Today's Message Index:
----------------------
1. 04:06 AM - Re: pneumatic system woes (Cpayne)
2. 06:17 AM - Re: Re: pneumatic system woes (Byron M Fox)
3. 08:40 AM - Re: pneumatic system woes (Walter Lannon)
4. 09:20 AM - Re: pneumatic system woes (Hank Gibson)
5. 09:42 AM - Re: pneumatic system woes (doug sapp)
6. 09:53 AM - Re: pneumatic system woes (Tom Elliott)
7. 09:54 AM - Re: pneumatic system woes (William Halverson)
8. 10:37 AM - Re: pneumatic system woes (A. Dennis Savarese)
9. 10:48 AM - Re: pneumatic system woes (A. Dennis Savarese)
10. 11:16 AM - Re: pneumatic system woes (William Halverson)
11. 12:19 PM - Re: pneumatic system woes (Elmar & Manuela Hegenauer)
Message 1
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| Subject: | Re: pneumatic system woes |
Check valves seals should last a lot longer. Use high strength, high temp, oil-resistant
synthetic material with about a 60-70 durometer(A) material. Buna-N
grades like Nitrile, silicone rubber or EPDM selected to meet the task. I believe
I stamped mine from weather resistant EPDM.
Craig Payne
Message 2
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| Subject: | Re: pneumatic system woes |
Craig, where did you find an off-the-shelf stamp or punch to make your seals?
Blitz Fox
415-307-2405
On Jan 31, 2013, at 4:03 AM, Cpayne <cpayne@joimail.com> wrote:
>
> Check valves seals should last a lot longer. Use high strength, high temp, oil-resistant
synthetic material with about a 60-70 durometer(A) material. Buna-N
grades like Nitrile, silicone rubber or EPDM selected to meet the task. I believe
I stamped mine from weather resistant EPDM.
>
> Craig Payne
>
>
>
>
Message 3
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| Subject: | Re: pneumatic system woes |
Elmar;
I have been making them from 3/32" neoprene. They don't last forever but
at least a few years. Recently changed to VITON. We'll see how that
stands up.
The material must be a nitrile, not natural, rubber of a fairly high
Durometer reading - about 70 as I recall.
Walt
-----Original Message-----
From: Elmar & Manuela Hegenauer
Sent: Wednesday, January 30, 2013 8:39 PM
Subject: Yak-List: pneumatic system woes
Keith and others,
I usually have my all my check valves
on my CJ overhauled with every annual.
For that purpose I have stocked up springs
and rubber pads but I can't remember the
supplier :-(
To make a long story short, all those rubber
pads I have used over the years have failed
sooner or later between the annuals, so I
got curious.
Now let's get technical, Brian Lloyd are
you still alive?
The rubber pad in a CJ check valve has a
nominal diameter of 13 mm what translates
into a area of circle of roughly 132 square
millimetres or 1.32 square centimetres.
The physical weight introduced to this little
piece of rubber is around 66kgs/145 lbs at
50 bars/700 psi.
That is a lot of pressure on a small rubber disc
going against the sharp and perforated
seat of the lower check valve assembly.
I have done some tests in my workshop at factor
1.5 over a period of several months and the rubber
pads all disintegrated (with and without air tool oil),
the material seems to be too thin and soft!!!
Any constructive thoughts or ideas?
cheers
Elmar
Message 4
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| Subject: | Re: pneumatic system woes |
Can you all share the details of how the proper diameter disc is stamped out; type
of tool, etc?
Thanks- Hoot
Sent from my iPhone
On Jan 31, 2013, at 11:36 AM, "Walter Lannon" <wlannon@shaw.ca> wrote:
>
> Elmar;
>
> I have been making them from 3/32" neoprene. They don't last forever but at
least a few years. Recently changed to VITON. We'll see how that stands up.
>
> The material must be a nitrile, not natural, rubber of a fairly high Durometer
reading - about 70 as I recall.
>
> Walt
>
> -----Original Message----- From: Elmar & Manuela Hegenauer
> Sent: Wednesday, January 30, 2013 8:39 PM
> To: yak-list@matronics.com
> Subject: Yak-List: pneumatic system woes
>
>
> Keith and others,
>
> I usually have my all my check valves
> on my CJ overhauled with every annual.
>
> For that purpose I have stocked up springs
> and rubber pads but I can't remember the
> supplier :-(
>
> To make a long story short, all those rubber
> pads I have used over the years have failed
> sooner or later between the annuals, so I
> got curious.
