Home Improvement → [Plumbing] Pressure tank check valve: needed or not?

I am going to swap out my pressure tank for a larger unit. I have researched many differing opinions (with no general consensus) on using a check valve right before a pressure tank in addition to the check valve on the submersible pump.

Some argue that a second check valve at the tank can create water hammer down the road, or even contaminate the well, without the homeowner ever knowing anything is going on.

The other school of thought is that the second check valve takes some of the load off the check valve down at the pump, and helps to avoid strain and failures, as well as help diagnose issues as to in or out of a house.

What's the correct way to do this? Or is it really a personal preference with both pros and cons?

You'd be better off with the only one check at the tank. I think you said you changed out your old pump because the internal check failed. You could have put one at the tank and kept the pump if that was the case. I don't know about having 2 in series between the pump and tank. Why don't you call your well driller and just ask?

I could ask them actually. The check valve that failed last time was at the pump. I am not sure if there was one on the tank that was just removed actually.

I think with yours you can go either way. Normally, with a deep well, it is recommended to have one every 200'. I would probably leave it in unless it is creating water hammer.

Just called well driller. They put in a check valve at both places, and some along the way depending on well pipe depth. I will take their advice and keep the check valve there.

That answers your question. It's better to ask experts in the field.

Interestingly, they also recommended NOT to insert a dole valve when the tank is changed. They view the uplift given my situation as a nonissue, and agreed the lines need to be protected the most given my situation anyway. But they agreed the tank needs to be upgraded to get close to a minute runtime on the pump. That they were concerned about.

Did you ever measure how much was being pumped in those 28 seconds?

Not yet. Honestly, I'm upgrading to the wx-203 either way. My brand new T is a direct swap from the 202 to the 203 and it is the same size as the 202, just taller.

I plan to time it once it has been installed. As long as it's close to a minute, I'll be satisfied. I don't want to have to buy a new T given I just bought one. Plus the 203 is the easiest to swap given the identical circumference.