That's OK if the system being cleaned is not for cryogenics like LOx
because there may be some trapped moisture somewhere in the system like a
valve which would freeze solid. Anhydrous alcohol will scavenge that, then
a dry gas purge.
There are many ways to clean any system just depending on many variables.
A complete disassembly is the best way for a 'one size fits all' approach.
In the old days a vapor degreaser was the gold standard for LOx cleaning.
Same process used in the semiconductor industry. In the late 90's vapor
degreasers could be purchased cheap because of stricter air
pollution regulations mainly in California where Silicon Valley is located.
A $20K degreaser could be bought nearly new for a few $100. And I digress.
Ken
On Sun, Oct 17, 2021 at 10:13 PM Troy Prideaux <troy@xxxxxxxxxxxxxxxxxxxxx>
wrote:
Maybe consider part of a CIP (Clean In Place) process. Something like 5%
solution of caustic (sodium hydroxide) heated to 70-80ish deg C if I
vaguely recall. Pass a given volume through then rinse with a given volume
of clean water. The process is amazingly effective in cleaning out organic
residuals in stainless steel food production lines although there are
probably more steps to it in a large scale industrial plant.
Troy
*From:* arocket-bounce@xxxxxxxxxxxxx [mailto:arocket-bounce@xxxxxxxxxxxxx]
*On Behalf Of *roxanna Mason
*Sent:* Monday, 18 October 2021 2:51 PM
*To:* arocket@xxxxxxxxxxxxx
*Subject:* [AR] Re: Equipment Cleaning Advice
Maybe a hair dryer for high volume low pressure use with an optional heat
mode.
My dad had a belt driven diaphragm compressor for his underwater breathing
system for his gold dredge
An UBA, that's SCUBA w/o the Self Containment feature. ~ 100 psi, plenty
for blowing out flex and rigid lines.
Ken
On Sun, Oct 17, 2021 at 6:16 PM Evan Daniel <evanbd@xxxxxxxxx> wrote:
For oil-free compressors, I like California Air Tools a bunch. Quiet,
long rated life (I haven't really tested this personally), oil-free.
Their models with air dryers are a bit pricey. You can probably get
close enough for most purposes by having a decent water separator
before your regulator and regulating down a good bit from the tank
pressure. (Corollary: don't keep running the blowoff gun while the air
compressor is struggling to keep up with the pressure drooping.)
If you want to spend way too much money on this process, as usual
McMaster has you covered:
https://www.mcmaster.com/blowguns/air-powered-tube-cleaners/
Evan Daniel
On Sun, Oct 17, 2021 at 1:11 PM Rick Wills <willsrw@xxxxxxxxx> wrote:
through the tube. I'll experiment with the approach.
Evan
Thank you for the suggestions. I like the process of drawing a wipe
not smell it any more. I used a needle valve and a N2 bottle to blow dry,
I ended up using IPA through the tube twice and blowing until I could
only used 300 psi of bottle pressure (1000 to 700).
but I could build up a functional system with an appropriate filter. An
The clean filtered blow gun is an interesting idea. A bit pricy at $1000
air pump with filters in series could be done fairly easily.
Behalf Of Evan Daniel
Thanks again & Be Safe,
Rick Wills
Huber Heights, Ohio
-----Original Message-----
From: arocket-bounce@xxxxxxxxxxxxx <arocket-bounce@xxxxxxxxxxxxx> On
Sent: Sunday, 17 October, 2021 11:17 AMon the DI water, but either approach is fine. Washing three times with soap
To: arocket@xxxxxxxxxxxxx
Subject: [AR] Re: Equipment Cleaning Advice
That's the right basic idea. I tend to lean harder on the IPA and less
and water seems excessive; I'd replace that step with something like "clean
as appropriate (technician discretion), visually inspect for no significant
dirt or oil or debris".
let it air dry. This will help remove any dissolved oils that may be in
After the final alcohol clean, I would blow off the alcohol, not just
your IPA, rather than letting them redeposit on the part.
the hose should be relatively clean, and you're mostly worried about minor
For the hose, it will depend a bit on what you're trying to remove. If
dust and handling contamination, I'd flush with IPA, blow dry, maybe repeat
that, then blow some wadded up Kim Wipes or similar through in both
directions until they come out looking clean. Then flush with IPA and
nitrogen twice to ensure the Kim Wipe debris is entirely gone, then blow
off with nitrogen until it doesn't smell.
oil-free compressor with an air dryer if you want. Your blowoff gun will
In all this, you can replace the nitrogen with clean dry air from an
ideally have a final filter on it, such as
https://www.mcmaster.com/blowguns/clean-air-blowguns-6/.
hose I’m cleaning is a used to transfer liquid N2O from a large bottle to a
Evan Daniel
On Fri, Oct 8, 2021 at 9:26 AM <willsrw@xxxxxxxxx> wrote:
Hi
I am looking for a bit of advice on cleaning for a hose for N2O. The
much smaller one.
core. Tube ID is 0.25 inch. End fittings female 37 degree flare, ¼ inch
The hose is 10 feet long, stainless steel braid wrapping over a PTFE
(I think it’s a -4).
oxidizer equipment. Start with mechanical cleaning, three times with soap
With a smaller 12 inch tube I used the same process for cleaning other
and hot water with tap water. Last wash, it was raised thoroughly. Then,
I place the part in an ultrasonic cleaner for 30 minutes at 80 deg C, using
Blue Gold Cleaner and deionized water. Afterwards, it goes into a hot
raise bath. Raise water is distilled water. Next is another distilled
water hot raise bath; then, a cold raise bath. Finally, the part is soaked
in a bath of 100% isopropyl alcohol. Part is removed an let dry. Dries
until I can no longer smell the alcohol. After second mechanical cleaning,
nitrite gloves used during all handling. Parts not directly assembled are
double bagged with date.
alcohol in it and vigorously shake. Then drain and blow with bottled
What should I do with a 10 foot hose? One thought is to put isopropyl
nitrogen until you can’t smell it anymore.
Any suggestions will be appreciated.
Thanks,
Rick Wills
Huber Heights, Ohio