X-Virus-Scanned: clean according to Sophos on Logan.com X-SpamCatcher-Score: 1 [X] Return-Path: Received: from [68.202.132.19] (account marv@lancaironline.net) by logan.com (CommuniGate Pro WEBUSER 5.1.3) with HTTP id 1692422 for lml@lancaironline.net; Tue, 19 Dec 2006 17:52:11 -0500 From: "Marvin Kaye" Subject: Re: [LML] Re: Tubing To: lml X-Mailer: CommuniGate Pro WebUser v5.1.3 Date: Tue, 19 Dec 2006 17:52:11 -0500 Message-ID: In-Reply-To: <458817FE.4060300@yahoo.com> References: <458817FE.4060300@yahoo.com> MIME-Version: 1.0 Content-Type: text/plain;charset="iso-8859-1";format="flowed" Content-Transfer-Encoding: 8bit Posted for Earl Schroeder : Colyn, I used the standard 37 deg flare for all metal tubing connections. The failure mode is tubing breakage in the area of the ferrules in swagelok type fittings - caused usually by over tightening - either in the initial installation or after maintenance and re tightening. The ferrules actually cut the tubing into and any vibration causes the failure sooner. The torque required to properly tighten a swagelok is so low that it is very easy to give it another 'hitch'. Six flats is the absolute max. On a re tighten, finger tight and then just a bit more. Eventually, the fitting needs to be replaced depending on the number of re makes and a visual inspection of the tubing deformation. [this causes the tubing to be a bit short and probably the entire run has to be replaced] IMHO, a proper flare is much superior in our aircraft applications. Earl colyncase on earthlink wrote: > > /I do not have any metal 'compression' fittings in my Lancair. I did use > some nylon types in the static system but the plastic tubing withstands > vibration much better IMHO./ > // > Earl, > what DID you use instead of compression fittings? > ...and exactly what is the failure mode? breakage or loosening? > > Colyn