Eastman 2-Gallon Mini Thermal Expansion Tank, Stainless Steel Hammer Arrestor with 1/2 Inch Threaded Connection, 60008

Just as described. Crazy to think this replaces my old expansion tank. Can't beat the price.

I put this on the input to the pressure regulator to absorb the water pressure surge when the pump comes on. It keeps the pressure switch from hammering on and off.

We replaced or clothes washer with an HE version. The new washer ware control valves are quick close and created severe water hammering. I tried the AA size anti water hammer device. Still slammed the pipes. I bought this larger unit that is designed for a water tank up to 2 gallons. It is small and was able to squeeze in to my arrangement. I had to install a wye to replace the multi tap AA device. But now all is silent. This device has an air chuck to adjust the pressure. A QR code directs you to instructions that simply say “pressurize to 3 to 5 psi above normal pressure”. It would be nice to say that on the permanent tag on the unit or at less have the QR code on the device, not the box.

This micro expansion chamber is marketed principally for thermal expansion protection of in-line tankless or on-demand water heater systems, which it should be great for. A secondary use is for water hammer reduction, which is what I purchased it for. Pros include the fact that it is made by Eastman, a reputable supplier of thermal expansion protection products. I have a full size unit to protect my tank-based water heater system and have been very pleased. This micro-expansion chamber exhibits the same quality. Pros: good manufacturer; straightforward installation requirements; stainless steel construction. Cons: no installation or service instructions; incorrectly listed in the product description as having 2 gallon capacity (this is incorrect - it is meant for 2 gallon capacity tankless water heater systems but the chamber itself is likely about a cup in volume). As mentioned by another viewer, setting the pressure is very difficult. There is so little volume in the air-portion of the unit that getting the right pressure and then keeping it from bleeding off when you remove the air chuck is a challenge. In summary this is a very good unit possibly worthy of a 5 star review were it not for the difficulty adjusting air pressure, the need for installation documentation, and a necessary correction to the sales listing. The unit reviewed was made in China.

Sure beats the bjesus out of the ST-5 tank.

Work just for what I wanted it for. Used on washing machine to stop water hammer.

Nice quality

Think of an expansion tank as a shock absorber for your plumbing system. Every time your washing machine cuts off the flow of hot water by slamming a valve shut...; this device cushions the blow to all the pipes.

Eliminated pipe knocking caused by the washing machine completely. It comes with 1/2NPT thread, so you would need an NPT to BSPP or BSPT to use it in some country.

Exactly what I needed for my tankless install. A necessary accessory to eliminate water pressure spikes from damaging your heat exchanger located inside your tankless water heater. Also installed when using a tankless water heater with radiators to keep a house warm. The thermal expansion of water will cause a pressure increase in the water lines. The pressure can burst the heat exchanger inside. Don't let anyone tell you otherwise, plus manufacturer warranty requires one installed so don't be caught by losing warranty. These eliminate most of the pressure spikes experienced in the water supply line when water is being used by appliances and even faucets. These are fitted with a "T" on the cold supply side of the tankless water heater. You'll need a water pressure gauge to find out what your water pressure is and then using a small bicycle pump, adjust the pressure of the internal membrane to match your water pressure. That's a vital step so it counters the spikes. In addition, this alleviated an issue I had where anytime cold water was being used, it would turn on the tankless water heater only for it to realize hot water was not being requested. Why this was occurring is due to a pressure drop in the water lines and the tankless' sensor detected this and thought hot water was being requested. Once I installed this thermal expansion tank the issue went away. In addition, this also lowers the usage on the tankless making it last longer.

Excelente para bajar los picos de presión por un boiler de depósito pequeño de rápida recuperación en un sistema cerrado. Aunque está recomendado para boiler sin depósito. Mi sistema llegaba a 110psi y logré bajarlo a 75psi Recomendado

Works like a charm! I installed it in the feed line of water heater and it solved the water hammer from my toilet valve on the second floor.

Worked great on my Natural Gas tankless water heater. Much better then having a big tank attached down the line!