X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Sun, 05 Feb 2012 08:34:41 -0500 Message-ID: X-Original-Return-Path: Received: from nm20.bullet.mail.ac4.yahoo.com ([98.139.52.217] verified) by logan.com (CommuniGate Pro SMTP 5.4.4) with SMTP id 5382394 for lml@lancaironline.net; Fri, 03 Feb 2012 22:36:55 -0500 Received-SPF: none receiver=logan.com; client-ip=98.139.52.217; envelope-from=wfhannahan@yahoo.com Received: from [98.139.52.195] by nm20.bullet.mail.ac4.yahoo.com with NNFMP; 04 Feb 2012 03:36:20 -0000 Received: from [98.139.52.175] by tm8.bullet.mail.ac4.yahoo.com with NNFMP; 04 Feb 2012 03:36:20 -0000 Received: from [127.0.0.1] by omp1058.mail.ac4.yahoo.com with NNFMP; 04 Feb 2012 03:36:20 -0000 X-Yahoo-Newman-Property: ymail-3 X-Yahoo-Newman-Id: 535063.26254.bm@omp1058.mail.ac4.yahoo.com Received: (qmail 91008 invoked by uid 60001); 4 Feb 2012 03:36:19 -0000 DomainKey-Signature:a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=X-YMail-OSG:Received:X-Mailer:References:Message-ID:Date:From:Reply-To:Subject:To:In-Reply-To:MIME-Version:Content-Type; b=EKnXxtRg3Bp74aUuB3plkrwWdb2T+8iiBVWAyDTByRhG9lEfAutIMgjtPY3ggWOvUBv9jfvQvLO9HoJ5DZA8Na1QXzPuBhArgpkbBsO37ueJqFIDx1Yox/RF82NzIMWHxswcVSTONm31UgTTXNFw+aTjbyFyVNZCRpTLaZceweI=; X-YMail-OSG: 3BYIiTMVM1n34G_Yj6pLtyzan7S4V2KRHUTEbymvinQoQqz N56PMkI9DvivaDnUj0AwaqFXWy0PMoIKdN.ZLzu1B0iGGl.mhYBItZrW1rP6 b5sDf39uddVht9tO1ibjCY5IPWZPmbcumthtaxxqbjuMbv6NmrwJ.g156K1A QvfgqCqgVK_TfuqmhmVeJlBpRKnwW5g7TI8E4tYsuk86XUgLFg8kSJfV5aNJ YQClUEaSYvrLdIzhJkiLVXiCSs2BtODS81_OKKt5sHiiLOprVnIDlG.VLDGG h32uQYcRM_6Wx4c8cQ4K4Mt4KOnouc8jlyMqOGFU7LPjf2hBJN33kBXaQtTN dIltRBo2sKc1noc8rsp9vNPFGGoKUYykyaNPRSKWK3OlFUUpgg_agRlupdKK gkmCLmle0Tsd2wEgLPLBE8.ALvyQZBOZDuq.mVeOYahsiKrI8DDDzrZ9Ht3k JY5tNKcqzO3eSLTozeXvUsyXaJ33tePv14SXxxYef58YuqIJcGNAqpA_pZ3d xj2cwGpSP.rjKdrd8 Received: from [97.123.68.40] by web33908.mail.mud.yahoo.com via HTTP; Fri, 03 Feb 2012 19:36:19 PST X-Mailer: YahooMailWebService/0.8.116.338427 References: X-Original-Message-ID: <1328326579.86112.YahooMailNeo@web33908.mail.mud.yahoo.com> X-Original-Date: Fri, 3 Feb 2012 19:36:19 -0800 (PST) From: Bill Hannahan Reply-To: Bill Hannahan Subject: 320/360 Hydraulic Pressure Switch X-Original-To: Lancair Mailing List In-Reply-To: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="-564810535-920033383-1328326579=:86112" ---564810535-920033383-1328326579=:86112 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable =C2=A0=0AChris, you said, =E2=80=9C=C2=A0Pressure switch setting=C2=A0<=0Aa= djustable relief valve setting=C2=A0< thermal relief valve setting=E2=80=9D= =0A=C2=A0=0AWhat is the =E2=80=9Cadjustable relief valve setting=E2=80=9D i= n psi? =0A=0A=0AHow is=0Ait adjusted?=0A=C2=A0=0A=C2=A0=0ARegards,=0ABill H= annahan=0A=0Awfhannahan@yahoo.com=0A=0A=0A________________________________= =0A From: Chris Zavatson =0ATo: lml@lancaironline= .net =0ASent: Friday, February 3, 2012 11:10 AM=0ASubject: [LML] Re: 320/36= 0 Hydraulic Pressure Switch=0A =0A=0ABill,=0AThe TRV is selected based on s= ystem operating pressures and not pump capabilities. =C2=A0It is there to p= rotect your cylinders and lines and anything else downstream of the poppet = valves=C2=A0in case of excessive=C2=A0thermal heating.=C2=A0=C2=A0If we ran= our systems at higher pressures, we would need a different TRV.=0A=C2=A0Pr= essure switch setting=C2=A0< adjustable relief valve setting=C2=A0< thermal= relief valve setting=0A=C2=A0=0AChris Zavatson=0AN91CZ=0A360sd=0Awww.N91CZ= .net=0A=C2=A0=0AOn Feb 3, 2012, at 5:02 AM, Bill Hannahan wrote:=0A =0A>=C2=A0=0A>Chris, thanks for the feedback and the work y= ou did.=0A>=C2=A0=0A>I sense a contradiction in this statement;=0A>=C2=A0= =0A>[Our pumps come with the lowest of three fixed TRVvalues.=C2=A0 The set= -point is 2,500 psi, thus the statement "approximately 100-140 bar (1500-20= 00 psi) above the system relief valve pressure" still holds true.]=0A>=C2= =A0=0A>I see two interpretations.=0A>=C2=A0=0A>1=E2=80=A6 The TRV =E2=80=9C= setpoint is 2,500 psi=E2=80=9D, presumably referenced to reservoir pressure= , which is ambient cabin pressure assuming the reservoir is well vented. Th= us the TRV will limit the output pressure to 2,500 psig max. In that case t= he graphs in the brochure do not apply for our pumps above 2500 psi.=0A>=C2= =A0=0A>2=E2=80=A6 The TRV setpoint is=E2=80=9C(1500-2000 psi) above the sys= tem relief valve pressure.=E2=80=9D I interpret =E2=80=9Csystem relief valv= e pressure=E2=80=9D to be the setpoint of the internal HPRV or LPRV located= upstream of the check valves. These set points are not specified in the br= ochure, but the performance graphs indicate that the HPRV is at least 3,000= psi which would make the TRV setpoint 4,500 - 5,000 psig.=0A>=C2=A0=0A>Per= haps you are saying the TRV setpoint is 1,500 =E2=80=93 2,000 psi above the= pressure switch setpoint=E2=80=99s, but I was commenting on this quote fro= m the brochure which says something else.=0A>=C2=A0=0A>=E2=80=9CIt is a fix= ed relief valve with a pressure setting approximately 100-140 bar (1500-200= 0 psi) above the system relief valve pressure.=E2=80=9D=0A>=C2=A0=0A>If the= TRV setpoint is lower than the HPRV and LPRV setpoints I see no need for t= he HPRV and LPRV. What is their purpose?=0A>=C2=A0=0A>=C2=A0=0A>I would lik= e to know how much pressure it takes to keep the wheels in the wells during= a high speed high G pullup. If the relief valve lifts and the gear comes o= ut of the wells, it could literally blow the doors off the airplane. If any= body with gauges does a gear test in the next few months, please note the p= ressure just before the gear tightens up in the wells and let me know. Five= times that number should be about right.=0A>Regards,=0A>Bill Hannahan=0A>= =0A ---564810535-920033383-1328326579=:86112 Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: quoted-printable
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Chris, you said, =E2= =80=9C Pressure switch setting <=0Aadjustable relief valve set= ting < thermal relief valve setting=E2=80=9D
=0A=0A 
=0A=0A<= div class=3D"MsoNormal">What is the =E2=80=9Cadjustable re= lief valve setting=E2=80=9D in psi?

