Best water hammer arrestors

The Sioux Chief 660-HB is the arrestor I’d put on most washing machines. It threads straight onto the hot and cold hose valves behind the washer, and the washer hoses thread onto it. There’s no pipe to cut and no wall to open. This listing is a two-pack, which is what one washer needs.

Why two? Sioux Chief’s install guidance puts one on the hot inlet and one on the cold. A washer fills through solenoid valves that close fast, and either side can bang. Sioux Chief’s sizing guide lists washing machines as a point-of-use job for an AA arrestor on both lines.

Both ends are ¾ in. hose thread: a female swivel nut for the valve and a male thread for the hose. Sioux Chief says not to put thread sealant on the swivel threads. The rubber washer inside the swivel nut is the seal, the same way a washer hose seals.

Measure before you order. Sioux Chief’s spec sheet lists 5 in. of overall height, with the hose outlet 3 in. out from the center of the tee. In a recessed outlet box, or with the washer pushed tight to the wall, check that the hoses still clear without a sharp kink.

The chamber is 304 stainless steel and the tee is UNS C36000 brass. Sioux Chief rates it to 250°F and 250 psig and says it’s burst tested to 1,500 psig. It’s certified to ASSE 1010 as size AA, the size Sioux Chief’s guide calls for at a single fixture.

Inside, a piston with O-ring seals rides on a sealed charge of air. When the washer valve slams shut, the moving water pushes the piston up into that cushion and slows down, instead of stopping dead at the valve. Sioux Chief’s white paper calls the air charge permanent.

My call: if the bang comes when the washer fills, start here. It was new and in stock from Big Frog Supply, not Amazon.com on Oct 21, 2026. If the laundry box is being replaced anyway, a box with built-in arrestors is the other route. Our washing machine outlet box guide covers those.

The 660-GTR1B goes on the small stop valve under a toilet, sink or dishwasher. Many of those stops have a ⅜ in. OD compression outlet. This tee threads onto that outlet, and the supply line threads onto the tee. It’s a tidy fix for a bang you hear when a toilet tank finishes filling.

Sioux Chief’s GTR sheet says it installs directly to supply stops, hot or cold. One side is a female compression nut that fits the stop’s outlet. The other is a male compression thread for your riser or braided line. The trunk adds 2 in. between the stop and the line.

Sioux Chief says not to use pipe dope on compression threads. The seal is the ferrule or the cone washer in the supply line, not the threads. Snug the nuts, open the stop slowly and check both joints for drips with a dry paper towel.

Pick the size by the stop’s outlet, not the pipe in the wall. Sioux Chief makes the same tee as the GTR0 for ¼ in. OD outlets, which you see on ice maker lines, and as the GTR for ⅝ in. OD. The GTR1 is the ⅜ in. OD version.

The chamber is 304 stainless and the tee is nickel-plated no-lead machined brass. Sioux Chief rates it to 250°F and 250 psig and says it’s burst tested to 1,500 psig. It’s listed to ASSE 1010 as size AA, to cUPC, and to NSF/ANSI/CAN 372 for lead content.

One thing to check on the listing. The “B” at the end of the model is Sioux Chief’s bulk-pack code; the clamshell retail version is the 660-GTR1. The Amazon listing doesn’t say how many come in the box, so read the quantity before you order for several fixtures.

My call: it’s the arrestor for anything on a ⅜ in. compression stop, from toilets to dishwashers. It stands 4 in. tall, so check that it clears the cabinet floor or a drawer. It was new and in stock from Summer Valley Supplies on Oct 21, 2026.

The 660-TK fixes the same toilet bang from the other end of the supply line. It threads onto the fill valve’s threaded shank under the tank, and your supply line threads onto it. Sioux Chief lists it as a laundry and toilet tee that installs under the toilet tank.

Use it when the stop valve is old or isn’t a ⅜ in. compression outlet. A stop that hasn’t been turned in years is one you may not want to put a wrench on. The 660-TK leaves the stop alone: you shut the water, flush to drain the tank and work at the tank end.

