ZENY 3,5CFM Single-Stage 5 Pa Rotary Vane Economy Vacuum Pump 3 CFM 1/4HP Air Conditioner Refrigerant HVAC Air tool R410a 1/4 Flare Inlet Port, Blue

It is a toy single stage pump, but for the price it actually seems to work reasonably well. It is rated on the compliance plate at 5 Pa ultimate vacuum (or about 37.5 micron). I get about 120 micron out of it with nothing but the thermocouple gauge. Like most pumps it will bubble and spit some oil out when pumping a gassy load, a small trap would prevent this, I'll likely make one for it.I suspect the oil it ships with is not very good vacuum oil. It has a distinct odour which is generally a bad sign, if you can smell it the vapour pressure of something in it is non-trivial. I will replace the oil with a high quality vacuum oil and see if it can pump a bit lower. Anything around 100 micron is pretty good for a single stage pump anyway, for $60 bucks I am not disappointed.No sign of ceasing or an exploding motor-start capacitor as others have reported yet, but I have only run it for an hour or so.

This pump survived only just two months of infrequent usage before it stopped powering on. When it worked, it was very effective and fairly quiet too. I would recommend this pump if not for the fact you might have to replace it soon after you purchase it.

 Every winemaker should get this vacuum pump.If you aren't familiar with Wine Degassing, you can read more online, but in a nutshell, "degassing" wine removes the CO2 that is created when sugar converts to alcohol. When you leave CO2 in wine, it tastes bubbly, and leaves a foul flavor.I've tried several other products to degas my wine before looking at an actual vacuum pump:* A handheld vacuum, often called Wine Pump or Vacu Vin. This is a six-inch tall pump with a rubber stopper designed for removing the air from a single bottle of wine. This works, but only pulls up small bubbles and takes a lot of effort to get a very small result.* A metal rod wine whip. This is a straight metal rod with two plastic flaps at the end that you attach to a power drill and stick into your wine bucket or carboy to spin the wine around and stir up the bubbles. This was essentially, for me, an electric version of the Vacu Vin. Not much of an improvement, and took a lot of time.* A Wine Whip degasser. This is a C-shaped plastic rod (much like the metal rod) that you also attach to a power drill and stick into your wine bucket or carboy to spin the wine around and stir up the bubbles. It works pretty well, better than the metal equivalent in my case, but takes a lot of time and only gets slightly larger bubbles than the Vacu Vin.* A Vacuum Sealer. This is a completely different product. These are used to vacuum seal food. There are a lot of examples online using a Vacuum Sealer that use the accessory port (normally used for things like sealing Mason Jars) to degas the wine. I haven't tried many of these, but my Vacuum Sealer had a safety mechanism that shut it off when it hit a certain amount of pressure, so I had to restart it over and over. In the end, it never got more than small bubbles.So I started looking for a proper Vacuum Pump; no shortcuts, just a real electric vacuum pump.If you've looked at these much, you probably know that they are pricy. Most of the local big-box stores didn't even carry them, and even the few that did started over $100. At the time that I purchased this unit, it was $48 plus about $10 shipping.I researched the different types of pumps: single stage, dual stage, etc. For Winemaking, a single stage looked like it was going to do the trick. The main advantage that I found in this research was that a dual stage would eventually be quieter as it was running. However, this vacuum pump isn't loud at all. I measured the decibels that it put out after warming up. With the decibel meter 6 inches away from the pump, it produced 64db. This is pretty low, in my opinion. This doesn't sound like an air compressor; it sounds more like a washing machine, dryer, but probably closer to a dehumidifier. This is not loud at all.The vacuum power on this is more than enough for a 23 liter (or 5-6 gallon) glass carboy.You are supposed to put another drip container in between your carboy and the vacuum pump when you start. I had read about how important it was to make sure that you don't get any wine or fluid into a vacuum pump, but having tried the above mentioned methods, I was expecting a slow start when I plugged it in, so I hurriedly skipped adding a drip container, but was ready to pull the hose off in case it started to fill the hose with wine. I am so glad I was ready. When I first turned it on, it degassed so fast! Bubbles shot to the top and wine was in the tube faster than I expected, and I was able to rip the hose away from the pump in time! But be careful, this thing can degas quickly.After that, I connected a drip container and turned it back on and it is pretty amazing how well this works. I was using spare hose, not air hose that is reinforced, so the hose and tubing collapsed on itself and pinched, slowing down the airflow. Tomorrow I'll be heading out to get proper air hose, a relief valve, and probably even a regulator so I can monitor the pressure. This thing works very well and is a great deal!

I'm using this to rack and degas homemade wine and it works like a charm. Pulls sufficient vacuum to get all the CO2 out of the wine. The only reason I'm leaving 4 stars is because of the oil level gauge. Make sure to tilt the pump after adding oil. I added oil multiple times because the gauge kept showing that I hadn't even reached the minimum level. I assumed the pump had a large resivoir so I kept adding the supplied oil. Little did I know that the gauge lens wasn't being filled because of the design of the pump. So all in all a great pump just make sure to add oil conservatively.

I think that for the price, this is an excellent pump! However the motor tends to stick and requires me to give it a manual turn with a flat-head to loosen it up. The unit will also shut off when the vacuum reaches a certain level (I don't have these measurements) which I find annoying. Otherwise its a great unit and well worth the money.

GREAT!!! I use for many things. It goes to -28 Hg every time. I also use it to de-gas red/white wine, when i use it for that, the pump stays on for a few hours at a time and never has an issue, it blows a little oil smoke, but that's a very common thing with vac pumps, don't be alarmed. Great deal too for $55 bucks!!! I also use it for BHO. Works like a beautiful THC princess.

The pump ran just fine the first couple times I used it. It did the job I bought it to do. It didn't come with the proper attachment for what I wanted to do with it which is put a vacuum on an automotive air conditioning system but I knew that up front.The PROBLEM comes from the fact that this thing leaks oil terribly. I used it a couple times after I bought it in September, but by late October I was talking with ZENY's customer service department because of how much oil this thing was leaking. From the bottom of the unit as well as the side plate where it mounts horizontally. I found at least two different places it leaks from (there are likely more but I'd have to take it apart which would void the warranty!), have the photos to prove it, and I tried to get a warranty replacement. Of course their customer support group has gone 100% quiet without any resolution. I'm lodging a complaint with Amazon on this one - it is not usable in this state.

Surprisingly effective for the cheapest rotary vane pump on the market. As the reviewer below notes, if you need good pumping speed down to low pressure (<10^-1 torr), then you should buy a real three stage pump from a real company like Edwards, Pfeiffer, etc. However for hobbyist use this is awesome. Pretty slow pumping speed, but with no significant leaks you should be able to get to a low ultimate pressure. I wish they had an oil mist filter on this, but I certainly can't complain for $62!

👍🏻👍🏻 Works will well

Wow used it once for 30 mins and it broke

inexpensive and works awesome!

Works great

This is an additional pump we bought for use in our shop when we are stabilizing material. Works well but gets a tad hot....so watch yourself. Would buy again.

Muchas gracias ese lente equipó

works the way suppose to, make sure you putting oil in the pump before start-up, no issue! works well.

Works as intended

After whipping the gas out of wine with an electric drill paddle for years and never getting all of the gas out, this is a dream.

Worked great