Jump to content

Recommended Posts

Posted

The most common hardness is 75 in this material but any of those hardness will be fine. Softer might be better; harder o-rings are typically designed to hold back high pressure (I use the 90 durometer version to routinely hold back 3,500+ psi) and the softer ones would seat easier.

Also note that "color" doesn't necessarily equate to material. Many fluorosilicone o-rings are black like nitrile/buna.

The large fuel cap o-rings are also readily available though I can't remember the number off the top of my head. I have spares at the hangar and can check the number sometime if anybody cares. You should change those at the same time as they get surface cracking after a while. They only cost like $1 each from a few sources.

Cnoe

Sent from my iPad using Tapatalk

Posted

338 is the larger size for the cap      A bit of Jet Lube after some emery cloth to clean things up.   Should also get a couple of new cotter pins.   If it is the first time you are doing them, it may be that the certified mechanic used the wrong size cotter pin.   Some may say a stainless cotter pin it possibly better for the type of liquid environment they are going in. You are inspecting them every time you fly... right.

  • 3 weeks later...
Posted

I tried to order the 338 flourosilicone o-rings...out of stock!! LOL

 

Anyone have four 338 flourosilicone  o-rings for sale?

  • 5 months later...
Posted

What are the legal ramifications of using these?  Is there any approved use in certified aircraft that can be used for justification?

John Breda

Posted

I'm no attorney and it's just my $0.02 but I believe this would be considered a "standard part" when installed in a non-critical application such as this. Refer to AC21-29 (http://www.airweb.faa.gov/Regulatory_and_Guidance_Library/rgAdvisoryCircular.nsf/0/65e4b3e6dea39d4886256a650070a095/$FILE/ac21-29Chg1.pdf). Many domestic manufactured o-rings are mil-spec already.

I would not, however, recommend using standard o-rings in fuel servos, etc. for liability reasons.

Sent from my iPad using Tapatalk

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.