Need to make a suction (siphon) pump

[middle.road]

Let me start the new year off with possibly a very stupid question.

If possible I'm attempting to make up a siphon pump to use in a medical application for use at home.
Trying to curb medical costs here wherever I can.

Can I take a 2.5 or 3.5CFM vacuum pump from HF or Amazon and make up a medical use siphon pump?
I have (3) sets of hoses and collection canisters to put to use.

Insurance out-of-pocket resets Sunday and the charges for this pump are rather outrageous.
I tried talking to the medical supply company Thursday to get a fix on costs but all I was able to
get out of them is that after a year I'll own it. Which appears to be ~$86.00 per month x 12 = $1032 for a device that retails for $250.00
No Straight answer.

I am currently using one mfg'd by 'Drive Medical' Model 18600 it looks pretty much like the ones at HF and Amazon except it's oilless.
Maximum Vacuum 560 +/- 3% mmHg (56 cmHg +/- 3%)
Flow Range > 40 LPM
I have no idea what mmHg or cmHg is, and my cognitive skills are not doing too well these days.
I'm not doing well and am having a hard time trying to match up the spec numbers.

I was thinking of maybe this one from Amazon : -=- LINK -=-
Or this one from Harbor Freight : -=- LINK -=-

Only other item I believe I would need to get is a quality vacuum regulator. The one on the 'Drive' unit is not very good.

_Dan

 

[RJSakowski]

The 560 mm Hg refers to the height of a column of mercury that the pump can lift. Atmospheric pressure is approximately 30" or 760 mm Hg and a perfect vacuum would be able to lift a column of mercury that high. The pump you link pumps to about 74% of a perfect vacuum. Vacuum pumps are often rated in the pressure above a perfect vacuum, also in mm Hg or microns Hg. This is used for high vacuum pumps as previous specification doesn't mean much at those levels of vacuum. This can be confusing as one has to know which measurement they are using.

The two pumps that you are considering are capable of a much higher vacuum than the one you want to replace. Without knowing what the intended use is, I would expect that in order to substitute a different pump, you will also need a vacuum regulator. More than likely the medical pump has one built in as most pumps are capable of around 25" or 630mm HG.

One thing to realize is that the medical pump is a medical device and as such is highly regulated by the FDA (why it costs so much). The HF and Amazon pumps definitely are not.. For personal use, I don't know if this matters much but there may be some ramifications. Also, the pump that you linked to has some auxiliary equipment that would have to be replicated. All things considered, you can probably make a DIY replicate system.

A vacuum regulator can be obtained from McMaster Carr. I used this one: https://www.mcmaster.com/41585K43 However, be aware that they are intended for evacuating relatively clean air. Moisture and/or biowaste can shorten their effective life.

 

[JimDawson]

Here's one that is a bit closer in spec than a high vacuum pump. https://www.amazon.com/Portable-Com...ix=vacuum+pump+air+compressor,aps,140&sr=8-13

These are diaphragm pumps, rather than rotary like the high vacuum pumps are. I think a single cylinder pump like the one linked to above would meet the exact spec. Gast makes one, but it would be in the $500 range.

 

[Ulma Doctor]

Hi Dan,
I have access to some small capacity vacuum pumps, around 22”Hg.
Similar to the Gast pump
I can donate one for experimentation.
They are single stage diaphragm pumps. They have stainless steel valves, made for food service machines.
They run on 115vac, approximately 4 amps draw . Quiet operation.

 

[ddillman]

one draw back of the HF pump is they are very noisy

 

[JimDawson]

one draw back of the HF pump is they are very noisy

And create a major oil fog at low vacuum/high flow rates. I use one for a vacuum chuck on my mill.

 

[homebrewed]

Most vacuum pumps don't like getting fluid into them so that might be an issue regarding the adaptation of an A/C style vacuum pump. A possible alternative, and one that is cheap, easy to clean and forgiving with regard to liquids getting into it is an aspirator. Their ultimate vacuum limit is around the vapor pressure of the water used to pull the vacuum so you probably wouldn't be see much, if any, reduction in performance compared to a mechanical pump.

That said, of course you need a source of pressurized water and a receptacle for the exit water to go. A sink is ideal but perhaps that isn't practical for your needs. But you could set the aspirator up at the sink and run a long hose from it to your collection container.

For pulling fluids out of otherwise unhandy-to-empty things like lawnmowers and the like I made a setup out of a wet/dry shop vac. The vacuum hose plugs into the lid of a bucket, and a second hose goes between the bucket and item-to-be-drained. The liquid ends up in the bucket, where it can be easily disposed of or recycled.

One problem I found with the bucket approach is that my shop vac can create a good enough vacuum to cause the bucket to partially collapse. Reinforcing the inside with a metal band would do the trick (I haven't done that with mine yet). Another approach would be to repurpose an old pressure cooker, virtually free if you find the right garage sale.

One thing to keep in mind with respect to vacuum pumps is that the pressure differential can add up to a lot of force acting on the container you are using. 14.7 PSI adds up fast, so it wouldn't take a very large vessel to get to some rather substantial force trying to implode or squash your container.

 

[middle.road]

Thank you gang for saving my butt - as usual.
I've been around vacuum pumps used on particle accelerators, and messed with the HF ones, this one looks to fall in the middle between those.

I've lost out to the Big C, throat cancer. It's been a heck of a year.
First they tried Chemo, ended up sicker than the proverbial dog. Then when they did a CTScan to check progress, the tumor had grown 2x in size.
Had to resort to Plan 'B' which is pretty drastic, a total laryngectomy. That's the total removal of the Larynx and Vocal Cords.
So now my voice is gone. Get to relearn eating, swallowing, and speaking with a electrolarynx.
Currently have a tube 3" long going into the hole in my throat. It gets clogged up with mucus several times a day and
that is where the suctioning comes in.
After the laryngectomy there was a month of radiation therapy which burns your neck inside and out along with your mouth.
I can honestly say I don't wish this experience on anyone.

So it boils down to trying to saving the bucks whenever I can.
They nickel and dime you to the max.

 

[middle.road]

Hi Dan,
I have access to some small capacity vacuum pumps, around 22”Hg.
Similar to the Gast pump
I can donate one for experimentation.
They are single stage diaphragm pumps. They have stainless steel valves, made for food service machines.
They run on 115vac, approximately 4 amps draw . Quiet operation.

Alright Mike, go ahead twist my arm, I'll let you. UlmaDoc to the rescue.
I just told the wife and she said "isn't he the guy in California who is always sending you goodies?

Thank You.

 

[middle.road]

I took picts this afternoon and forgot to post them.