X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Tue, 31 Jan 2012 11:52:07 -0500 Message-ID: X-Original-Return-Path: Received: from hrndva-omtalb.mail.rr.com ([71.74.56.123] verified) by logan.com (CommuniGate Pro SMTP 5.4.3) with ESMTP id 5371498 for lml@lancaironline.net; Tue, 31 Jan 2012 10:42:54 -0500 Received-SPF: none receiver=logan.com; client-ip=71.74.56.123; envelope-from=Wolfgang@MiCom.net X-Original-Return-Path: X-Authority-Analysis: v=2.0 cv=MaXuSuDf c=1 sm=0 a=MHZY6FYWMEQOp7S43i2QIw==:17 a=ttCsPuSJ-FAA:10 a=Ia-xEzejAAAA:8 a=5FIZSGrRAAAA:8 a=CjxXgO3LAAAA:8 a=XXu8XmDjAAAA:8 a=9mhJpauDnliTKOWJ4ZgA:9 a=ZO_HsIX5d07ZS2swNaAA:7 a=QEXdDO2ut3YA:10 a=CVU0O5Kb7MsA:10 a=wR8WdYEwGqoA:10 a=EzXvWhQp4_cA:10 a=rC2wZJ5BpNYA:10 a=Whv8HLVs5OMA:10 a=aFG-YSNyUVIzumuHwiwA:9 a=48C_7OeGu95Yk6f5GgUA:7 a=RA4776fQhdsA:10 a=MHZY6FYWMEQOp7S43i2QIw==:117 X-Cloudmark-Score: 0 X-Originating-IP: 74.218.201.50 Received: from [74.218.201.50] ([74.218.201.50:1251] helo=lobo) by hrndva-oedge02.mail.rr.com (envelope-from ) (ecelerity 2.2.3.46 r()) with ESMTP id 50/8E-05484-DDB082F4; Tue, 31 Jan 2012 15:42:21 +0000 X-Original-Message-ID: <007101cce02e$e9b20fe0$6701a8c0@lobo> From: "Wolfgang" X-Original-To: References: Subject: Re: [LML] Re: Hydraulic hoses X-Original-Date: Tue, 31 Jan 2012 10:42:17 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_006E_01CCE005.00A9FB60" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.2180 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2180 This is a multi-part message in MIME format. ------=_NextPart_000_006E_01CCE005.00A9FB60 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable From the Oildyne 108 spec sheet, Thermal Relief Valves? - Why? The thermal relief valve?s (TRV) purpose is to allow a bleed off of built up pressure due to thermal expansion of the fluid or to act as a (limited) shock load protection, should a cylinder in the system get bumped. The thermal relief valve is included in circuits using a pilot operated check valve. The single direction units get one; the reversing units get two. It is located between the check valve and the 108 Series pump outlet port. It is a fixed relief valve with a pressure setting approximately 100-140 bar (1500-2000 psi) above the system relief valve pressure. Wolfgang ----- Original Message -----=20 From: Chris Zavatston=20 To: lml@lancaironline.net=20 Sent: Monday, January 30, 2012 8:51 PM Subject: Re: [LML] Re: Hydraulic hoses To follow-up: Our thermal pressure relief valve is nominally 2,500 = psi. It will open somewhere between 2,500 to 2,900 psi. Chris Zavatson N91CZ 360std www.N91CZ.net On Jan 30, 2012, at 9:21 AM, Chris Zavatson = wrote: Lorn, et al Rob is referring to the system downstream of the poppet valve. It = is true that the pump and the adjustable relief valve will not allow the = system to actively pressurize beyond the the relief valve setting. = However once shut down, thermal heating can further raise the pressure = level on the aircraft side. There is a fixed thermal relief valve in = the pump downstream of the poppet valve for just such a reason. I do = not know what its setting is. It is definitely greater that 2,000 psi. = Given that the Oildyne pumps are rated to 3,000, I would not be = surprised if the thermal relief valve rating is greater than 3,000 psi. Chris Zavatson N91CZ 360std www.N91CZ.net From: Lorn H Olsen To: lml@lancaironline.net=20 Sent: Monday, January 30, 2012 7:52 AM Subject: [LML] Re: Hydraulic hoses Rob, If the hydraulic pump is working correctly, it has a 1,400 to 1,500 = PSI override. The pressure in both the up and down side will never be = greater than the override PSI. Lorn > From: "Stevens Family" > Date: January 29, 2012 5:16:11 PM EST >=20 > A quick query from ?Down Under?. I am up to building the hydraulic = system for my Lancair 360, and need to purchase some hydraulic hose for = the gear retract system. I understand the system theoretically operates = at about 1500 PSI. However I have spoken to someone with experience on a = similar aircraft, and he said that he has observed pressures over 2000 = PSI, due to the heat soak phenomenon previously discussed on the LML. >=20 > My question is, what pressure hose have others used in their = aircraft? Do you have any suggestions or useful comments about building = this system? >=20 > Thanks in anticipation. >=20 > Rob Stevens > Perth, Western Australia. -- For archives and unsub = http://mail.lancaironline.net:81/lists/lml/List.html ------=_NextPart_000_006E_01CCE005.00A9FB60 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable =EF=BB=BF
From the Oildyne 108 spec = sheet,