Both ends are ⅞ in. ballcock thread, per Sioux Chief: a female swivel ballcock nut for the fill valve shank and a male ballcock thread for the supply line. A toilet supply line already ends in a ⅞ in. ballcock nut, so the line you have still fits.

Sioux Chief lists it in its GT family, with a 304 stainless chamber and a no-lead brass tee. That family is rated to 250°F and 350 psig and burst tested to 1,500 psig. It’s certified as an ASSE 1010 AA arrestor, the point-of-use size for one fixture.

Why does a toilet bang at all? The fill valve shuts as the tank reaches its level. If it shuts quickly, the moving water in the line stops all at once and the pressure spikes. Sioux Chief’s GT sheet says to put an arrestor within 6 ft of the valve that causes the shock.

This one sits right on that valve. Like the hose thread model, the swivel nut seals with its washer, so skip the sealant on the swivel threads, per Sioux Chief. It does add the tee’s length between tank and line, so a short rigid riser may need a longer braided line.

Our toilet supply line guide covers lines that reach. My call: choose the 660-TK over the GTR1B when you’d rather not touch the stop. It was new, in stock and sold by Consumer Supply Co on Oct 21, 2026.

The 660-S is the in-wall arrestor for ½ in. copper. It has a ½ in. male sweat tail that goes into a tee on the line at a tub or shower valve, a dishwasher stub or an ice maker. It’s the part to buy when the wall is open for a remodel or a repipe.

Sioux Chief’s 660 sheet says its sweat models also work with press fittings and push fittings. The Amazon listing names Viega ProPress and SharkBite. So on a press system, you put a ½ in. press tee in the line and press it onto this arrestor’s tail, with no torch near the framing.

If you do solder it, Sioux Chief says to solder the sweat connection and not to braze it. Clean and flux the tail like any copper joint. Our push-to-connect fittings guide covers the push option if you’d rather skip heat entirely.

On the sweat model the chamber is Type L copper, per the spec sheet, with a C69300 brass fitting. Inside, a polypropylene piston with EPDM O-rings rides on a sealed air charge. It’s rated to 250°F and 350 psig and certified to ASSE 1010 as size AA.

Height is where it differs from the PEX and thread versions. The sweat model stands 6⅜ in. tall, against 4 in. for the male thread and F1807 PEX models, and it’s ⅞ in. wide. Sioux Chief says it installs at any angle, so it can lie sideways in a 2x4 wall.

Sioux Chief also says no access panel is needed. That matters inside a finished wall, because not every arrestor maker says so. SharkBite’s spec sheet asks for an accessible location. Each 660 chamber holds 1.4 cu. in. and is rated for 1 to 4 fixture units.

The listing shows 660-SB, Sioux Chief’s bulk code for the same ½ in. male sweat part. My call: it’s the pick for copper or press work behind a tub valve or dishwasher. It was new and in stock from MaxWarehouse on Oct 21, 2026.

The 660-X2B is the same AA arrestor with a ½ in. PEX barb. It’s built to ASTM F1807, the standard for PEX fittings used with metal crimp rings. If your house runs on crimp PEX, this goes into a ½ in. PEX tee near the fixture with a short stub up to the arrestor.

Check your fitting system first. Expansion PEX uses ASTM F1960 fittings, and Sioux Chief makes that version as the 660-WG2B. Its F3347 PEX press version is the 660-GVPX2B, and its CPVC version is the 660-V82B. A barb from the wrong standard won’t seal on your pipe the way it should.

The chamber is 304 stainless steel on the PEX models, per the 660 sheet, with a C69300 brass fitting. It’s 4 in. tall and ⅞ in. wide, more than 2 in. shorter than the sweat version. That shorter height helps behind a washer box or in a tight joist bay.

Ratings match the rest of the 660 line: 250°F, 350 psig, ASSE 1010 AA and 1 to 4 fixture units. Sioux Chief says it installs at any angle with no access panel. So once the PEX passes its pressure test, it can live inside a closed wall.

Where it goes: Sioux Chief’s sizing guide puts an AA arrestor at the point of use on both hot and cold lines for washing machines, dishwashers, ice makers and tub or shower valves. On a PEX manifold system, that still means at the fixture, not at the manifold.

