Tri Clamp or Threaded Ball Valves

[sndog]

I am working on ordering the parts to make my HVAC water distribution manifolds. They will be made out of stainless steel. a 1.5" ball valve into a 5 port manifold. 3 ports will have 1" stainless ball valves. One will be reduced down from 1" to 3/8" to allow a pressure gauge to be put into place, and the 5th with be capped as an extra if needed in the future.

I have two of these needed for my boat. Each will be feeding 3 HVAC units. worse case, 2 -24kBTU and 1 - 18k BTU unit. A single pump on each side, coming in from a sea chest on each side. With a variable speed pump pushing a maximum of 4700GPH to each manifold.

My question is would tri clamp fittings be acceptable, or stick to standard NPT fittings. Ball valves will be 3 pc units each. The output from the 1" will be 1" hose barbs going to flex tubing. And the 1.5" will have be the same with hose barbs.

The sea chests are stainless. Boat is steel.
Thank you as always in advance.

 

[Bmarler]

I think tri clamps would not be a good choice. Those are purpose built for easy tear down and cleaning. Stick with normal pipe fittings or pex manifolds or other fittings that won’t make a surveyor make a note to your insurance company.

 

[Shrew]

This seems largely over-designed.

What problems are you attempting to resolve here?

 

[sndog]

I think tri clamps would not be a good choice. Those are purpose built for easy tear down and cleaning. Stick with normal pipe fittings or pex manifolds or other fittings that won’t make a surveyor make a note to your insurance company.

Have you seen any PEX manifolds with 1" outputs? That would make life much easier.

 

[sndog]

This seems largely over-designed.

What problems are you attempting to resolve here?

Basically, I have 6 HVAC, self-contained, units. 3x 24kBTU; 3x 18kBTU. I have two pumps, each putting out about 4700GPH maximum from my sea-chests into a manifold for distribution to the HVAC units. Each output

Each manifold input, I want a ball valve on, as this is coming out of the sea-chest. Each manifold output I want a ball valve on to be able to turn the flow off I want to. And have one extra port per manifold. The pressure gauges on each are an easy way to identify any issues starting to crop up, intake having issues, pump losing power, or lines clogged.

 

[Bmarler]

this seems more like a specialty sort of installation. i haven't seen any pex manifolds in that type of configuration.
i would suggest having someone fab up a welded manifold in 316ss and use ball valves in npt and then pex adapters if that's what you want for tubing.
i have no idea if pex is a recommended material for raw water plumbing, but it seems like it would be pretty ideal as far as bulkiness goes.

 

[ksanders]

In addition you might consider Groco check valves.

If anything can suck back air it will.

 

[sndog]

this seems more like a specialty sort of installation. i haven't seen any pex manifolds in that type of configuration.
i would suggest having someone fab up a welded manifold in 316ss and use ball valves in npt and then pex adapters if that's what you want for tubing.
i have no idea if pex is a recommended material for raw water plumbing, but it seems like it would be pretty ideal as far as bulkiness goes.

I am looking at either having a manifold built, or use stainless T's to build one.

I have reinforced lines ran to the HVAC units already, so will just use a hose barb.

 

[bkcorwin]

I'd go stainless tees. It's not really that many ports and you could assemble it with a bunch of short nipples and Tees pretty simply. Then they make NPT to pex adapters that transition to pex.

As was mentioned, the tri clamp is great for easy cleaning in a food situation, but here has no real purpose.

 

[JMcJ]

I am interested in what you ascertain you ascertain the thread to be. The seacocks on Unicorn (1981) are Wilcox- Crittendon and at the outlet have a male thread over which a collar threads and allows a 90 deg elbow to pivot. It is a 1” hose fitting I want to remove to 3/4”. I don’t want to use a step down hose adapter because that actually results in a reduction to 1/2” id which is a significant flow reduction. I have considered joining the two hoses using JB Weld plastic binder but would prefer a direct to seacock connection.

 

[JMcJ]

Whoops, posted incorrectly. Sorry.

 

[Steve DAntonio]

I would absolutely avoid stainless steel for this application, even 316L. As robust as stainless is, for continuously immersed applications it is prone to crevice corrosion and leakage. I have lost count of the number of stainless raw water plumbing fittings I have seen corrode, leak and fail.

Bronze (not brass) would be one option, or even better, reinforced plastic like Nylon (Marelon and TruDesign components are two examples of reinforced plastic). Or FRP. There are off the shelf reinforced non metallic manifolds available.

More on stainless steel here https://stevedmarineconsulting.com/stainless-steel-miracle-metal/

Raw water plumbing for HVAC https://oceannavigator.com/article/ac-raw-water-failure-avoidance/

 

[mdstrum]

I like the manifold on my reverso oil change system...I just did quick check and sell sell just manifolds, maybe this is worth a look https://reversopumps.com/va-5/

 

[mdstrum]

also Mcmaster carr on this blocks that we used for fuel...maybe another option vs a bunch of T's https://www.mcmaster.com/products/manifolds/for-use-with~diesel-fuel-1/

 

[O C Diver]

Uncharacteristically for me, I would go with PVC well above the waterline. I used 1" PVC on Slow Hand for the raw water distribution to the AC units. The manifold was in a compartment, on the main floor, fastened to the floor. I used 1/4 turn PVC ball valves and standard PVC pipe fittings.

Once properly adjusted, you will probably never touch the valves again. If you want to change it, just buy all new and start over. You'll never have any kind of problem with corrosion. The PVC won't have a problem with Barnacle Buster or and other type of cleaner. And the 15 psi system pressure certainly isn't going to affect it. For a simple manifold that is connected with only hoses, I couldn't finf a logical reason not to use PVC.

Ted