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
<mailto: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
<mailto:willsrw@xxxxxxxxx> > wrote:
Evan
Thank you for the suggestions. I like the process of drawing a wipe through
the tube. I'll experiment with the approach.
I ended up using IPA through the tube twice and blowing until I could not
smell it any more. I used a needle valve and a N2 bottle to blow dry, only
used 300 psi of bottle pressure (1000 to 700).
The clean filtered blow gun is an interesting idea. A bit pricy at $1000 but
I could build up a functional system with an appropriate filter. An air pump
with filters in series could be done fairly easily.
Thanks again & Be Safe,
Rick Wills
Huber Heights, Ohio
-----Original Message-----
From: arocket-bounce@xxxxxxxxxxxxx <mailto:arocket-bounce@xxxxxxxxxxxxx>
<arocket-bounce@xxxxxxxxxxxxx <mailto:arocket-bounce@xxxxxxxxxxxxx> > On
Behalf Of Evan Daniel
Sent: Sunday, 17 October, 2021 11:17 AM
To: arocket@xxxxxxxxxxxxx <mailto:arocket@xxxxxxxxxxxxx>
Subject: [AR] Re: Equipment Cleaning Advice
That's the right basic idea. I tend to lean harder on the IPA and less on the
DI water, but either approach is fine. Washing three times with soap 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".
After the final alcohol clean, I would blow off the alcohol, not just let it
air dry. This will help remove any dissolved oils that may be in your IPA,
rather than letting them redeposit on the part.
For the hose, it will depend a bit on what you're trying to remove. If the
hose should be relatively clean, and you're mostly worried about minor 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.
In all this, you can replace the nitrogen with clean dry air from an oil-free
compressor with an air dryer if you want. Your blowoff gun will ideally have
a final filter on it, such as
https://www.mcmaster.com/blowguns/clean-air-blowguns-6/.
Evan Daniel
On Fri, Oct 8, 2021 at 9:26 AM <willsrw@xxxxxxxxx <mailto:willsrw@xxxxxxxxx>
wrote:
Hi
I am looking for a bit of advice on cleaning for a hose for N2O. The hose
I’m cleaning is a used to transfer liquid N2O from a large bottle to a much
smaller one.
The hose is 10 feet long, stainless steel braid wrapping over a PTFE core.
Tube ID is 0.25 inch. End fittings female 37 degree flare, ¼ inch (I think
it’s a -4).
With a smaller 12 inch tube I used the same process for cleaning other
oxidizer equipment. Start with mechanical cleaning, three times with soap
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.
What should I do with a 10 foot hose? One thought is to put isopropyl
alcohol in it and vigorously shake. Then drain and blow with bottled
nitrogen until you can’t smell it anymore.
Any suggestions will be appreciated.
Thanks,
Rick Wills
Huber Heights, Ohio