What escutcheon size for 1 3/4" OD pipe? IPS confusion abounds

Motorapido · January 12

Help clear my confusion on the size of steam riser pipe escutcheon I need to order for risers measuring 1 3/4" OD. I'm not clear on the difference between IPS and nominal sizing. For instance, an amazon listing shows the following:
Floor and Ceiling Plate Split Flange, Fits 1-1/2 Inch IPS Galvanized Pipe or 2 Inch Copper Pipe.
What do I look for in product descriptions that will confirm that the flange escutcheon will be a nice, very close fit to the 1 3/4" OD of my steam risers?

JUGHNE · January 12

Go to a big box or plumbing hardware store, pick up a 1 1/2" nipple, go to the section that might have the flanges. See how they fit.....maybe even buy them there while they are still in business.... before all the stores are crushed by Amazon.

Motorapido · January 12

Home Cheapo and Blowes were very limited in their selection. They had many tiny escutcheons in the tub/sink/toilet plumbing section, but in the iron pipe aisle, all they had in a larger size are marked as 2 inch, and they show way too much slop between the ID of the escutcheon and the OD of the pipe. When I look online, I see references to IPS sizes and to iron versus copper pipe. Very confusing. I'm ordering a boatload of them (cleaning up and preparing a rental property for sale and you gotta have pretty pipe escutcheons everywhere, right?) and I don't want to order the wrong size.

Jamie Hall · January 13

1 3/4 inch does not correspond to any iron pipe size. 1 1/2 inch iron is 1.900 inches in diameter. 1 1/4 is 1.690.

Youngplumber · January 13

For copper add 1/8 to the nominal pipe size that's your od. There are many charts available online to look up iron pipe size od. For iron pipe size 1-1/4" you should be able to wrap your thumb and index finger around and have them touch but not by much. 1-1/2" won't quite touch. 2" won't even be close.

EBEBRATT-Ed · January 13

@Motorapido

for 1 1/4", 1 1/2" and 2" the OD is "about" a 1/4" larger than the nominal size. The nominal size is "about" the inside diameter. There are plenty of charts you can download

EdTheHeaterMan · January 13

Jamie Hall said:
1 3/4 inch does not correspond to any iron pipe size. 1 1/2 inch iron is 1.900 inches in diameter. 1 1/4 is 1.690.

That depends on how many coats of paint are on the pipe. If it has been there long enough that 1-3/4 pipe might only be a 1/2" riser LOL

Order 1-1/4 and 1-1/2 from amazon and return the one(s) you don't use. Also, check out Supplyhouse.com They have a liberal return policy. (not a Democratic Liberal... Just Liberal the way we used to mean it)

Motorapido · January 13

EdTheHeaterMan said:

Jamie Hall said:
1 3/4 inch does not correspond to any iron pipe size. 1 1/2 inch iron is 1.900 inches in diameter. 1 1/4 is 1.690.
So to put the question another way, for one-pipe steam, is the most frequently occurring OD of risers to radiators 1.90 or 1.69? My tape measure informed my lousy eyesight that the riser pipe measures 1.75. I'll guess that the pipe is then 1 1/4 IPS with a true OD of 1.690. Think that's correct?

Jamie Hall · January 13

Probably is. However, one simply can't say "the most common pipe size" for one pipe steam. The better installers used what was needed. Others used what was on the truck (or wagon!).