inside an American made anti water hammer device

Claims to be not an electrical video. Joke's on us. Turns out it's a capacitor, but for water.

A lot of people think that the residential water pressure in the US is only 1/2 of what you have in Britain. This isn't true. We actually have the full pressure coming into the house. It's just that we center-tap the supply and split it into two "legs". It's the reason why it takes so long here in the US to fill a kettle. You'll be relieved to know that commercial buildings have three phase water pressure.

As someone who not only was a sales man for these products, but also has toured the Sioux Chief factory in Peculiar, Missouri, these things are sold by the tens of thousands. The tube is just spin closed at the end by friction, then the piston is inserted and that traps the air at the top of the closed end. Then is squeezed at the other end to trap the piston. Then, depending on what you ate connecting it to, that tube is soldered to the tee with the appropriate fittings. Available in hose thread, like you have for connecting to washing machines in the US, PEX ends, copper tube ends, and threaded copper tube ends. They make several different sizes with the MiniRester designed to be mounted as close as possible to the problem valve. They also make larger units designed for whole house protection and unuts with internal stainless steel bellows for commercial applications.

The inverted "T" was very common in the USA, near washing machines and dishwashers with fast powered valves likely to cause water hammer. It can eventually lose effectiveness (the air dissolves into the water over time), the fix was to drain down the pipes entirely (so all lines are full of air). When the water is turned back on, the vertical stub maintains an air pocket again for years, if not decades.

I my father was a plumber. When I was a kid, he did a lot of new construction work. He taught me how to run copper lines and all the steps involved, including adding air chambers at the end of each run and at every fixture. Just a tee with a 12 inch vertical capped length of tubing as close to the valves as practical. Never had a water hammer complaint. He was religious about flushing water heaters and draining water systems once a year. One reason was to "recharge" the air chambers. We could knock out one of these services in about an hour usually. The extra valves, caps, or plugs he installed during rough in made it quick and easy. Years later, the code changed an all businesses and residences were required to install backflow preventers between the meter and the first fixture or tap. Faucets, water heaters, and pipes started leaking all over town. But not at the places we installed the copper. All those air chambers were evidently enough to handle the thermal expansion.

I worked in the Tool and Die department as a Machinist before my health forced me to retire early. This really is a top notch company.

Surge protection device, only for plumbing rather than wiring, and fully reusable too :)

Pretty commonly used here in Australia. They make different types depending on what your mains pressure is. High pressure areas need a stronger water hammer arrestor. Some actually do seem to have a spring in them, you can hear it scrunch when they operate. Apart from the noise, a water hammer will eventually damage a copper pipe because the hammer/movement causes the copper to work harden and eventually it will get fatigued and crack. Similarly, plastic pipe gets more brittle as it ages and more likely to crack from a water hammer. As a metal worker, that one looks like it's friction welded on the flat end. They're made out of a simple piece of copper tube. It's a common manufacturing technique. For the threaded end the tube is heated and then pressed into a die to neck it down and then a thread can be cut on the narrow part since the material wall is now thicker. For the flat end, it's heated and pressed down flat but with a very narrow tube. A conical die is then spun very fast to friction heat and weld the narrow pipe shut. That's why it looks the way it does. It is literally called "friction welding" and is very economical to do at scale since the tooling is usually simple and you don't need any shielding gas. For the necking down operations sometimes they are heated very quickly with a very hot flame (oxy/lpg or similar) but sometimes they just spin the part very fast as they push it into the die. You can normally tell which one it is by looking at the marks left by the tooling (which is the giveaway for the closed end in this case).

100% accurate. The inverted T was extremely common in homes from built/renovated 1940s to about the 1980s when arrester devices became common. Most of the homes throughout the Midwest and west coast build in the post World War Two boom had inverted T setups. Surprisingly in the New England coast you saw this a lot less. Many more towns tended to have lower pressure supply systems or they predated the requirements for back flow prevention systems on the city water supply. So many houses just depended on the water main to kind of act as a buffer or even the water heater (and usually washing machines were in basement close to the main supply). Of course in cheaply built homes with PEX you now get people complaining about “things moving in their walls” as badly secured PEX flops around.

My highschool physics teacher had a glass tube under vacuum with a small amount of water in it, to demonstrate water hammer. It was impressive.

I've got drawers full of these at work. I test and refurbish dishwashers/washing machines/refrigerators etc, and these are a necessity on the outlets of our water manifold system. They're also really handy if I need to make some kind of adapter or coupling; just cut the ends off and sweat them onto some pipe!

I do really enjoy your videos where you're a little more out of your element. Makes me feel like I'm not alone in not knowing how anything and everything works. The genuine joy and inquiry in your voice as you ponder how it works always makes me smile!

1:01 Those of us who are on well water (Emergency system for my family. Primary is treated "city water.") usually have one of these to smooth out the water pressure coming from the well pump. They still allow 10-15 psi change as the pump switches on and off. The large ones used with well pumps have the air pressure range stamped into them, so you can refill the air above the diaphragm.

Many years ago I had a tour of Bonnington hydroelectric power station. They have a gigantic version of this device - a surge tank (difficult to see but I would imagine about 20 feet diameter and 30 feet tall) fed by 2 6ft diameter pipes.

Air-bladder expansion tanks are now required pretty much everywhere in the US. If you have city water, regulations require a backflow prevention valve at the street, for sanitary and anti-terrorism reasons. An expansion tank is installed at the water heater to prevent high pressure developing due to temperature changes. If you have well water, you have a giant bladder pressure tank unless you have a fancy VFD-based well pump.

I drove past the Sioux Chief plant all the time growing up, and always wondered what they made in there. Never would have guessed a Brit would be the one to tell me. Neat video, thanks for the info!

The trouble with the dead end pipe is after time the air would diffuse into the water and eventually disappear. And yes, they don't allow it in modern plumbing inspections.

The third and often overlooked solution, if you don't wish to modify your plumbing, is to simply crack open the valves to the washer just enough to limit the flow rate to where the velocity of the water in the pipes is not enough to cause a hammer situation. The only side effect is that your washer will take a little more time to fill.

For a moment I thought this was a rude product and you were speaking in code again.

Good to see your hand on the mend.