Thermal Relief Valves? - Why?

The thermal relief valve?s (TRV) purpose is to allow = a
bleed=20 off of built up pressure due to thermal expansion
of the fluid or to = act as a=20 (limited) shock load protection,
should a cylinder in the system get=20 bumped.
The thermal relief valve is included in circuits using
a = pilot=20 operated check valve. The single direction
units get one; the = reversing units=20 get two. It is located
between the check valve and the 108 Series=20 pump
outlet port. It is a fixed relief valve with a = pressure
setting=20 approximately 100-140 bar (1500-2000 psi)
above the system relief = valve=20 pressure.

 

Wolfgang

----- Original Message -----
From:=20 Chris=20 Zavatston
Sent: Monday, January 30, 2012 = 8:51=20 PM
Subject: Re: [LML] Re: = Hydraulic=20 hoses

To follow-up:  Our thermal pressure relief valve is = nominally 2,500=20 psi.  It will open somewhere between 2,500 to 2,900 psi.

Chris Zavatson
N91CZ
360std

On Jan 30, 2012, at 9:21 AM, Chris Zavatson <chris_zavatson@yahoo.com>= =20 wrote:

Lorn, et = al
Rob is = referring to the=20 system downstream of the poppet valve.  It is true that the = pump and=20 the adjustable relief valve will not allow the system to actively = pressurize=20 beyond the the relief valve setting.  However once shut down, = thermal=20 heating can further raise the pressure level on the aircraft = side. =20 There is a fixed thermal relief valve in the pump downstream of = the=20 poppet valve for just such a reason.  I do not know what its = setting=20 is.  It is definitely greater that 2,000 psi.  Given that = the=20 Oildyne pumps are rated to 3,000, I would not be surprised if the = thermal=20 relief valve rating is greater than 3,000 psi.
 
Chris Zavatson
N91CZ
360std
www.N91CZ.net
 
 
 
From: Lorn H Olsen <lorn@dynacomm.us>
To: lml@lancaironline.net =
Sent: Monday, January 30, = 2012 7:52=20 AM
Subject: [LML] = Re:=20 Hydraulic hoses

Rob,

If the hydraulic = pump is=20 working correctly, it has a 1,400 to 1,500 PSI override. The = pressure in=20 both the up and down side will never be greater than the override=20 PSI.

Lorn

> From: "Stevens Family" <stevens5@swiftdsl.com.au&= gt;
>=20 Date: January 29, 2012 5:16:11 PM EST
>
> A quick query = from=20 ?Down Under?. I am up to building the hydraulic system for my = Lancair 360,=20 and need to purchase some hydraulic hose for the gear retract = system. I=20 understand the system theoretically operates at about 1500 PSI. = However I=20 have spoken to someone with experience on a similar aircraft, and he = said=20 that he has observed pressures over 2000 PSI, due to the heat soak=20 phenomenon previously discussed on the LML.
>
> My = question is,=20 what pressure hose have others used in their aircraft? Do you have = any=20 suggestions or useful comments about building this system?
> =
>=20 Thanks in anticipation.
>
> Rob Stevens
> Perth, = Western=20 Australia.

--
For archives and unsub http://mail= .lancaironline.net:81/lists/lml/List.html


------=_NextPart_000_006E_01CCE005.00A9FB60--