How is=0Ait adjusted?
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Regards,
Bill Hannahan

From: Chris Zavatson <chris_zavatson@yahoo.= com>
To: lml@lancai= ronline.net
Sent: Fri= day, February 3, 2012 11:10 AM
Su= bject: [LML] Re: 320/360 Hydraulic Pressure Switch
 <= /div>
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Bill,
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The TRV is selected based on system = operating pressures and not pump capabilities.  It is there to protect= your cylinders and lines and a= nything else downstream of the poppet valves in case of excessive = ;thermal heating.  If we ran our systems at higher pressures, we = would need a different TRV.
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 Pressure switch settin= g < adjustable relief valve setting < thermal relief valve = setting
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Chris Zavats= on
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N91CZ
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360sd
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On Feb 3, 2= 012, at 5:02 AM, Bill Hannahan <wfhan= nahan@yahoo.com> wrote:
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Chris, thanks for the feedback and the work you d= id.
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 =
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I sense a contradiction= in this statement;
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[Our pu= mps come with the lowest of three fixed TRV values.  The set-point is 2,500 psi, thus the stateme= nt "approximately 100-140 bar (1500-2000 psi) abo= ve the system relief valve pressure" still holds true.]=
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=0A<= div class=3D"yiv788248172MsoNormal">I see two interpretations.=
=0A
 
=0A<= div class=3D"yiv788248172MsoNormal">1=E2=80=A6 The TRV =E2=80=9Csetpoint is 2= ,500 psi=E2=80=9D, presumably referenced to reservoir pressure, which is am= bient cabin pressure assuming the reservoir is well vented. Thus the TRV will li= mit the output pressure to 2,500 psig max. In that case the graphs in the broch= ure do not apply for our pumps above 2500 psi.
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2=E2=80=A6 The TRV setpoint is =E2=80=9C(1500-2000 psi) above the system relief valve pressure.=E2=80=9D I inter= pret =E2=80=9Csystem relief valve pressure=E2=80=9D to be the setpoint of the i= nternal HPR= V or LPRV located upstream of the check valves. These set points are not= specified in the brochure, but the performance graphs indicate that the HPRV i= s at least 3,000 psi which would make the TRV setpoint 4,500 - 5,000 psig.
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Perhaps you are saying the TRV setpoint is 1,500 = =E2=80=93 2,000 psi above the pressure switch setpoint=E2=80=99s, but I was com= menting on this quote from the brochure which says something else.=0A
 
=0A=E2=80=9CIt is a fixed relief valve= with a pressure setting approximately 100-140 bar (1500-2000 psi) above th= e system relief valve pressure.=E2=80=9D
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If the TRV= set= point is lower than the HPRV and LPRV setpoints I see no need for the HPRV and LPRV. W= hat is their purpose?
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 =0A
I would like to know how much pres= sure it takes to keep the wheels in the wells during a high speed high G pullup= . If the relief valve lifts and the gear comes out of the wells, it could l= iterally blow the doors off the airplane. If anybody with gauges does a gear te= st in the next few months, please note the pressure just before the gear ti= ghtens up in the wells and let me know. Five times that number should be ab= out right.
=0A
Regards,
Bill Hannahan

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