You are here:

Plumbing in the Home/Reducing size of gas piping, what is the fitting?


Hi Dana,

In black iron piping, how does one correctly reduce the size of a pipe?  Is the fitting called a reducing coupling?  I have also heard of bushings but those are not recommended as I understand.

Also, I can't find on homedepot or lowes, a reducing coupling that would take 1" down to 1/2".  They do have 1" to 3/4", then 3/4" to 1/2".  Have you heard of any reducers to take 1" to 1/2"?


Hi Thomas,
On the surface, that seems an odd set up if you have to reduce a 1 inch pipe down to half-inch. The proper fitting is called a "Bell reducer". If you cannot find one in black iron pipe, a galvanize fitting will do.

If this is supposed to be a branch line, then a reducing tee is the proper fitting. Plumbing fittings are "called" in the following format: Run X Run X Branch.  Tee fittings come in many configurations; 1 X 1 X 1/2, 1 X 3/4 X 1 Etc.

Having said all of that, the gas piping system is a tricky beast. It must be correctly sized to avoid starving the appliance load at the end of the line of any branch. The consequences of improperly sizing a water piping system are just poor performance and low water flow at the end. In the case of a gas piping system, starving the load will cause it to malfunction and possibly create excessive carbon monoxide. CO is a silent killer. Make sure your know it you're doing before you just willy-nilly alter the gas piping system.
Good Luck,

Plumbing in the Home

All Answers

Answers by Expert:

Ask Experts


Dana Bostick


Pretty much any residential plumbing questions. For "item specific" details such as a specific model of fixture, I will need to research and there may not be any useful information available. Note: I live and work in Southern California. We do not, as a rule, use hot water or steam heating systems, oil fired boilers or private water wells so my knowledge in those areas is pretty limited. There are others here on AllExerts that can probably answer those questions better.


Retired, Licensed General Contractor with Plumbing license. Active Home Inspector, Litigation Consultant and Infrared Thermographer, Online Marketing specialist.

Publications "Rain Maker" as "Inspector Dana", about making money online.

30+ years in the building trades, Licensed General Contractor (Retired), Certified Infrared Thermographer Internet Entrepreneur, Amazon & eBay Merchant (deals-by-dana)

Awards and Honors
Listed FHA Fee Inspector, FHA 203(k)Consultant, HUD Mobile Home Inspector

Past/Present Clients
Home buyers, sellers and owners, Investors, Commercial roofing companies (infrared roof scans for moisture intrusion, Litigation Consulting for "Slumlord" laws in SoCal

©2017 All rights reserved.