Revised Draft JTP for Hydraulic & Pneumatic Actuators

National Technical Systems / Elwin Jang / 916-392-6163

April, 2001

Overview of Joint Test Protocol

• The Entire JTP is composed of 3 Parts– Part I – Material Testing

– Part II – Component or Rig Testing

– Part III – Flight Testing

• This draft JTP is composed of Parts I & II – Part III will be prepared at a later date

Test Types

• Standard Test – Joint Test-Service & OEM agreed test

• Extended Test – Joint Test-Service or OEM component-specific test

Part I – Coatings & Substrates

• Primary Coating - WC/Co-Cr – Secondary Coatings – WC/Co, Tribaloy T-400,

Cr3C2/NiCr

• Primary Substrates: 4340 ESR steel, PH15-5 SS– Secondary Substrates: HP9-4-30 steel, PH17-4

SS, & Ti-10-2-3 titanium

Material Testing

• Fatigue, Axial (1980 specimens vs. 720 specimens for LG)

• Corrosion (rod specimens)– Neutral Salt Fog (190 specimens vs. 135 specimens for LG)– Sulfur Dioxide– Anodic Polarization (extended test)– Galvanic (extended test)

• Immersion – Liquid and grease• Fretting & Oscillating Wear (no need for follow-on test)

Material Testing (continued)

• Gardner Impact (extended test)• Functional Hydraulic Rod/Seal (draft PWS)• Chemical Stripping• 4-Point Bending (extended test)• Quality Control Tests

– Microhardness– Structural Analysis– Oxide Content; Porosity; Unmelted Particles, Interface

Material Testing (continued)

• Quality Control Tests (continued)– Bond Strength– Bend– Almen Strip

Component or Rig Testing

• Neutral Salt Fog• Sand & Dust• Humidity • Vibration• Impulse• Fluid Immersion• Functional Hydraulic

– Endurance– Leakage– Temperature Shock

Appendix A

• Douglas Aircraft Spec. PS-17134, Qualification Test Procedure for Sterer P/N 70795-24

• “C-17 Door Locking Actuator Assembly”• This utility actuator spec. has valuable tech info and

administrative procedure that can be tailored to other utility actuators and flight control actuators

Draft PWS for Functional Hydraulic Rod/Seal Testing

Greene Tweed PWS

Coating WC/Co-Cr, WC/Co, WC/Co-Cr, WC/Co,

T-400, EHC T-400, EHC, Cr3C2/NiCr

Finish 2-5 Ra 2-5 Ra & SuperfinishSubstrate 4340 steel or equivalent 4340 steel or equivalentDuty Profile Flight control Flight control & utility

Seals Greene Tweed Several major seal suppliers

Sideload None 72 lbs.

Draft PWS for Functional Hydraulic Rod/Seal Testing (cont.)

Greene Tweed PWS

Seal/Rod

Combination 21 120 (may reduce to 60)

Test Temp 120F 120F (may change to: room-

180F-200F)

Leakage at Thermal None -40F to 225F (for Extremes nitrile seal)

-40F to 275F (for Teflon seal)

Future Work

• Will revise the draft JTP & the PWS, after receiving your comments

• PWS specifies testing seals from two major seal suppliers – To avoid appearance of conflict of interest, consider soliciting

independent labs or third party seal suppliers for testing– They may not have available hydraulic test equipment &

associated temp control systems. Thus might ask for higher price