Mini Thermal Expansion Tank

[Size: 2L, Number of Items: 1, Size: 2L, Number of Items: 1]
This is an excellently built expansion tank that suits my hydraulic ram pump applications perfectly. Really nice polished exterior sheds water and dust. Well machined half inch male plug is welded to tank so there's one less fitting to come loose and leak. Great durability and wall thickness without being heavy and cumbersome. I like that its pre-charged with air so its ready to go out of the box. I also like that I can easily access the valve stem on top if I do need to adjust pressure internally due to ambient temperatures and atmospheric pressure differentials. Great value and well worth getting.

[Size: 2L, Number of Items: 1]
Came pre-charged to about 75 psi, and insulation is easy right off of my hot water heater, which is in the same room as the washer and dryer, and it essentially eliminated the water hammer that we were trying to address with this tank.

[Size: 0.5L, Number of Items: 1, Size: 0.5L, Number of Items: 1]
I got the 0.5L (model WJ-03-0,5L-S) but really wasn’t sure how big it would be. Photos show actual measurements of about 3.5” diameter and 4” length. I will be using this to replace the much smaller hammer arrestor (about 0.5” diameter and 2” long) on my recirculation pump (see photos). The small size and 1/2" MNPT connectionis perfect for a direct replacement. I don’t think this smaller size would be sufficient for a water heater expansion tank though.One important note is that there are no instructions provided in the box, I took off one star for that. In particular, no information is included as to what pressure the tank is actually delivered at. That said, I finally did see a sticker in one of the ad photos claiming 40psi (hard to read and had to zoom in). I would have preferred basic product instructions were provided with recommendations on proper pressure for individual use cases. For a previous installation (different application & bigger tank) I read that one should adjust the air pressure in the expansion tank to match the measured water system pressure. As our static water pressure is about 55psi, I’m guessing 40psi would be on the low side but am not entirely sure. Also not sure if that rule would be different for a water hammer use vs expansion case use.

[Size: 2L, Number of Items: 1]
We had a tankless water heater system installed last year and really like it, except for the water hammer noise that comes from the pipes. (We had a tankless system in our previous home and it didn't do that, I don't know why.)Our plumber recommended we get a mini thermal expansion tank.It's made from 304 stainless steel meaning it won't corrode or rust, not even in humid or outdoor conditions and it's safe for drinking water.It's designed for tankless water heaters and provides consistent, reliable pressure stabilization to reduce the water hammer effect.The plumber said it looked well-constructed. Installation was uneventful. He said everything lined up and afterwards there were no leaks.And, it definitely improved the water hammer noise significantly. We still get the vibration every once in a while, but it's nothing compared to how it used to be.We are very satisfied with this expansion tank and recommend it to other homeowners with tankless water heaters.

[Size: 2L, Number of Items: 1, Size: 2L, Number of Items: 1]
Solid build, but long-term reliability is still unknownI purchased this 2L thermal expansion tank for a tankless water heater installation. The stainless steel construction feels solid and is a nice upgrade over painted steel since it should resist rust and corrosion over time. Installation was straightforward thanks to the standard 1/2" MNPT connection, and it fit without any issues.So far, it appears to do its job by helping stabilize pressure, and I haven't noticed any leaks or manufacturing defects.The only reason I'm giving it 4 instead of 5 stars is that this is a relatively new product with limited reviews, so it's difficult to judge its long-term durability and reliability. If it continues to perform well over the next year or two, I'd have no hesitation recommending it.Overall, it's a well-built product at a reasonable price, and I'm satisfied with the purchase so far.

[Size: 2L, Number of Items: 1]
Ordered the 2L version for a water system in a camper van, it should make for a viable whole system hammer arrestor. The 2L size does not denote 2 liter, which would be much larger than the volume of this device.The smaller ones might a better pick if you have limited space, and/or you are just trying to address an issue with a single device.Appearance is very nice, seems to be very well made.Make sure to install it in a position that allows access to the air pressure valve.My only grumble is that the listed price of $71 seems a bit steep