Why do I keep cracking the ports on my multiport valve?

[1poolman1]

In my opinion, manufacturers should give torque specifications for all items requiring a torque to install.

The terms “hand tight”, “finger tight”, “Snug” etc. are vague and inexact.

I have used these terms and I will probably use these terms again because I don’t have torque specifications for most applications.

There is an art and a science to getting the correct torque even when you have a torque specification and a torque wrench.

Some people have a good understanding of these terms and a good feel for how tight to make different things from screws, bolts, nuts, fittings etc. and some people don’t.

Hayward, Pentair and Jandy do provide a few torque specifications for a few things, but for the most part, they do not provide torque specifications.

View attachment 478188

https://hayward-pool-assets.com/assets/documents/flowcontrol/pdf/iom/FLVPIOM.pdf

View attachment 478190

https://www.pentair.com/content/dam/extranet/nam/industrial-flow-technologies/flow/ift-asset-library/pool-spa/S285(10-15-04).pdf

View attachment 478191

https://www.jandy.com/-/media/zodiac/global/downloads/h/h0576700.pdf

Unless one actually worked with a (obsolete) SwimQuip DEP filter (the one in the diagram), you wouldn't realize how pointless those torque specs are. Once the large O ring between the halves relaxed and/or became misshapen torque was gone. In practice, though not recommended, usually only half the bolts were ever put back in after a tank was opened.

Torque settings have very little, if anything, to do with pipe fittings. "Hand-tight plus . . . " works for many/most applications. Another with regard to NPT fittings is "never less than three, never more than five" threads showing in a properly tightened pipe application. A good tech will find out what works for them and use it forever. They also know that a pipe fitting should not be tightened completely in. If it leaks, back it out and re-seal. That's why unions are so good to have. The type of thread sealant, which should always be used with NPT pipe, has a lot to do with it as well. If using Teflon tape, are you using the "good" stuff that meets MIL standards or the Home Depot special that is half the thickness.

High-temp pump unions are different as the threads are not tapered and they do get tightened until the O ring seals, not until the ring is flat. That allows for tightening at a future date as the O ring can harden from the environment and loosen with the vibration of a pump. Personally, I also use three or four wraps of Teflon on them as I don't like call backs for small drips.

 

[kakerlak]

Unless one actually worked with a (obsolete) SwimQuip DEP filter (the one in the diagram), you wouldn't realize how pointless those torque specs are. Once the large O ring between the halves relaxed and/or became misshapen torque was gone. In practice, though not recommended, usually only half the bolts were ever put back in after a tank was opened.

Torque settings have very little, if anything, to do with pipe fittings. "Hand-tight plus . . . " works for many/most applications. Another with regard to NPT fittings is "never less than three, never more than five" threads showing in a properly tightened pipe application. A good tech will find out what works for them and use it forever. They also know that a pipe fitting should not be tightened completely in. If it leaks, back it out and re-seal. That's why unions are so good to have. The type of thread sealant, which should always be used with NPT pipe, has a lot to do with it as well. If using Teflon tape, are you using the "good" stuff that meets MIL standards or the Home Depot special that is half the thickness.

High-temp pump unions are different as the threads are not tapered and they do get tightened until the O ring seals, not until the ring is flat. That allows for tightening at a future date as the O ring can harden from the environment and loosen with the vibration of a pump. Personally, I also use three or four wraps of Teflon on them as I don't like call backs for small drips.

I am far from an experienced plumber and barely know my way around this pool stuff, to boot. Do you think most of my problem was just the thread sealant I happened to choose? Only ended up with this stuff because I saw the brand referenced in a pool plumbing tips page somewhere and it advertised flexibility, weather resistance and being suitable for "all plastics." I'm really not exaggerating in saying that those pipes (gripped around the pipe itself like a screwdriver) smoothly turned in and felt just at the edge of starting to snug down. In googling the Permatex #2 that the sticker suggests I use, that seems to be silicone make-a-gasket stuff, rather than something being sold as thread sealant.

The Tru Blu stuff I used was pretty thick. I put it on both male and female sides of the joint, as its instructions said to do so for pipes over an inch in diameter.

Since I almost surely will need to buy another new multiport valve, what do you guys suggest I do? Wipe the existing threads clean and assemble with just whatever little bit of old sealer is left behind? Splice on new clean threaded ends and use a different sealant? Splice on those o-ring compression fittings instead?

 

[bradgray]

Since I almost surely will need to buy another new multiport valve, what do you guys suggest I do?

If we wanna throw mud and watch what sticks; Pentair's multiports include slip fittings. The lines attached to those are rarely serviced. We've glued/welded NPT fittings before when we knew we'd never need to remove them and didn't want to risk a leak. Caveat - this was always PVC to PVC. Perhaps others can confirm if Haywards hybrid plastic will bond using a typical pvc weld. If so, you could theoretically be even more gentle with the insertion because you're not relying on threads to seal the connection.

I would never do this at a clients home, but I'd probably be willing to gamble $200 as a last resort at my own place.

Wipe the existing threads clean and assemble with just whatever little bit of old sealer is left behind?

Sounds like the definition of insanity, no?

Splice on new clean threaded ends and use a different sealant?

Sealant is two-edged sword. It seals, but it also lubricates and makes it far easier to over-tighten by mistake. I personally use a lot of Rectorseal T Plus 2. Never had the stuff leak, but I've cracked female fittings before. Learned over time when it was "good enough".

Splice on those o-ring compression fittings instead?

This will guarantee you don't apply any outward pressures to the multiport. But you have to make sure the union rings won't make contact with each other given how close the sockets are. Don't get big honkers.

My final disclaimer is that I don't have a single Hayward multiport at any account. The few Haywards we have are all cartridge. All of the advice above is predicated on adjacent observations. And on that note, Google images shows most homeowners using NPT fittings so I'm not so sure we can lay all the blame there.

 

[kakerlak]

If we wanna throw mud and watch what sticks; Pentair's multiports include slip fittings. The lines attached to those are rarely serviced. We've glued/welded NPT fittings before when we knew we'd never need to remove them and didn't want to risk a leak. Caveat - this was always PVC to PVC. Perhaps others can confirm if Haywards hybrid plastic will bond using a typical pvc weld. If so, you could theoretically be even more gentle with the insertion because you're not relying on threads to seal the connection.

I would never do this at a clients home, but I'd probably be willing to gamble $200 as a last resort at my own place.

Sounds like the definition of insanity, no?

Sealant is two-edged sword. It seals, but it also lubricates and makes it far easier to over-tighten by mistake. I personally use a lot of Rectorseal T Plus 2. Never had the stuff leak, but I've cracked female fittings before. Learned over time when it was "good enough".

This will guarantee you don't apply any outward pressures to the multiport. But you have to make sure the union rings won't make contact with each other given how close the sockets are. Don't get big honkers.

My final disclaimer is that I don't have a single Hayward multiport at any account. The few Haywards we have are all cartridge. All of the advice above is predicated on adjacent observations. And on that note, Google images shows most homeowners using NPT fittings so I'm not so sure we can lay all the blame there.

Thanks for taking the time to offer such a thorough reply! I guess I'm pretty well stuck using these Hayward valves unless I change over the filter, too?