Bleed valves or no bleed valves on baseboard 90 fittings?

JohnJr

I'm running a primary loop with 3/4" oxygen barrier pex C running to 12 individual slantfin fine line 30 hot water baseboards. The heating element in each one is 3/4" copper with one side being a sweat cup. Luckily, there is enough length on the side that has the wider diameter end, and my plan is to cut the cupped end off each one and fit a sharkbite 90 elbow between the Pex C and 3/4" copper. My main zone panel has an air eliminator located not too far above the expansion tank. Should I go with 1 sharkbite 90 that has a drain/vent valve on each baseboard or just rely on the main air eliminator on the primary zone panel and use regular sharkbite 90's instead?

STEVEusaPA

How about no shark bites.
If your near boiler piping is of the pumping away model, and you have a micro bubble air eliminator, and you can isolate each zone, you can eliminate all the air in the basement, purge it once and probably never have to do it again.

Ironman

I wouldn't recommend using Sharkebites on a hydronic system. They allow too much O2 ingress.

hot_rod

unless you have a lot of ups and owns in the piping, I would skip bleeder ells. and the grip type fittings

GW

One pipe and Pex? Doesn’t sound good, too many bumps and sags 

NoelAnderson

On Ironman's comment about Sharkebites allowing too much O2 ingress, will the new copper crimp fittings from Viega and Nibco also allow too much O2 ingress? They seal the same way as a Sharkbite with an O-ring.

mattmia2

That tube in fin tube baseboard is paper thin. I would only connect to it with sweat fitting. Mechanical fittings won't go well.

STEVEusaPA

mattmia2 said:

That tube in fin tube baseboard is paper thin. I would only connect to it with sweat fitting. Mechanical fittings won't go well.

They make an insert for the fin tube so you can crimp.

Ironman

NoelAnderson said:

On Ironman's comment about Sharkebites allowing too much O2 ingress, will the new copper crimp fittings from Viega and Nibco also allow too much O2 ingress? They seal the same way as a Sharkbite with an O-ring.

No they won’t allow O2 ingress. The O ring is pressed from a tool that provides up to 30k lbs pressure at the jaws; the shark bite O ring is not pressed.

EdTheHeaterMan

@JohnJr is doing a DYI system install. I'm thinking maybe giving advice other than Call a Pro might not get understood properly. Professionals take for granted that everyone knows what we are talking about with some of the more intricate processes. If John asked about an oil burner nozzle, you can be sure that there would be at least 4 posts telling him to Call a Pro to get a combustion test for properly adjusting the burner. Remember that Navien boiler he is installing needs a combustion analyser to properly set it up. I believe that some things are DYI for many homeowners, but the research needs to be complete and not just advice from a site like this.

Buy a book on how to connect pipes with solder and a torch. Read up on piping design. Rent a crimp tool for the weekend and use fittings a professional would use. And don't do this.
If you need a Pro later down the line, you will pay dearly for the needed repairs. If I walked in on that, I would Quote on a complete tear out and re-do. That is usually more expensive than doing it right the first time.

When you kick me out because my price is too high, I'm happy to leave you with your problems. I'm not saying that you are going to do something as bad as the picture, I just want you to know that you should make the job look and operate the way a professional would do it. If you are confident that you can do that, then Go For It! But asking about using shark bite as something other than a temporary repair until you have time to get it done right, well that says something about the quality of the work you would be satisfied with. I certainly would not want to come to your job for a repair in the future.

Just Sayin'

Mr. Ed

NoelAnderson

Thanks for the reply Ironman. I was a little worried about your first comment with O2 ingress. I just finished my first job with a manual copper press tool and have started doing a second job now. I am surprised at how fast it increased my speed with the copper work. Unfortunately I cant justify the price for a power copper press right now, and the manual press tool gives me a good work out.

hot_rod

O2 ingress has more to do with the type of material. We all learned that EPDM, in radiant tubing PB non barrier pex, rubber tube, does allow some O2 ingress.

I know press fittings do not seal when the o-ring is left out So that ring is somewhat exposed, crimped or not.o

O2 ingress happens around the o-rings on valve stem packing, pump seals, really any moving or non moving "rubber" connection that does not have an O2 barrier material.

That would be an interesting study, how much O2 ingress in fittings, any fitting that has an o ring that is made with O2 permeable materials. I imagine the actual area ratio comes into play, as would operating temperatures.

JohnJr

All of your comments are well appreciated and the topic of sharkbite fittings are very well opinionated, but until I can see some legitimate proof that they should not be used on hot water baseboard connections then prove me wrong. It's ironic however that my pre assembled zone panel has a 1/2" shark bite shortly from the expansion tank and 1" sharkbite connections for the return and supply on the primary loop. You'd think Hydro Smart techs would know their stuff?

hot_rod

JohnJr said:

All of your comments are well appreciated and the topic of sharkbite fittings are very well opinionated, but until I can see some legitimate proof that they should not be used on hot water baseboard connections then prove me wrong. It's ironic however that my pre assembled zone panel has a 1/2" shark bite shortly from the expansion tank and 1" sharkbite connections for the return and supply on the primary loop. You'd think Hydro Smart techs would know their stuff?

You are correct, it is mostly personal opinion. If the fitting is tested and listed for the fluid, temperature and pressure, take your pick.

Plenty of boiler fitters use only threaded pipe. ask the steam guys which pipe and fitting is best:)
Others swear by sweat joints, not trusting o ring seals, they are reusable and easier to repair a leak compared to thread and press.
Plenty of press fans, labor hours is the main selling feature.
Pex, expand or crimp
PPR
welded steel or stainless, all viable products