Happybuy Air-Operated Double Diaphragm Pump, 1/2 in Inlet & Outlet, Cast Iron Body, 8.8 GPM & Max 120PSI, Nitrile Diaphragm Pneumatic Transfer Pump for Petroleum, Diesel, Oil & Low Viscosity Fluids

Worked very well.

This pump is a sad joke. It pumps, barely. I bought the unit allegedly rated for 13 gallons per minute.It's not even close. The pump is extremely loud and could barely pump 1 gallon per minute. At the same time, the pump uses huge amounts of compressed air. My unit arrived with bolts crossthreaded, so it will be very annoying to try to service it.More likely I will just toss it. $155 for a fraudulent piece of junk.Sadly, I didn't have time to put it to the test after Amazon's "return window" had closed. Nonsense! Stop selling this crap. I would give it zero stars if I could. Total ripoff.

Pump ran fine for 6 months then failed, no product support or warranty. Sold by Amazon but Amazon says not supported.

Well at first we THOUGHT the unit failed . It did not,there was an air flow issue and we did not notice it. They sent out a replacement ASAP.We discovered the problem was our own doing, so I promptly returned the new one instead of swapping .This pump is fast, and furious. It does more than the old twice it’s size unit we had and is amazing.We use it for hydraulic fluid exchanges in the field.Old out , new in.It’s great!!

This pump worked well for us. We pump some fairly thick polymers and we use a portable gas powered compressor. It pumps about 10 gallons a minute of the really thick stuff (like Elmer's Glue) and about double that rate with the thinner stuff. Also, my air drier failed and damaged the pump. After much research I found that the air side rebuild kit is ARO 637434 Air Section Service Kit and available on Amazon. If for any reason this kit does not work as expected I will update this review.

work better than i thought it would

I bought this as a backup pump for my soft wash roof cleaning setup and kept it in the box for a few months until I needed it. So it's well past the return date now. I hooked it up, and even with a 30 CFM air compressor, it hardly pumps well enough to get a slow trickle out the end of my spray hose. On top of that, despite the fact that the pump claims to be polypropylene, the middle part is made of steel. So it wouldn't have been suitable for chemical applications anyway. Figured at the price it was worth a try, but you don't even get what you pay for here. Maybe if it was enough to get me through a couple of jobs I would say I got what I paid for.

This pump was purchased to replace a diaphragm pump that had been in service for several years. It is used to pump waste water through a filter prior to going into the municipal sewer system. So far, it's been working great. It runs about 10 hours a day.The build quality and construction seem to be nice, it's heavy for it's size since it's made of metal. I hope this will last a while, like the previous one.