How to insulate steam pipe elbows?

johnbk

I’m installing 1” thick fiberglass insulation tubes onto the horizontal 2” main steam pipes, as well as the smaller pipes that branch off. But how do you insulate the elbows? It’s a one pipe system.

FriendlyFred

If you're using PVC jacketed insulation and want your elbows to match, take a look at the type of products offered here: http://www.buyinsulationproductstore.com/pvc-90-deg-elbow-cover/

For 2" pipe and 1" insulation, the chart recommends a #11, which comes out to $2.19 per each. Comes with a fiberglass insert, wrap around the elbow and seal the PVC jacket around it, overlapping with your straight pipe insulation.

KC_Jones

What would you rather spend money or time?
If money then buy the PVC elbows.
If time you can use the mitered corner technique. See this thread.
https://forum.heatinghelp.com/discussion/151757/insulation-pics-using-mitered-joint-technique#latest

gerry gill

We use either high temp cement, wrapped, and coated with childers mastic, or lately the guys are buying bigger insulation and mitering the corners and carving out some of the fiberglass.

EBEBRATT-Ed

for heating the pvc covers are but on with white barbed thumbtacks available at your insulation supplier.

Cutting, coping and mitering are fine if you want to keep the cost down but it will take some practice and probably waste a little material.

It may boil down to how many fittings you have to cover. If only a few buy the pvc covers. If a lot of fittings you may want to cut and miter.

For me it's covers

MilanD

https://forum.heatinghelp.com/discussion/132995/what-type-of-pipe-insulation-should-be-used-on-the-near-boiler-piping

AnthraciteEnergetics

For my own house I cut strips of mineral wool and wrapped them with high-grade duct tape. Not pretty (use white to match the pipe), but it can be made surprisingly neat after you develop the technique.

New England SteamWorks

If you haven't purchased already and are doing it yourself, I would go with 1-1/2" insulation. Makes an appreciable difference, and the cost to efficient ratio without labor cost is awesome!

Johnbneal

It's great to see the photos of all the nice insulation detailing! One suggestion I would have is to bump up the insulation thickness. For a point of reference the energy code here in California (yes we have steam!) requires the following:
201-250 degree pipes (steam)
2.5" thick insulation on pipes <4" diameter
3" thick insulation on pipes 4" diameter and greater
141-200 degree pipes (condensate)
1.5" thick insulation on pipes <1.5" diameter
2" thick insulation on pipes 1.5" diameter and greater

hot_rod

If you want simple and pretty, buy more $$... I have used this Techlite product on a few jobs that I wanted a unique look. I used red and yellow and other colors.

They have preformed shells for ells and tees and the glossy PVC covers for fittings in matching colors.

EBEBRATT-Ed

The energy code in CA is fine but put 2.5 in wall on 2" pipe and you now need room for a 7 1/2" diameter pipe. In most existing jobs that will not happen.

The insulation thickness is a case of diminishing returns. Every inch of insulation you buy costs more money. After the first inch the insulating value of each inch decreases as the thickness increases.

Most old jobs would do well to have 1" or 1 1/2" wall a lot better than bare pipe

fixitguy

I always use as thick insulation as possible and I insulate the returns. No need to heat the basement. For the ell's and tee's I use 3" PVC vent fittings that I split on the bandsaw, pack with fibreglass and hold together with zipties.