressed specimens are introduced using salt spray cabinets. The amount of stress, time exposed to corrosion and the concentration of salt is determined by the test parameters.
Salt Spray Chamber
Multiple Specimen
Other Testing Capabilities
Mechanical Strength Testing
Joint strength testing is conducted in accordance with AS18280 and similar procurement specifications. Axial load testing of test specimens and assemblies in either tension or compression can be performed in-cluding fabrication of specialized test fixtures.
Tube twisting, torque testing, repeated assembly and disassembly testing.
Test Specimen Cross Sectioning
& Mounting
A number of different sectioning tech-niques are available to support failure analysis, weld evaluation, microhardness testing and mechanical testing. Precision sectioning can be performed on small parts or for parts requiring examination of small areas of interest.
Digital Recorder Load Cell Printer Adapters Test Specimen
Other Testing Capabilities
Microscopic Examination & Documentation
Cross sections can be cut from areas of interest in the sample being evaluated and the physical configuration can be examined at various magnifications. Any findings can be documented using digital photography.
Test Program Management
In addition to our inhouse capabilities we have close working relationships with several other accredited local laboratories where we can outsource testing. Our expert staff manages and monitors such outsourcing with detailed instructions and on site observations of the tests being run. All data is closely evaluated and reported. Some of the types of tests we have outsourced are:
• Vibration • Fatigue • Fire
• Lightning Strike • Thermal Shock
The End Product
The Report
The “Product” is the test report which outlines the methods used and the results obtained for the products, assemblies, or systems tested.
Since its inception in 1972 APT Laboratory has conducted test programs for major aerospace companies such as:
• Boeing • Lockheed Martin • Cessna • Learjet • EADS • Gulfstream • Raytheon Aircraft • Dehavilland • Bell Helicopter
• Northrop Grumman Ship Sys. • Northrop Grumman Corp. • Airbus • Hawker Beechcraft • Bombardier • Fine Tubes • Sandvik • Specitubes • Adel Wiggins • Shur-lok • Alcoa • Hydraflow • GE • JPL • Goodrich A.G. • BAE
In addition to standardized hydraulic testing, our staff of experienced engineers and technicians can provide guidance for:
• Product design and evaluation • Detailed test plans