Pipe dope around the threads is also acceptable.

Lowe's, Home Depot, and I believe ACE all see water pressure gauges which you can screw on to a hose bib to read your normal house water pressure. Then you may need to borrow an air compressor and a tire gauge. You will find a shrader valve (looks like a tire valve) on the top of the new expansion tank. Connect the compressor tire fill adapter for a few seconds and the check the pressure in the tank until you get to your measured water pressure, then install.

In The Villages your water pressure varies. We check this on every inspection. You can use a pressure gauge on one of your hose bibs.
Most of The Villages around the middle and upper part the water pressure is typically around 50 psi.
In the newer areas, (like Fenney, DeSoto, etc.), it is about 70 psi. In the newest areas, like Bradford, Chitty Chatty, etc it is a bit closer to 60 psi.

Hope this helps!

Good advice, or as I did, call your brother-in-law!!

As Frank said you can put a pressure gauge on your hose bib and you can increase the pressure in the expansion tank with a compressor or go down to a gas station and try to match or set just below your house pressure reading.

And if you have someone replace the tank for you make sure they set the tank pressure correct during installation.

. I'm thinking that you are referring to someone else, as I only have one brother in law, who is a fiber optic installer 1300 miles away....lol.

I've found it easy to check by turning off the main water supply valve to the house. If the water still runs out of any faucet for 5-10 seconds when you turn one on the expension tank is working.

expansion tank
 

Tank is located above the hot water heater. There is a bladder inn the middle of the tank, the bottom full of water, the top full of air. If the top sounds solid when you strike it with your finger nail the bladder has failed. If it sounds hollow it's fine. For now.

Sounding hollow is ok but that’s only the first test.
The next step is to take a tire gauge and check the pressure in the tank and make sure it’s close to your house pressure. If the pressure is low or zero the tank needs to be replaced. There is a valve at the top of the tank underneath a cap and you can check the pressure.
If the tank is mounted so close to the ceiling that you can’t get the tire gauge on it then you can’t accurately determine if the tank is functional.
I have seen many hollow sounding tanks that had little or no pressure in them.

I have seen only a small percentage of tanks that tested good after 5 years. Keep in mind if the tank fails (and it will eventually )it can cause damage to your hot water tank, damage to your valves in plumbing fixtures, joints in supply pipes and major leaks.
Check those tanks and replace them if there old!!

You can also use a regular bicycle pump to pressurize the expansion tank.

One of my homes has a 21 year old HW heater.
Never had an expansion tank.
Never had any issues you speak of in 21 years.

Yes
Not all homes have them
In that case they have a Thermal Expansion Valve . I believe around 2000 all homes started using them here in the villages unless you have a tankless water heater. I was told by a local plumbing company here that it’s now Florida Code and all homes require a expansion tank.
So most homes north of 466 do not have expansion tanks. Up north we never had expansion tanks either.

BTW
Thermal expansion valves can fail and can raise the pressure in your pipes also

Or call Mike Scott Plumbing.

How did you know the Blatter was bad? I have a slight noise in the master bathroom when the water is running anywhere in the house. Dave