>
> Now let's get technical, Brian Lloyd are
> you still alive?
>
> The rubber pad in a CJ check valve has a
> nominal diameter of 13 mm what translates
> into a area of circle of roughly 132 square
> millimetres or 1.32 square centimetres.
>
> The physical weight introduced to this little
> piece of rubber is around 66kgs/145 lbs at
> 50 bars/700 psi.
>
> That is a lot of pressure on a small rubber disc
> going against the sharp and perforated
> seat of the lower check valve assembly.
>
> I have done some tests in my workshop at factor
> 1.5 over a period of several months and the rubber
> pads all disintegrated (with and without air tool oil),
> the material seems to be too thin and soft!!!
>
> Any constructive thoughts or ideas?
>
> cheers
>
> Elmar
>
>
>
>
>
>
>
>
Message 5
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| Subject: | Re: pneumatic system woes |
Last week I ordered up a sheet of Viton to try. I'm sure I can easily make
a cutter/stamp on the lathe. If they work I plan to make my own to use in
my $13 overhaul kits. I do agree the life of the Chinese rubber disc seems
to be short. In my opinion several factors are the prime movers in
determining the life of the discs, one is the pressure you have you pop off
valve set at. The Chinese set theirs at exactly 45 ATMS, while many US
aircraft are set at 50 or higher. Second is the use of oils which may be
attacking the rubber (making it softer). The Chinese use only castor oil.
Third would be the stainless steel springs, rust particles and broken
spring parts from the stock (std steel) Chinese often cause check valves
not to seal properly.
Doug
On Thu, Jan 31, 2013 at 9:17 AM, Hank Gibson <hkgibby@yahoo.com> wrote:
>
> Can you all share the details of how the proper diameter disc is stamped
> out; type of tool, etc?
>
> Thanks- Hoot
>
> Sent from my iPhone
>
> On Jan 31, 2013, at 11:36 AM, "Walter Lannon" <wlannon@shaw.ca> wrote:
>
> >
> > Elmar;
> >
> > I have been making them from 3/32" neoprene. They don't last forever
> but at least a few years. Recently changed to VITON. We'll see how that
> stands up.
> >
> > The material must be a nitrile, not natural, rubber of a fairly high
> Durometer reading - about 70 as I recall.
> >
> > Walt
> >
> > -----Original Message----- From: Elmar & Manuela Hegenauer
> > Sent: Wednesday, January 30, 2013 8:39 PM
> > To: yak-list@matronics.com
> > Subject: Yak-List: pneumatic system woes
> >
> samira.h@shaw.ca>
> >
> > Keith and others,
> >
> > I usually have my all my check valves
> > on my CJ overhauled with every annual.
> >
> > For that purpose I have stocked up springs
> > and rubber pads but I can't remember the
> > supplier :-(
> >
> > To make a long story short, all those rubber
> > pads I have used over the years have failed
> > sooner or later between the annuals, so I
> > got curious.
> >
> > Now let's get technical, Brian Lloyd are
> > you still alive?
> >
> > The rubber pad in a CJ check valve has a
> > nominal diameter of 13 mm what translates
> > into a area of circle of roughly 132 square
> > millimetres or 1.32 square centimetres.
> >
> > The physical weight introduced to this little
> > piece of rubber is around 66kgs/145 lbs at
> > 50 bars/700 psi.
> >
> > That is a lot of pressure on a small rubber disc
> > going against the sharp and perforated
> > seat of the lower check valve assembly.
> >
> > I have done some tests in my workshop at factor
> > 1.5 over a period of several months and the rubber
> > pads all disintegrated (with and without air tool oil),
> > the material seems to be too thin and soft!!!
> >
> > Any constructive thoughts or ideas?
> >
> > cheers
> >
> > Elmar
> >
> >
> >
> >
> >
> >
> >
> >
>
>
Message 6
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| Subject: | pneumatic system woes |
The ones I bought from Gary Bunn have been holding up very well. I do
not know what the material is? Some of them have been in place for 5 + years
Tom Elliott
CJ-6A NX63727
777 Quartz Ave
PMB 7004
Sandy Valley NV
89019
Cell 541-297-5497
-----Original Message-----
From: owner-yak-list-server@matronics.com [mailto:owner-yak-list-server@matronics.com] On Behalf Of
Walter Lannon
Sent: Thursday, January 31, 2013 8:37 AM
Subject: Re: Yak-List: pneumatic system woes
Elmar;
I have been making them from 3/32" neoprene. They don't last forever but
at least a few years. Recently changed to VITON. We'll see how that
stands up.
