Solving water hammer
If the inspectors in California don't care in your city, that's fine, however I wouldn't suggest that anyone using the UPC codebook try it unless they don't mind doing the work twice.
There are a lot of licensed plumbers here that know plumbing code.
There may be things a handyman could do, and maybe even get away with. It's not something that we would recommend, Questions here tend to be answered as if the intentions is for it to be both legal and inspected.
The reason air chambers have been replaced with hammer arrestors in the code book, is that they do a better job.
Testing has proven that air chambers will fill with water.
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Although arresters are typically tested to 10,000 on/off cycles, Sioux Chief arresters have been lab tested to 500,000 cycles without failure. All Sioux Chief arresters are guaranteed to control water hammer for the lifetime of the plumbing system." Sioux Chief
The one on the left is for a washer.
The one in the center can be soldered onto a tee.
The one on the right can be used inline like for a lav supply or an icemaker line.
601.10 Water Hammer. All building water supply systems in which quick-acting valves are installed shall be provided with devices to absorb high pressures resulting from the quick closing of these valves. These pressure-absorbing devices shall be either air chambers or approved mechanical devices. Water pressure shock arrestors shall be installed as close as possible to quick-acting valves at the end of long pipe or near batteries of fixtures or both.
601.10.1 Water Chambers. Where air chambers are installed, they shall be in an accessible place, and each air chamber shall be provided with an accessible means for restoring the air in the event that the chamber becomes waterlogged.
601.10.2 Mechanical Devices. Where listed mechanical devices are used, the manufacturer's specifications as to location and method of installation shall be followed.
Approved water hammer arresters shall conform to the ANSI/ASSE 1010 - 1996 Revision arrester standard (sizes AA-F). Note: the AA size arrester is adequately sized for each application required in this model code.
Since an approved arrester is required by the ANSI/ASSE 1010 Standard to provide continuous protection from water hammer without maintenance, access panels shall not be required.
Other arresters, air chambers or expansion tanks installed in any other part of the plumbing system not specified in this model code may not be considered a substitute for the minimum requirements of this code.
http://www.siouxchief.com/B_WaterHammer_Code.cfm