[Shop-talk] Fwd: Re: Well water hammer?

[Jim Franklin]

On Aug 26, 2014, at 2:01 PM, Randall wrote:

>> You need to check the Schrader value with the tank empty of water and no
>> pressure on the water side (drain open).  With the tank empty of water
>> there still should be some pressure on the air side of the bladder,
>> can't remember the amount.
>
> Another, less scientific approach, is to just close off the inlet and open
an outlet where you can see it.  Wait until the flow stops, then add a little
air.  If you get some more flow out, add a little more air.  Repeat until the
extra air doesn't dispel any water.  That will still be less than it should
have, but enough to prevent water hammer and rapid cycling.
>

What's causing the water hammer? I've never heard of it when something turns
_on_.

jim