The material must be a nitrile, not natural, rubber of a fairly high Durometer
reading - about 70 as
I recall.
Walt
-----Original Message-----
From: Elmar & Manuela Hegenauer
Sent: Wednesday, January 30, 2013 8:39 PM
Subject: Yak-List: pneumatic system woes
--> <samira.h@shaw.ca>
Keith and others,
I usually have my all my check valves
on my CJ overhauled with every annual.
For that purpose I have stocked up springs and rubber pads but I can't remember
the supplier :-(
To make a long story short, all those rubber pads I have used over the years have
failed sooner or
later between the annuals, so I got curious.
Now let's get technical, Brian Lloyd are you still alive?
The rubber pad in a CJ check valve has a nominal diameter of 13 mm what translates
into a area of
circle of roughly 132 square millimetres or 1.32 square centimetres.
The physical weight introduced to this little piece of rubber is around 66kgs/145
lbs at
50 bars/700 psi.
That is a lot of pressure on a small rubber disc going against the sharp and perforated
seat of the
lower check valve assembly.
I have done some tests in my workshop at factor
1.5 over a period of several months and the rubber pads all disintegrated (with
and without air tool
oil), the material seems to be too thin and soft!!!
Any constructive thoughts or ideas?
cheers
Elmar
much more:
Message 7
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| Subject: | Re: pneumatic system woes |
Are check valves a problem for YAKs?
William
-----Original Message-----
From: doug sapp [mailto:dougsappllc@gmail.com]
Sent: Thursday, January 31, 2013 09:39 AM
Subject: Re: Yak-List: pneumatic system woes
Last week I ordered up a sheet of Viton to try. I'm sure I can easily make
a cutter/stamp on the lathe. If they work I plan to make my own to use in
my $13 overhaul kits. I do agree the life of the Chinese rubber disc seems
to be short. In my opinion several factors are the prime movers in
determining the life of the discs, one is the pressure you have you pop off
valve set at. The Chinese set theirs at exactly 45 ATMS, while many US
aircraft are set at 50 or higher. Second is the use of oils which may be
attacking the rubber (making it softer). The Chinese use only castor oil.
Third would be the stainless steel springs, rust particles and broken
spring parts from the stock (std steel) Chinese often cause check valves
not to seal properly.
Doug
On Thu, Jan 31, 2013 at 9:17 AM, Hank Gibson <hkgibby@yahoo.com> wrote:
>
> Can you all share the details of how the proper diameter disc is stamped
> out; type of tool, etc?
>
> Thanks- Hoot
>
> Sent from my iPhone
>
> On Jan 31, 2013, at 11:36 AM, "Walter Lannon" <wlannon@shaw.ca> wrote:
>
> >
> > Elmar;
> >
> > I have been making them from 3/32" neoprene. They don't last forever
> but at least a few years. Recently changed to VITON. We'll see how that
> stands up.
> >
> > The material must be a nitrile, not natural, rubber of a fairly high
> Durometer reading - about 70 as I recall.
> >
> > Walt
> >
> > -----Original Message----- From: Elmar & Manuela Hegenauer
> > Sent: Wednesday, January 30, 2013 8:39 PM
> > To: yak-list@matronics.com
> > Subject: Yak-List: pneumatic system woes
> >
> samira.h@shaw.ca>
> >
> > Keith and others,
> >
> > I usually have my all my check valves
> > on my CJ overhauled with every annual.
> >
> > For that purpose I have stocked up springs
> > and rubber pads but I can't remember the
> > supplier :-(
> >
> > To make a long story short, all those rubber
> > pads I have used over the years have failed
> > sooner or later between the annuals, so I
> > got curious.
> >
> > Now let's get technical, Brian Lloyd are
> > you still alive?
> >
> > The rubber pad in a CJ check valve has a
> > nominal diameter of 13 mm what translates
> > into a area of circle of roughly 132 square
> > millimetres or 1.32 square centimetres.
> >
> > The physical weight introduced to this little
> > piece of rubber is around 66kgs/145 lbs at
> > 50 bars/700 psi.
> >
> > That is a lot of pressure on a small rubber disc
> > going against the sharp and perforated
> > seat of the lower check valve assembly.
> >
> > I have done some tests in my workshop at factor
> > 1.5 over a period of several months and the rubber
> > pads all disintegrated (with and without air tool oil),
> > the material seems to be too thin and soft!!!
