What is best PEX coupling for water pump?

[Bexar]

I am experiencing a slow loosening of the pex to water pump couplings on both sides of my water pump and any place else they are used. Happens over about a week of traveling. I have been tightening these by hand but extremely tightly until they won’t budge since they are plastic, what they attach to is plastic and there is no sure way to grip them with a wrench outside of channel locks. I could convert the couplings to brass which I can wrench tightly but before proceeding with this change I’m interested in the group ‘s experience. Thanks

[skyguyscott]

I use flexible hose attached to the water pump with hose clamps. This has the added benefit of reducing pump noise. I suspect the pump vibrations are working loose the screw connections on the rigid pex. Flexible hose and hose clamps will fix this, however, I note that I really have to tighten those hose clamps on super tight with a ratcheted nut driver. A screwdriver won't do.

[ROBERTSUNRUS]

Hi, my water pump sits different than yours; I use 90 degree fittings to my pump / accumulator assembly. I also made my own flex hoses. Hand tight and never come loose.


These pictures were taken before I installed my accumulator.

[mimiandrews]

You can find a "silencing kit" on Amazon that contains two flex hoses with fittings. They isolate vibrations from the pump so you hear only the pump and not its vibrations transmitted to the PEX. They should help keep the fittings tight for the same reason.

[RandyNH]

In almost all installation paperwork for these pumps, it cautions against using hard connections to the pump. I would remove them and install braided lines as a go between.

Example

Big box store has the hoses in the plumbing - washing machine hoses area

[Fred L]

subscribing.

[vintagemotor]

I have removed all of the hand screw fittings and applied a thin film of teflon tape, acts 2 ways as a leak and loosening prevention.

[GM Airstream]

Indeed... go get a pex ring cutter... cut the pex tubing off just outside the fitting... and snap the ring to save the T and the L... if they are brass fittings... you can take the fiber imbeded hose as shown in the other picture and use a 1/4 in wide hose clamp... over the center of the brass pex fitting... if they are plastic.. change 'em out while your their... with brass ones.. (big box store has the 1/2 in brass in sharkbite works great.. )
and the hose will take some of the vibration out of the pump and PEX...

You might want to get some new seals for the screw on fitting.. (or go get new ones at the box store... sharkbite has them...) as you probably have squeezed them well trying to keep them from dripping... I would try and make a 6 to 10 inch loop like the other gent did in his pix... on both sides... one after the filter to pex and one from the pump to PEX. It should take care of any vibration as well as not being pulsing at the tap... the hose acts like a accumulator kinda thing...

Never never have a pump wired directly to stiff tubing... they need to move around as they work... else you will break something of a leak..

Good luck G.M>

[tjdonahoe]

Originally Posted by Bexar

I am experiencing a slow loosening of the pex to water pump couplings on both sides of my water pump and any place else they are used. Happens over about a week of traveling. I have been tightening these by hand but extremely tightly until they won’t budge since they are plastic, what they attach to is plastic and there is no sure way to grip them with a wrench outside of channel locks. I could convert the couplings to brass which I can wrench tightly but before proceeding with this change I’m interested in the group ‘s experience. Thanks

Attachment 307346

You need flex hose on each side....for vibration...

[Leadvox]

There are some great video tutorials on this. They consensus is flexible tubing, with a full loop attached to the pump to reduce noise, like many of the rivet masters have already said.

[rmkrum]

I look at the "wings" on some of the fittings, and think: Tiny drilled hole, and safety wire, properly routed and secured...will stop the fittings from backing off...aircraft style.

[tjdonahoe]

Originally Posted by Bexar

I am experiencing a slow loosening of the pex to water pump couplings on both sides of my water pump and any place else they are used. Happens over about a week of traveling. I have been tightening these by hand but extremely tightly until they won’t budge since they are plastic, what they attach to is plastic and there is no sure way to grip them with a wrench outside of channel locks. I could convert the couplings to brass which I can wrench tightly but before proceeding with this change I’m interested in the group ‘s experience. Thanks

Attachment 307346

You need flex hose on each side....for vibration...

[Dingo Girl]

The hoses at the big box store that I saw all had a smaller inner diameter than the ones for RV use.
I don't know if it would matter to the pump or not.
I put the RV type on mine.

[waninae39]

DONT do it by hand
get the correct crimp tool. if not , it may be too tight and/or leak

they are NOT expensive at most big box stores

this is what my water filter with bypass looks like