Replacing pressure gauge on water holding tank

Question

The water coming in from the well is supplied by thick rubber type pipe cut and angled with metal bands. There is no cut off valve to the water holding tank.

I need to replace the pressure gauge (leaking from bototm). Well is 250ft deep. I understand that I can turn off electric to the well and should cut off the water supply. There is no cut off for the water coming in from the well.

I believe I need to cut off electric to well, release pressure (can open a faucet), quickly put on the new pressure gauge, turn electric back on and turn on water. I talked to someone who said the little amount of water leaking out of the 1/4 inch hole would be insignificant, the water would have to drain back to the pump before I have a problem.

I would like any comment on installing the pressure gauge. Can anyone comment on how to install a cut off valve from the pump coming from the wall to the holding tank. The metal clamps are looking old and there are about four elbowed sections from the wall (well into house) to the holding tank. If I cut off the electric and disconnect the hose to the holding tank and the water drains back to the pump, how do I know it did that and what are the steps to get the water back up the tube

At some point I want to replace the hole unit, don't know the tech terms, but the water release valve handle is gone and the "gray box" that trips the pressure gauge to work all need to be replaced. I don't want to try that until I have enough money to call a plumber in case my attempt goes wrong.

Answer 1

There is no need for (and good reason not to have) a valve between the well and the pressure tank. Turn off the pump power, release pressure, change the gauge. There's no need to hurry. The well is below the tank, with no power to the pump the only way water will even want to flow is back to the well, though if the check valve on the pump is in good shape it won't. There should be a drain valve near the tank...drain all the water in the tank and take as long as you like to fix it.

Edit: either shut off the valve between the tank and the house (assuming there is one, there usually is), or shut off your water heater if there is no such valve, as draining or partially draining a water heater that's turned on is a bad thing...

If you add a valve where you suggest, you could have the valve shut off while the pump power is on, and your pressure switch would see low or no pressure (valve shut) and send power to the pump, which would duly pressurize up to the the shut valve, and eventually find the weak point in the system between the pump and the shut valve, blowing it open. Bad idea.

Likewise, if your pipes are not leaking, don't mess with them. Polyethylene pipe (what you probably have, not rubber) is not all that easy to work with, especially if you have no experience and it's old. If it's not leaking, save the experience for when you have a reason to get it. "Looking old" is a rather vague description - I have plenty of "old" hose clamps in service, they have been mostly made of stainless steel for quite long time, old and dirty (or even light surface rust, as even stainless can get) is not a problem (they are on the outside of the pipe.) 40 years old and just fine. If you have an oddball that's actually rusting to the point of being compromised, sure, replace it, but don't take the pipe apart.

When you are done, simply re-apply power to the pump, and run water until all the air is out of the pipes - this will often result in "alarming looking" but perfectly benign sediment being knocked loose, so don't be alarmed if that happens, just run the water until it clears up, and perhaps remove your faucet aerator screens and clean them. Very shortly (seconds) after you restore pump power you should hear water in the pipes, and see pressure build in the gauge you replaced. Sometimes you have to fiddle with a lever on the gray pressure switch box (if it has a low-pressure cut off.)

Answer 2

Cutting off the pump and draining the tank down are all that's necessary. If you're quick and ready (have one to two wraps of teflon tape install on valve, a few bath towels on hand), you can easily swap out the valve. As you slowly remove the valve, let the residual pressure off.

Disconnecting the black pipe will be a disaster. Chances are, a little heat may have been used to soften the plastic to make the connections, removing them may be very, very difficult. You'll probably break something.

However, while the pressure is down, replace those rusty hose clamps.

Good luck.