X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Thu, 05 Jul 2007 15:46:01 -0400 Message-ID: X-Original-Return-Path: Received: from web82715.mail.mud.yahoo.com ([68.142.201.29] verified) by logan.com (CommuniGate Pro SMTP 5.1.10) with SMTP id 2159512 for lml@lancaironline.net; Thu, 05 Jul 2007 09:52:59 -0400 Received-SPF: none receiver=logan.com; client-ip=68.142.201.29; envelope-from=earleschroeder@yahoo.com Received: (qmail 95166 invoked by uid 60001); 5 Jul 2007 13:52:22 -0000 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=X-YMail-OSG:Received:X-Mailer:Date:From:Subject:To:MIME-Version:Content-Type:Message-ID; b=mcFZtSiVCyNbzM87abrm2tGoAZNltXDFknk9LM/7v9orTDBoQzujEIjzTbsnY+nLyQlak2me33mU3zycU+X9FhAS7snw2++0hMPhq32ez0a5UUUFxgq2t6/80jVlLaGbyLrM8vtsLslyKmUoJtWkH74Ab2W1AgrlKh25SYKnUqM=; X-YMail-OSG: MUV4PMIVM1kl4ZNpBBRf211oKFNBBibBN1Ai.Ws35Th.BPe2 Received: from [75.16.234.192] by web82715.mail.mud.yahoo.com via HTTP; Thu, 05 Jul 2007 06:52:22 PDT X-Mailer: YahooMailRC/651.38 YahooMailWebService/0.7.41.16 X-Original-Date: Thu, 5 Jul 2007 06:52:22 -0700 (PDT) From: Earl Schroeder Subject: Re: [LML] Re: LNC2 hydraulic pump turns on when gear is down at regular intervals??? X-Original-To: Lancair Mailing List MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="0-671167500-1183643542=:93191" X-Original-Message-ID: <643023.93191.qm@web82715.mail.mud.yahoo.com> --0-671167500-1183643542=:93191 Content-Type: text/plain; charset=ascii Bob wrote: I checked all the cylinders first, believing that the dump valve could not leak in one direction only. I've not had a problem with my dump valve nor have I verified it is of the same type of the many I have personal experience with. [30+ yrs in GE chemical business - Lexan plastics] My point is that most ball valves have a 'floating' ball that uses only the downstream seat to seal. So it would be easy to believe that the valve would leak only in one direction. It is my belief that most leaking dump valves are caused by foreign material scratching the seat [something that was left in the lines during construction]. This material probably also causes leaking cylinders. I find it difficult to believe that in a clean installation the dump valve would ever leak in either direction. The pressure rating relates to burst pressures - not sealing ability. Of course, I could be mistaken... Earl --0-671167500-1183643542=:93191 Content-Type: text/html; charset=ascii

Bob wrote:

I checked all the cylinders first, believing that the dump valve could not leak in one direction only.

I've not had a problem with my dump valve nor have I verified it is of the same type of the many I have personal experience with. [30+ yrs in GE chemical business - Lexan plastics]

My point is that most ball valves have a 'floating' ball that uses only the downstream seat to seal. So it would be easy to believe that the valve would leak only in one direction. It is my belief that most leaking dump valves are caused by foreign material scratching the seat [something that was left in the lines during construction]. This material probably also causes leaking cylinders. I find it difficult to believe that in a clean installation the dump valve would ever leak in either direction. The pressure rating relates to burst pressures - not sealing ability. Of course, I could be mistaken... Earl

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