> >
> > Any constructive thoughts or ideas?
> >
> > cheers
> >
> > Elmar
> >
> >
> >
> >
> >
> >
> >
> >
>
>
Message 8
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| Subject: | Re: pneumatic system woes |
The check valves in the Yak 52 are totally different internally than the
ones in the CJ. They also have a rubber seal on the end of a piston.
The sealing surface does not a sharp edge. The rubber seal on the
piston presses up against a smooth, rounded edge surface.
Denni
A. Dennis Savarese
334-285-6263
334-546-8182 (mobile)
www.yak-52.com
Skype - Yakguy1
On 1/31/2013 11:52 AM, William Halverson wrote:
>
>
> Are check valves a problem for YAKs?
>
> William
>
> -----Original Message-----
> From: doug sapp [mailto:dougsappllc@gmail.com]
> Sent: Thursday, January 31, 2013 09:39 AM
> To: yak-list@matronics.com
> Subject: Re: Yak-List: pneumatic system woes
>
> Last week I ordered up a sheet of Viton to try. I'm sure I can easily make
> a cutter/stamp on the lathe. If they work I plan to make my own to use in
> my $13 overhaul kits. I do agree the life of the Chinese rubber disc seems
> to be short. In my opinion several factors are the prime movers in
> determining the life of the discs, one is the pressure you have you pop off
> valve set at. The Chinese set theirs at exactly 45 ATMS, while many US
> aircraft are set at 50 or higher. Second is the use of oils which may be
> attacking the rubber (making it softer). The Chinese use only castor oil.
> Third would be the stainless steel springs, rust particles and broken
> spring parts from the stock (std steel) Chinese often cause check valves
> not to seal properly.
>
> Doug
>
> On Thu, Jan 31, 2013 at 9:17 AM, Hank Gibson <hkgibby@yahoo.com> wrote:
>
>>
>> Can you all share the details of how the proper diameter disc is stamped
>> out; type of tool, etc?
>>
>> Thanks- Hoot
>>
>> Sent from my iPhone
>>
>> On Jan 31, 2013, at 11:36 AM, "Walter Lannon" <wlannon@shaw.ca> wrote:
>>
>>>
>>> Elmar;
>>>
>>> I have been making them from 3/32" neoprene. They don't last forever
>> but at least a few years. Recently changed to VITON. We'll see how that
>> stands up.
>>> The material must be a nitrile, not natural, rubber of a fairly high
>> Durometer reading - about 70 as I recall.
>>> Walt
>>>
>>> -----Original Message----- From: Elmar & Manuela Hegenauer
>>> Sent: Wednesday, January 30, 2013 8:39 PM
>>> To: yak-list@matronics.com
>>> Subject: Yak-List: pneumatic system woes
>>>
>> samira.h@shaw.ca>
>>> Keith and others,
>>>
>>> I usually have my all my check valves
>>> on my CJ overhauled with every annual.
>>>
>>> For that purpose I have stocked up springs
>>> and rubber pads but I can't remember the
>>> supplier :-(
>>>
>>> To make a long story short, all those rubber
>>> pads I have used over the years have failed
>>> sooner or later between the annuals, so I
>>> got curious.
>>>
>>> Now let's get technical, Brian Lloyd are
>>> you still alive?
>>>
>>> The rubber pad in a CJ check valve has a
>>> nominal diameter of 13 mm what translates
>>> into a area of circle of roughly 132 square
>>> millimetres or 1.32 square centimetres.
>>>
>>> The physical weight introduced to this little
>>> piece of rubber is around 66kgs/145 lbs at
>>> 50 bars/700 psi.
>>>
>>> That is a lot of pressure on a small rubber disc
>>> going against the sharp and perforated
>>> seat of the lower check valve assembly.
>>>
>>> I have done some tests in my workshop at factor
>>> 1.5 over a period of several months and the rubber
>>> pads all disintegrated (with and without air tool oil),
>>> the material seems to be too thin and soft!!!
>>>
>>> Any constructive thoughts or ideas?
>>>
>>> cheers
>>>
>>> Elmar
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>
>>
>>
>>
>>
>
>
Message 9
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| Subject: | Re: pneumatic system woes |
I meant, "does not HAVE a sharp edge. Sorry.
