X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from fed1rmmtao104.cox.net ([68.230.241.42] verified) by logan.com (CommuniGate Pro SMTP 5.2.1) with ESMTP id 2844725 for flyrotary@lancaironline.net; Sat, 12 Apr 2008 10:52:45 -0400 Received-SPF: none receiver=logan.com; client-ip=68.230.241.42; envelope-from=alventures@cox.net Received: from fed1rmimpo01.cox.net ([70.169.32.71]) by fed1rmmtao104.cox.net (InterMail vM.7.08.02.01 201-2186-121-102-20070209) with ESMTP id <20080412145202.QOID16991.fed1rmmtao104.cox.net@fed1rmimpo01.cox.net> for ; Sat, 12 Apr 2008 10:52:02 -0400 Received: from BigAl ([72.192.137.74]) by fed1rmimpo01.cox.net with bizsmtp id Ces31Z00E1cVYgg03es3Wi; Sat, 12 Apr 2008 10:52:04 -0400 From: "Al Gietzen" To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Re: adding a tubing bead Date: Sat, 12 Apr 2008 06:55:34 -0800 Message-ID: <000001c89cad$42b03aa0$6401a8c0@BigAl> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0001_01C89C6A.348CFAA0" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.6626 Importance: Normal In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3198 This is a multi-part message in MIME format. ------=_NextPart_000_0001_01C89C6A.348CFAA0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Subject: [FlyRotary] Re: adding a tubing bead =20 Al, you could do like Tracy did on his original, wrap a string coated = with epoxy around the tube. I hope that idea it still works, as I did mine = that way. JohnD Yes; but what epoxy? Most epoxies lose strength rapidly above about = 150F. What keeps the bead in place at 210F when the pressure is the highest? = You would want to use an epoxy that was good to 300F. =20 Whether it works depends on the connection configuration. Just consider = the x-sectional area of the connection, the expected pressure, and the constraints counteracting the force. Some connections don't need a bead = at all. A short coupling hose in a straight line where things are = constrained at both ends needs no bead. The pressure forces offset. A longer hose = with a 90 degree bend needs a bead or the pressure will blow the hose off the connection. =20 Just some rambling thoughts . . =20 =20 Al =20 =20 ------=_NextPart_000_0001_01C89C6A.348CFAA0 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

Subject: [FlyRotary] Re: adding a tubing bead

 

=

Al, you could do like = Tracy did on his original, wrap a string coated with epoxy around the tube.  I hope = that idea it still works, as I did mine that way.  = JohnD

Yes; but what epoxy?  Most = epoxies lose strength rapidly above about 150F.  What keeps the bead in = place at 210F when the pressure is the highest?  You would want to use an = epoxy that was good to 300F.

 

Whether it works depends on the connection configuration.  Just consider the x-sectional area of = the connection, the expected pressure, and the constraints counteracting the = force. Some connections don’t need a bead at all.  A short coupling = hose in a straight line where things are constrained at both ends needs no bead. = The pressure forces offset. A longer hose with a 90 degree bend needs a bead = or the pressure will blow the hose off the connection.

 

Just some rambling thoughts  = . . 

 

Al

 

 

------=_NextPart_000_0001_01C89C6A.348CFAA0--