You’ll need a crimp tool sized for ½ in. rings, plus a go/no-go gauge to check each crimp. Our PEX crimp tool guide covers the tools. For a dishwasher, one arrestor on the hot supply is the usual setup, since that’s the only line it uses.

My call: it’s the PEX pick for a new rough-in or a remodel with the wall open. It was new and in stock from Big Frog Supply on Oct 21, 2026.

The SharkBite Max UR22632 is the no-tools pick for a ¾ in. line. It’s a tee: you cut the pipe, push both ends in, and the arrestor chamber rides on the side. SharkBite lists it for PEX, copper, CPVC, PE-RT and HDPE SDR-9 pipe, and says it can go on a wet line.

That makes it a quick fix on a ¾ in. trunk near a water heater or a main, where a ½ in. point-of-use arrestor isn’t the right part. SharkBite also makes a ½ in. version, the UR22630. Its spec sheet gives the ½ in. a lower rating, 125 psi max static.

Mark your insertion depth on the pipe first. SharkBite’s spec sheet lists 1¼ in. for ¾ in. pipe. Cut square and deburr the end before you push it on. Our push-to-connect fittings guide covers the prep and the disconnect tools.

The body is lead-free DZR brass, with EPDM O-rings and a 304 stainless retainer. SharkBite’s product page lists ASSE 1010 and NSF/ANSI/CAN 61 and 372. For HDPE, the spec sheet says to use a tube stiffener from the pipe maker.

Two of SharkBite’s numbers don’t line up, and I’d plan around the lower ones. The product page and the Amazon listing say 180°F and 200 psi. The spec sheet lists 250 psi max static and 400 psi max spike for the UR22632. Either way, 180°F is below the Sioux Chief and Zurn ratings.

Placement matters. SharkBite’s page calls it maintenance-free, but its spec sheet says it needs an accessible location for maintenance. I’d put it where you can reach it, like an unfinished basement or behind an access panel. It’s also big: 10.6 in. on SharkBite’s drawing.

RWC’s warranty lists 25 years for SharkBite brass push fittings used with copper, PEX and CPVC. My call: it’s the pick for an exposed ¾ in. line where you want no torch and no crimper. It was new, in stock and sold by Amazon.com on Oct 21, 2026.

The Zurn Wilkins 1260XL-B is the arrestor for a whole branch, not one fixture. It’s a PDI size B, which Zurn rates for 12 to 32 fixture units on a ¾ in. line. On Zurn’s table, two full bathrooms with flush-tank toilets come to 12 cold-water fixture units, the bottom of size B.

Zurn lists PDI WH-201, ASSE 1010, ANSI A112.26.1, UPC and NSF/ANSI/CAN 372. PDI sizing is how engineers spec arrestors on commercial jobs. In a house, it’s the right tool when one arrestor has to cover several fixtures on a long run.

The body is Type L copper with no seam and a C69300 brass tailpiece. Inside, a polycarbonate piston with EPDM O-rings sits on a 60 psi nitrogen precharge. Zurn says it installs in a stud bay with no access panel. It’s 7¼ in. tall and ⅞ in. wide.

Placement follows Zurn’s install sheet. Put one on the hot branch and one on the cold, as close to the shock as you can. On a branch of 20 ft or less, it goes at the end, between the last two fixtures. Over 20 ft, add a second one.

Pressure changes the size. Zurn’s spec sheet says to pick the next size up when flow pressure runs 65 to 80 psig. It also says arrestors perform best at 80 psi static or less. Above that, a pressure reducing valve comes first, and the code requires one anyway.

Seal it with Teflon tape only and put the wrench on the hex, not the body, per Zurn. The thread is ¾ in. male NPT, so you need a ¾ in. female tee or adapter. Zurn’s warranty runs 12 months from purchase.

Zurn’s irrigation bulletin puts a size B on a ¾ in. supply, within 4 ft upstream of the zone valve. My call: buy it when the bang comes from a branch that serves several fixtures, or from sprinkler valves. It was new, in stock and sold by Amazon.com on Oct 21, 2026.