Dennis
A. Dennis Savarese
334-285-6263
334-546-8182 (mobile)
www.yak-52.com
Skype - Yakguy1
On 1/31/2013 12:35 PM, A. Dennis Savarese wrote:
> <dsavarese0812@bellsouth.net>
>
> The check valves in the Yak 52 are totally different internally than
> the ones in the CJ. They also have a rubber seal on the end of a
> piston. The sealing surface does not a sharp edge. The rubber seal
> on the piston presses up against a smooth, rounded edge surface.
> Denni
>
> A. Dennis Savarese
> 334-285-6263
> 334-546-8182 (mobile)
> www.yak-52.com
> Skype - Yakguy1
>
> On 1/31/2013 11:52 AM, William Halverson wrote:
>> <william@netpros.net>
>>
>>
>> Are check valves a problem for YAKs?
>>
>> William
>>
>> -----Original Message-----
>> From: doug sapp [mailto:dougsappllc@gmail.com]
>> Sent: Thursday, January 31, 2013 09:39 AM
>> To: yak-list@matronics.com
>> Subject: Re: Yak-List: pneumatic system woes
>>
>> Last week I ordered up a sheet of Viton to try. I'm sure I can easily
>> make
>> a cutter/stamp on the lathe. If they work I plan to make my own to
>> use in
>> my $13 overhaul kits. I do agree the life of the Chinese rubber disc
>> seems
>> to be short. In my opinion several factors are the prime movers in
>> determining the life of the discs, one is the pressure you have you
>> pop off
>> valve set at. The Chinese set theirs at exactly 45 ATMS, while many US
>> aircraft are set at 50 or higher. Second is the use of oils which
>> may be
>> attacking the rubber (making it softer). The Chinese use only castor
>> oil.
>> Third would be the stainless steel springs, rust particles and broken
>> spring parts from the stock (std steel) Chinese often cause check valves
>> not to seal properly.
>>
>> Doug
>>
>> On Thu, Jan 31, 2013 at 9:17 AM, Hank Gibson <hkgibby@yahoo.com> wrote:
>>
>>>
>>> Can you all share the details of how the proper diameter disc is
>>> stamped
>>> out; type of tool, etc?
>>>
>>> Thanks- Hoot
>>>
>>> Sent from my iPhone
>>>
>>> On Jan 31, 2013, at 11:36 AM, "Walter Lannon" <wlannon@shaw.ca> wrote:
>>>
>>>>
>>>> Elmar;
>>>>
>>>> I have been making them from 3/32" neoprene. They don't last forever
>>> but at least a few years. Recently changed to VITON. We'll see
>>> how that
>>> stands up.
>>>> The material must be a nitrile, not natural, rubber of a fairly high
>>> Durometer reading - about 70 as I recall.
>>>> Walt
>>>>
>>>> -----Original Message----- From: Elmar & Manuela Hegenauer
>>>> Sent: Wednesday, January 30, 2013 8:39 PM
>>>> To: yak-list@matronics.com
>>>> Subject: Yak-List: pneumatic system woes
>>>>
>>> samira.h@shaw.ca>
>>>> Keith and others,
>>>>
>>>> I usually have my all my check valves
>>>> on my CJ overhauled with every annual.
>>>>
>>>> For that purpose I have stocked up springs
>>>> and rubber pads but I can't remember the
>>>> supplier :-(
>>>>
>>>> To make a long story short, all those rubber
>>>> pads I have used over the years have failed
>>>> sooner or later between the annuals, so I
>>>> got curious.
>>>>
>>>> Now let's get technical, Brian Lloyd are
>>>> you still alive?
>>>>
>>>> The rubber pad in a CJ check valve has a
>>>> nominal diameter of 13 mm what translates
>>>> into a area of circle of roughly 132 square
>>>> millimetres or 1.32 square centimetres.
>>>>
>>>> The physical weight introduced to this little
>>>> piece of rubber is around 66kgs/145 lbs at
>>>> 50 bars/700 psi.
>>>>
>>>> That is a lot of pressure on a small rubber disc
>>>> going against the sharp and perforated
>>>> seat of the lower check valve assembly.
>>>>
>>>> I have done some tests in my workshop at factor
>>>> 1.5 over a period of several months and the rubber
>>>> pads all disintegrated (with and without air tool oil),
>>>> the material seems to be too thin and soft!!!
>>>>
>>>> Any constructive thoughts or ideas?
>>>>
>>>> cheers
>>>>
>>>> Elmar
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>
>>>
>>>
>>>
>>>
>>
>>
>>
>>
>>
>>
>>
>
>
Message 10
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| Subject: | Re: pneumatic system woes |
OK thanks!
