Find a hole saw very close (though not always identical) to the internal
diameter of the pipe glued into the fitting you wish to release it from.
This will almost certainly not work for ABS. Also, you will want to do this in
a well ventilated room.
An alternative to the above would be to use a "dagger" hacksaw to cut the
tubing into segments carefully to avoid cutting into the fittings glued
surface, then using pliers to tear out the segments. This is frustrating and
A last method is very expensive. Purchase a cutter to mount on your drill
(north of $60) that just fits inside the fitting and cuts (mills out) the
tubing. Then reprime and reglue.
Unlike air, water cannot be compressed. This fact makes it so that when water
flow is shut off abruptly by an appliance, such as a washing machine,
dishwasher, toilet or refrigerator ice-maker and water dispenser, the inertia
of the flow hits the new obstruction (valve) and, having nowhere to go as well
as not being compressable, it slams back against the water behind it. This is
called "water hammer."
Slower action valves such as bathroom vanities, kitchen sinks, showers and tubs
can reveal water hammer if they are used abruptly. Typically, these are turned
a bit slower which reduces or eliminates water hammer.
Water hammering in your pipes will make vibrations in the walls where the pipes
run sounding like anything from a light hum to someone running a jackhammer.
This isn't a harmless phenomenon for it can loosen or break connections and
fittings resulting in leaks.
The best solution is usually to install special devices, called
arrestors, that separate off an air bubble inside pipes near appliance
fittings. Unlike water, air can compress. Arrestors are built moreover with the
ability to separate the air from the water's natural tendency to absorb the air
into itself. In the old days of plumbing, plumbers installed funny little
"pigtail dead-end" bits of pipe near valves to accomplish this, but the whole
system had to be frequently drained and filled with air in order to replace the
missing air after it dissolved into the water.
If you hear hammering when your toilet stops filling after a flush, installing
an arrestor under your kitchen sink will not change anything. If you install it
as close to the offending valve as possible, it will likely solve your problem.
Older washing machines suffered from this problem too, but...
...new, water-saver washing machines create worse problems still. When they
start up, they fine-control the washer's behavior by turning the water on and
off repeatedly. 15-20 times per load of wash has been observed on some washers.
This puts a lot of stress and strain on the plumbing.
Note that even older machines created potential water hammer every time they
did the initial fill, did the rinse fill, and spray-rinced the clothes during
the spin cycle. New-fangled machines just do a lot more of this.
In the case of arrestor for washing machines, they are very easily installed
since you unscrew the hose connections from the wall, connect them to the
new arrestor, then connect the arrestor to the back of the washing machine.
Other water-hammer arrestors range from challenging to easy to install. Each
situation calles for what's usually sold as a special purpose water-hammer
This involves shutting off water to the toilet, unscrewing the water line to
it, mounting (the black-plastic connector of) the arrestor to (the bottom of)
the toilet flush water inlet, then connecting the water line to (the other
fitting on) the new arrestor.
Shut off the water, cut the plastic or copper water line, install the new
arrestor using its compression fittings. Do this as near to the refrigerator as