Wellmate pressure tank - QC fitting

[BostonGuido]

I'm replacing a Wellmate pressure tank with an identical one (the bag leaked) and the new tank did not come with the packet of lube for the QC fitting (O-ring). Anyone know what type of lube should be used? Would rather just use the right thing if I have it, or buy locally, than wait for a replacement (no distributor nearby) in the mail.

 

[Reach4]

Locally, you can probably find silicone 0.5 oz
https://www.danco.com/product/0-5-oz-silicone-faucet-grease/ Danco 88693 meets NSF 61 (water)

If ordering, I would go for Molykote 111. Molykote 111 is not as widely available, but comes in a 5.3 ounce tube instead of 0.5 ounce. That is for people who expect to do a lot more lubing of such static seals.

I would not have chosen the Wellmate pressure tank. Tanks with a diaphragm are more durable. However if I had a Wellmate, I would consider replacing the bladder.

See https://www.aquascience.net/products/pumps-tanks-well-components/wellmate-pressure-tanks "Air Cell Replacement Kits" about midway down the page. Not easy to replace, but should be easier than replacing a whole tank. Also, consider the one-size-up bladder, which may or may not last longer.


I am not a pro.

 

[Sponsor]

 

[BostonGuido]

My concern is the material of the oring and of the plastic fittings. Some greases swell some oring materials and break down the plastic of fittings. There are many oring materials - FKM, NBR, EPDM just to name a few. There are also many potable water rated plastics - CPVC, PVC, ... It's not a trivial decision and if the oring gets swelled and degrades over time there will be a flood. Have contactedPentair but no response yet.

 

[Reach4]

See https://www.allorings.com/o-ring-compatibility and scroll/search down to SILICONE GREASES.

 

[BostonGuido]

See https://www.allorings.com/o-ring-compatibility and scroll/search down to SILICONE GREASES.

Pretty convincing - thanks, Reach4. So unless it's a silicone O-ring I should be good. And in my experience, silicone O-rings are milky colored, and this one is black, so pretty sure I'm good. Appreciate the assist.

 

[Valveman]

You seem to be very technically minded and trying to prevent problems. I commend you for that. Maybe you should go one step further back and figure out what caused "the bag to leak" in the tank that started the problem. I prefer diaphragm tanks to bladder (bag) tanks as the moving element doesn't touch the sides or cause any wrinkling during the pump cycling process. Then going even one step further back yet is to realize pump cycling is what caused all the problems to begin with and figure out how to eliminate or greatly reduce the cycling.