-----Original Message-----
From: A. Dennis Savarese [mailto:dsavarese0812@bellsouth.net]
Sent: Thursday, January 31, 2013 10:35 AM
Subject: Re: Yak-List: pneumatic system woes
The check valves in the Yak 52 are totally different internally than the
ones in the CJ. They also have a rubber seal on the end of a piston.
The sealing surface does not a sharp edge. The rubber seal on the
piston presses up against a smooth, rounded edge surface.
Denni
A. Dennis Savarese
334-285-6263
334-546-8182 (mobile)
www.yak-52.com
Skype - Yakguy1
On 1/31/2013 11:52 AM, William Halverson wrote:
>
>
> Are check valves a problem for YAKs?
>
> William
>
> -----Original Message-----
> From: doug sapp [mailto:dougsappllc@gmail.com]
> Sent: Thursday, January 31, 2013 09:39 AM
> To: yak-list@matronics.com
> Subject: Re: Yak-List: pneumatic system woes
>
> Last week I ordered up a sheet of Viton to try. I'm sure I can easily make
> a cutter/stamp on the lathe. If they work I plan to make my own to use in
> my $13 overhaul kits. I do agree the life of the Chinese rubber disc seems
> to be short. In my opinion several factors are the prime movers in
> determining the life of the discs, one is the pressure you have you pop off
> valve set at. The Chinese set theirs at exactly 45 ATMS, while many US
> aircraft are set at 50 or higher. Second is the use of oils which may be
> attacking the rubber (making it softer). The Chinese use only castor oil.
> Third would be the stainless steel springs, rust particles and broken
> spring parts from the stock (std steel) Chinese often cause check valves
> not to seal properly.
>
> Doug
>
> On Thu, Jan 31, 2013 at 9:17 AM, Hank Gibson <hkgibby@yahoo.com> wrote:
>
>>
>> Can you all share the details of how the proper diameter disc is stamped
>> out; type of tool, etc?
>>
>> Thanks- Hoot
>>
>> Sent from my iPhone
>>
>> On Jan 31, 2013, at 11:36 AM, "Walter Lannon" <wlannon@shaw.ca> wrote:
>>
>>>
>>> Elmar;
>>>
>>> I have been making them from 3/32" neoprene. They don't last forever
>> but at least a few years. Recently changed to VITON. We'll see how that
>> stands up.
>>> The material must be a nitrile, not natural, rubber of a fairly high
>> Durometer reading - about 70 as I recall.
>>> Walt
>>>
>>> -----Original Message----- From: Elmar & Manuela Hegenauer
>>> Sent: Wednesday, January 30, 2013 8:39 PM
>>> To: yak-list@matronics.com
>>> Subject: Yak-List: pneumatic system woes
>>>
>> samira.h@shaw.ca>
>>> Keith and others,
>>>
>>> I usually have my all my check valves
>>> on my CJ overhauled with every annual.
>>>
>>> For that purpose I have stocked up springs
>>> and rubber pads but I can't remember the
>>> supplier :-(
>>>
>>> To make a long story short, all those rubber
>>> pads I have used over the years have failed
>>> sooner or later between the annuals, so I
>>> got curious.
>>>
>>> Now let's get technical, Brian Lloyd are
>>> you still alive?
>>>
>>> The rubber pad in a CJ check valve has a
>>> nominal diameter of 13 mm what translates
>>> into a area of circle of roughly 132 square
>>> millimetres or 1.32 square centimetres.
>>>
>>> The physical weight introduced to this little
>>> piece of rubber is around 66kgs/145 lbs at
>>> 50 bars/700 psi.
>>>
>>> That is a lot of pressure on a small rubber disc
>>> going against the sharp and perforated
>>> seat of the lower check valve assembly.
>>>
>>> I have done some tests in my workshop at factor
>>> 1.5 over a period of several months and the rubber
>>> pads all disintegrated (with and without air tool oil),
>>> the material seems to be too thin and soft!!!
>>>
>>> Any constructive thoughts or ideas?
>>>
>>> cheers
>>>
>>> Elmar
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>
>>
>>
>>
>>
>
>
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| Subject: | RE: pneumatic system woes |
Hi again,
I would like to thank everybody for
their input and possible solutions.
I will follow the one or other advice
and will do some tests again over
a period of several months before
I introduce the new material to my
aircraft.
Thank you again.
cheers
Elmar
P.S.: Dennis is right, I have one
YAK 52 check valve in my CJ and
it works for 16 years without any
problems.
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