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View Full Version : how to disassembly the FAV in HFS-3 to clean it up?


softic
11-10-2011, 02:03 PM
my FAV seems to get dirty as it does not open at all times (even during system check with FAV and SYS jumpers 'on'!)
is there any way to disassembly the FAV in HFS-3 to clean it up?

can I unmount the valve body or it is soldered forever?
please, help me... really don't want to spend extra $100 for just diry valve :cry::cry::cry:

Richard L
12-10-2011, 09:14 AM
The FAV should not requirte any cleaning for the duration of itd service life, assuming the high purity of water and methanol is used.

If you have intermittent problems, it will be due to the internal epdm seal being compromised with hydrocarbon or other chemical intentionally, making it swelling up. Always buy seal cans of methanol and Di water.

The FAV cannot be opened up, the only wayt to clean ir is is by soaking it in pure methanol overnight, it might be able to drawn soem of the contaminants out of the seal.

There is a possibility of deris... remove the debris by reverse flow using the TST jumper. Don't it more than 10-20 seconds a time.

softic
16-10-2011, 06:43 PM
Richard, unfortunately soaking in methanol did not help at all and I disassembled the FAV.
Actually I can't agree with statement that FAV cannot be opened up - its body is just glued up with loctite (or similar glue).

After FAV was disassembled I have discovered that for some reason the internal part of valve can't move at all.
So if the bolt on the rear side of FAV is not fully tightened - FAV operates without any issues!

With fully tightened bolt the internal part has no free space to move even if I remove the valve's spring.
What I will do next is loosen a bit (1+1/2 turns) the read bolt and put it on the loctite - should work fine, but not sure is loctite will handle operations with methanol...

I will attach some pictures of my FAV assembly - maybe you could tell me what was wrong with it.
The worst thing for me is that FAV was working fine before and I have no understanding of what could cause problems
(seems like the port in FAV, that is to be closed by valve's internal part was moved a bit).

Richard L
16-10-2011, 11:29 PM
It is not a good idea to disassembe the FAV because the lift of the internal plunger is caliabrated individually due to manfacturing tolerance. Without the proper setup it is impossible to do it properly, flow linearity vs PWM signal cannot be guaranteed.

Did you mark the original position of the end bolt?

Loctitle used on the FAV is recommended by loctitle (company) for methanol compatibility. Most loctile is compatible in any case but we can disclose the type we used as it is a sensirtive infomartion. We have used the same loctile since 2002 and has very liable.

We could have made the top bolt with o-ring seal instes dof loctite seal but vlave specificiations and repeatibility will change over time.

The only time the valve can stick close is the the EPDM runner seat. It is very sensitive to hydrocarbon contamination. It swells up to occupy the gap so no flow can go past.

If you did not find any debris inside the valve, check the EPDM seal. It should be dead flat.

softic
17-10-2011, 06:18 AM
Richard, many thanks for such prompt reply!!
Below are some pictures of valve's internals - the seal seems to be too big (and there were no derbis inside):

http://aklepikov.ru/wp-content/uploads/2011/10/320.jpg
http://aklepikov.ru/wp-content/uploads/2011/10/322.jpg
http://aklepikov.ru/wp-content/uploads/2011/10/312.jpg

Richard L
17-10-2011, 08:48 AM
These are wonderful pictures.

It appeared the epdm seal has been conpromised, There is no way you get any consistancy on flow now. I suggest getting a new fav.

There is a very large flow variation with 0.1mm difference. All the valves are set to be within +/- 0.01mm variation. You need a new spring as well.

Is it possible that you send the FAV back to me and I will do it for you at no charge if you pay the return postage. Is airmail post reliable to Russia?

Can I ask you what mix did you put into your water tank? In the past, if you buy your methanol from a race shop, the transfer pump could be laced with hydrocarbon residues. Always buy from a industrial chemical source in seal containers.

softic
17-10-2011, 03:30 PM
Dear Richard,

The airmail in Russia is quite slow (due to customs, not to slow aircrafts)))
I will have circuit racing event on November 4th and not sure if I will get back the new valve before it (so I have a chance to race without WAI).

Can you please tell me if I will carefully measure flow rate on full flow (I see it is around 380cc/min now) - is it enough to calibrate the system?
And, if at later tame the FAV will fail again I will be glad to use your offer... just don't want to mess the event and test Aquamist in a really heavy conditions (1 hour of non-stop race).

But if there is an option when I pay for return postage giving the old FAV to the delivery service in exchange to the new one (if such offering is available) - I would be glad to order such service!

Anyway, I am very glad to see the way you support Aquamist products - this is how the support service should be!
Hopefully I will be coming back to you only with good news :)
(and please, check the post about restrictors (http://www.aquamist.co.uk/vbulletin/showthread.php?p=15333#post15333) as well, if you will have a free minute)

Regards,
Alexey

Richard L
17-10-2011, 03:46 PM
I will put in a new plunger and reset the correct lift. I am unable able to give you a new valve.

There is nothing to go wrong with the rest. What did you mix into the water tank? The seal shoudl never swell in the correct water/methanol mix.

If I put on the package the valve is a repaired unit and orignated form Russia, would this help speeding up the customs?

Richard

softic
17-10-2011, 07:35 PM
Richard, I'm not sure it this will help much... Russian customs are extremely stupid and greedy (((
Since I have initially ordered two HFS-3 kits (one for my friend) - I will compare my valve with the original one and will send my own for repair if it is really bad.

The mix that caused problems was with additive of valve cleaning fluid.
I thought it is based on spirits only as per ingredients list, but seems like this list it was lying ((((

Today I was driving with fixed valve on pure water and it worked fine!
Tomorrow will do test on 99% methanol and will see if anything is wrong.

The only thing I am really worried about is the problem with non-working restrictors...

Richard L
17-10-2011, 08:01 PM
There is a very good chance your valve will work with a reasonable linearity. Not sure what will happen when the epdm returns to normal height. You will probably see more flow at the middle to high dc range due more lift (relative). The chance of the valve leaking is very low as the spring will take up the lift increase.