Fitting -> submersible well pump, tape or dope?

[Whereismyhat]

So after way more reading than I originally intended..... (There's seemingly an inexhaustible wealth of knowledge on this forum, which accounts for every corner case disaster, most that I never even considered were possibilities.)

I think I'm getting a bit paranoid now that I'm preparing what I need to prepare for. I have seen a couple of posts mentioning concerning torque and the tightness of PVC fittings attached to the head of the submersible pump.

I saw the bowls of a Goulds 25HP 150H series pump come unscrewed from rapid cycling....the 4" drop pipe did not though. It something like a 9 or 10 stage pump, and it was starting approximately every 20 seconds and running about 15 seconds......They had a waterlogged 5000 gallon Hydro tank, with no working air compressor. It just hammered itself apart, until it got so long, it pulled one of the splices apart. Luckily it didn't come all the way unscrewed.

Small pumps can come unscrewed as well. That is why I quit using threaded plastic couplings and switched to metal couplings. When you tighten PVC pipe into metal couplings without any Teflon or dope, it will pop 2 or 3 times when it is tight. It also has to pop a few times to get it unscrewed, which is why I believe it is less likely to come unscrewed from cycling.

Pipe wrap and sealant for stainless fittings
First time well pumper - pressure issue
Schedule 80 deep well pump barb?
Submersible Pump Recommendation

Unanimously, everyone seems to recommend brass or stainless steel fittings, and that is what I have planned with my pump install. My previous pump was schedule 80 with PVC fittings and it was really tightened really well to the discharge head. It lasted 20 years without seemingly shifting even a little from the original thread position. Though, I'm not keen on testing my luck again given the quoted posts.

My new 1HP pump is like my old one, and has a nylon discharge head. I am planning to use 1 1/4 poly pipe 160 PSI with 1 1/4 stainless steel barb fittings.

I've watched various videos and most people seem to use only pipe dope/sealant on the barb fitting into the top of the submersible well pump. I was wondering is there a reason for this? Is this the recommendation to use dope instead of tape? How much do I have to worry about overtightening and breaking threads?

 

[Valveman]

With a SS fitting and a Nylon head too much Teflon will act like a wedge and cause the head to split. Teflon paste will make it too slick and the pipe can tighten in the Nylon head too far and split the head or hold the check valve down. I would just run it dry and tighten the fitting well. But if you want to use something try Rectorseal, as it is not as slick and will set up and get hard in a short time, which helps prevent unscrewing.

However, I have welded steel pipe to the steel couplings and the pump still came unscrewed when there was too much cycling on and off. Eliminate repetitive cycling and unscrewing the drop pipe becomes a non-issue.

 

[Sponsor]

 

[Whereismyhat]

That's rector seal 5 right?

 

[Valveman]

That's rector seal 5 right?

Yep.

 

[Valveman]

There is a fine line between getting it tight enough to not come unscrewed, and so tight it will never come unscrewed. One of my favorite sayings before I start cussing is "somebody thought they would never have to take this apart again". Lol!

 

[Whereismyhat]

Thanks! I assume the same goes for the fitting attaching the poly to the pitless? I should just use rector seal 5?

Also, do I need to do anything to prep my pitless to be installed back in? There's a bit of grim I figured I would carefully wash off without touching the o-ring.

 

[Reach4]

You should replace the o-ring. Can you identify the pitless?

The barbed fitting under the pitless, that the drop pipe hangs from, should be an extra long insert fitting. Use 3 worm-gear clamps with the worms not adjacent.

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[Whereismyhat]

It's an extra long barb like in the first post. If I replace o-ring, should I scrub off the rust or use rust remover?

My pitless has the name williams on the side of it, but it just looks like a generic pitless..., nothing special about its style? Could I just get a off the shelf pitness and use the new drop in half?

 

[Reach4]

If you cannot ID the pitless to go get a replacement o-ring, see https://terrylove.com/forums/index.php?threads/leaky-pitless-adapter.90975/ including #11. I expect prices have risen.

That said, many reuse the o-ring. Lube with silicone grease whether new or reused. I like Molykote 111 for seals that do not deal with movement once installed.
As far as the rust, I don't think the pitless is rusting. I think that is just an iron deposit. You could probe around the pitless with a magnet to see that nothing attracts a magnet. On flat surfaces, I will sometimes use a single edge razor blade... never did that on a pitless however.

So I am not sure if scrubbing would be right, or you will want a paste of Iron Out.

 

[Whereismyhat]

Five minutes with some warm water and paper towels later...

Is there any other sign besides leaking which would indicate necessary o-ring replacement? My o-ring looks ok.

My plan is to use rector seal 5 with the barb fitting and the pitless adapter like @Valveman suggested for the barb and the pump head. Yeah, I know i need a few SS band clamps for the long fitting and the pipe.

 

[Valveman]

The o-ring looks OK. But you can find one in an o-ring kit. Just use one that has to be stretched ever so slightly to fit.