White-lined Fiberglass or Black Armaflex Insulation for Near-Boiler Piping?

D107

Hoping to finally get this done on my 1.5year old hot water boiler. 1.25" steel and 3/4"copper. Maybe 1" thick insulation. Seems like the Armaflex is easier to install though maybe slightly less effective(?)

EBEBRATT-Ed

Armaflex does not work well with heat, it will dry out and crack

Joseph_4

Almost no R value with Armaflex , if u are going to spend the time doing it..the white fiberglass is real insulation. Home contractors use Armaflex cuz its inexpensive.

D107

FYI this is hot water system.

ChrisJ

Joseph_4 said:

Almost no R value with Armaflex , if u are going to spend the time doing it..the white fiberglass is real insulation. Home contractors use Armaflex cuz its inexpensive.

I'm over here trying to figure out what armaflex is cheap..... The stuff I've used sure wasn't. 

It appears 3/4" thick Armaflex has an R value of 6+-.  This is very similar to 1" thick fiberglass pipe insulation.

I've used it with recirc hot water and refrigeration stuff but wouldn't use it with steam.

bburd

The maximum service temperature for Armaflex is 220°F. While that is just above the 215°F of the low pressure steam in most home heating systems,  foam insulation is likely to degrade prematurely when repeatedly exposed to that amount of heat.

I have never seen that type of insulation on an engineered steam system. The industry standard for steam is fiberglass.

Joseph_4

in my plumbIng supply armacell and armaflex are 6 foot lengths,
the fiberglass is at most 3 feet a length and its more than double the cost easily. could you tell me where that it says its a 6 plus R value. It would be helpful for me to show customers.
Thanks
Joe

SuperTech

I've seen armaflex used in plenty of homes on hydronic systems without drying out or cracking. I believe its only when armaflex is left out in direct sunlight is when it has a tendency to deteriorate. Thankfully I have never seen it used on steam, fiberglass is the only way to go with steam. I'm sure the armaflex is better than nothing. I've also heard that bare copper pipe doesn't lose much heat, so unless the pipes are going to an area where freezing temperatures are a concern insulation isn't totally necessary.  

ChrisJ

Joseph_4 said:

in my plumbIng supply armacell and armaflex are 6 foot lengths, the fiberglass is at most 3 feet a length and its more than double the cost easily. could you tell me where that it says its a 6 plus R value. It would be helpful for me to show customers. Thanks Joe

I had found it on Armaflex's website last night.  Google Armaflex R value.

Yes it does come in 6 foot lengths but look at the price of the 3/4" wall and 1" wall Armaflex.  

D107

For my hot water system I think the specific products would be either their AP Armaflex Black Lap Seal or the Armaflex Insul-Lock Peel & Seal. Not sure what the difference is. Plus I'd have to get some of their fabricated fittings. However everything seems sized for copper or IPS. What about steel 1.25"? Can I stretch the 1.25" copper armaflex around it?

Paul Pollets

I use ImcoLok neoprene for HW systems. It comes in sizes for both copper and steel pipe. The copper sizes won't fit on steel pipe. 1/2" or 3/4" wall thickness. It is split with a self sealing tape. I use a miter box to do the fittings. Fiberglass is for steam systems.

https://www.ferguson.com/product/nomaco-insulation-imcolock-34-x-12-in-44-pack-pipe-insulation-self-sealing-tube-n6il048068/_/R-176169

D107

@Paul Pollets thanks but just found out on Nomaco's site:

Nomaco No Longer Manufactures or Supplies Pipe Insulation
On January 9, 2017, Nomaco and Armacell announced Armacell’s purchase of Nomaco’s insulation division. All insulation brands formerly produced by Nomaco are now part of the Armacell offering. Nomaco continues to develop and manufacture custom engineered foam products and components for a wide range of markets including construction, home furnishings, packaging, fitness & recreation and more.

hot_rod

If you buy a quality brand with the temperature rating the black stuff should work. We have used the high temp stuff on solar thermal for years. Some brands actually made a solar specific version, able to handle intermittent 300° spikes.
We sold the pre-insulated SS solar flex, 350° fluid temperature rated. I have some 10 year old stuff on my home, keep the sun and birds off it If it is outside it needs UV protection, of course.

Take a sniff, the stronger the smell, the more EPDM, the better the grade of insulation, is how one manufacturer explained it to me.
K-Flex is one of the good brands also.

I like the stuff with the peel and stick seam AND the flap that goes across the seam for a second seal. Buy one of the miter devices with a knife to make nice ells and tees.

You can always add the aluminum wrap and fitting covers if you want an even more durable cover.

Paul Pollets

If you have a local Ferguson's, give them a call. Or Supplyhouse.com sells it.

ChrisJ

hot_rod said:

If you buy a quality brand with the temperature rating the black stuff should work. We have used the high temp stuff on solar thermal for years. Some brands actually made a solar specific version, able to handle intermittent 300° spikes.
We sold the pre-insulated SS solar flex, 350° fluid temperature rated. I have some 10 year old stuff on my home, keep the sun and birds off it If it is outside it needs UV protection, of course.

Take a sniff, the stronger the smell, the more EPDM, the better the grade of insulation, is how one manufacturer explained it to me.
K-Flex is one of the good brands also.

I like the stuff with the peel and stick seam AND the flap that goes across the seam for a second seal. Buy one of the miter devices with a knife to make nice ells and tees.

You can always add the aluminum wrap and fitting covers if you want an even more durable cover.

I bought all of mine from McMaster and I don't recall what brand it was, but it stunk bad enough it made my whole basement smell when I brought it down there. 3/4" thick for 7/8" OD pipe makes for a lot of rubber.

I want to say it was actual ArmaFlex but I could be wrong. That writing on your K-Flex looks identical to mine, color, font etc.