FHB Logo Facebook LinkedIn Email Pinterest Twitter X Instagram Tiktok YouTube Plus Icon Close Icon Navigation Search Icon Navigation Search Icon Arrow Down Icon Video Guide Icon Article Guide Icon Modal Close Icon Guide Search Icon Skip to content
Subscribe
Log In
  • How-To
  • Design
  • Tools & Materials
  • Restoration
  • Videos
  • Blogs
  • Forum
  • Magazine
  • Members
  • FHB House
  • Podcast
Log In

Discussion Forum

Discussion Forum

cutting into a gas line

Rich | Posted in General Discussion on December 29, 2007 02:03am

I want to break into a natural gas line, black pipe, to add a valve.  I’ll valve it off at the meter and turn the stove off to relieve the pressure in the pipe.  Is is safe to then cut into the pipe with a sawsall?  Could what ever gas is left lingering in the pipe be explosive from the sparks of cutting the pipe?

Reply
  • X
  • facebook
  • linkedin
  • pinterest
  • email
  • add to favorites Log in or Sign up to save your favorite articles

Replies

  1. sledgehammer | Dec 29, 2007 02:06am | #1

    Use a pipe cutter. Vibrating a gas line with a sawzall is never good for the fittings.

    1. Rich | Dec 29, 2007 02:12am | #5

      Is that like a tubing cutter on steroids?  It's kind of a tight spot, close to a joist.

  2. JHOLE | Dec 29, 2007 02:09am | #2

    I use a angle grinder to stop the vibration - FWIW.

    But then I use a propane torch to light cigarettes too.

     

    Remodeling Contractor just on the other side of the Glass City

  3. Dave45 | Dec 29, 2007 02:11am | #3

    If you shut the gas off at the meter and disconnect it at the stove, you should be able to work on the line safely.

    I question your use of a sawzall, however.  How do you plan to make up the line after you hack it off?

    1. Rich | Dec 29, 2007 02:14am | #6

      I plan to unthread each end of the cut pipe and thread in shorter lengthes joined together with a union.

      1. Dave45 | Dec 29, 2007 02:21am | #7

        Ok, that should work - although you'll probably need at least one "custom" length threaded nipple.

        I would still pass on the sawzall though.  They can vibrate things pretty badly and you may cause problems in other joints.  A hacksaw would be better if you have room to use it.

        1. Rich | Dec 29, 2007 04:14am | #8

          hacksaw it is.  Thanks.

  4. User avater
    davidhawks | Dec 29, 2007 02:11am | #4

    How you planning to tie-in?  Recip. saw doesn't make a very user friendly cut.

    Live in the solution, not the problem.
  5. DonK | Dec 29, 2007 05:13am | #9

    Rich, you might want to double check if the union's a legal way to go. One area I was in would only allow one union in a pipe run, and that can get tricky. OTOH, if it's not going to be inspected, might not be an issue either.

    Don K.

    EJG Homes   Renovations - New Construction - Rentals

    1. User avater
      james | Dec 29, 2007 05:27am | #10

      You can use as many R/L ( right/left ) assemblys as you want in any area... Around here unions are not allowed period.... but you can still buy them at the hardware store .

       

      james

       

      1. roger g | Dec 29, 2007 06:06am | #11

        Up here in Canada you can use unions, as many as you want I guess but they must be accessible.

        roger

      2. plumbbill | Dec 29, 2007 06:54am | #12

        I noticed you're in SanFran, most of my commercial earthquake flexes have a union on one end or the other.

        "Why do you hurt me when I do bad things to you?" My youngest son to his older brother

        1. User avater
          james | Dec 29, 2007 07:48pm | #18

          I would have to see a pic or your earthquake flexes... the ones we use here look much like a water riser... only cavet here is that we have to leave them accessable.

          I hate R/L fittings but you got to do what you got to do... wish I could use Unions at accessable areas but that's not happening.. Hell we are not even allowed to use plastic/abs for DWV.. all cast or copper. I like hanging Iron but there are many times when I wish I could just use ABS/Plastic... like after hanging for 10hrs.....

           

          james

          1. plumbbill | Dec 29, 2007 08:41pm | #21

            Yes our earthquake flex's must be accessible, they are used to connect to the appliance & look very similar to water heater connectors ( braided stainless).

            So in San Fran is the gas "hard piped" to each appliance, with no flex connectors allowed?

            "Why do you hurt me when I do bad things to you?" My youngest son to his older brother

          2. User avater
            james | Dec 29, 2007 09:00pm | #22

            You can use a 6" flex connector at water heater connections as long as they are indoors and not subjected to mechanical damage... that part is subjective.

            for furnaces etc no flex connector is allowed to pass thru the metal part of the heater but you can use them inside the unit.

            flex connectors are allowed for other appliances like stove etc.

            In the applicatoin you describe we are allowed to use flex, we can also use flex when transitioning to an area that is prone to movement / vibration....like when an item is mounted on a vibraiton dampening block.

            so flex is allowed in a limited ammount of applicaitons but absolutely no three peice compression unions. 

             

            james

          3. User avater
            BillHartmann | Dec 29, 2007 09:48pm | #23

            Are you required to have a whole house earthquake gas shutoff valve?.
            .
            A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.

          4. User avater
            james | Dec 29, 2007 09:59pm | #24

            Depends....

             

            You do not have to put one as a matter of course but if you are making changes to over say 20% of an existing system or are adding on that much you have to install a gas breaker... all fresh installations require one as well.

             

            If I am doing any work near the entrance I put one in... they are really not that expensive and if given the choice 90% of home owners want one installed.

             

            james

      3. TonyCz | Dec 29, 2007 07:44pm | #17

        Here in So Cal, there is what I have learned and called a Gas Union made up on a left right nipple, a left right coupling sold as a set. I have only seen it in a match set up. 3/4" pipe about 7" to 8" long.   Many HD would not know it as a Gas union but may have it wrapped in shrink wrap. Maybe the old school hardware stores may also carry it.  Furgisons should carry it.   

        Edited 12/29/2007 8:33 pm ET by TonyCz

        Edited 12/29/2007 8:34 pm ET by TonyCz

        1. User avater
          james | Dec 29, 2007 07:51pm | #19

          Thats exactly what I am talking about ... Right / Left fitting which is a left/right thread nipple and coupling... see we are on the sme page,

           

          I asked for one at desperado and was told that no such thing....

           

          james

          1. roger g | Dec 30, 2007 03:32am | #25

            Well in almost 4 decades of gas fitting I have never seen or even heard of a left hand thread in gas piping. I'm not saying it isn't out there...............................somewhere. I 've used a left hand thread hooking up old cast iron radiators but that's plumbing.

             

            roger

          2. User avater
            james | Dec 30, 2007 05:22am | #26

            now you have seen one, top hit on google for " right left coupling".

             

            james

             

            Left/Right Nipple And Coupling Set

            View ImageView Image

            These have standard right-hand threads on one side & reverse (left-hand) threads on the other. These are generally used for gas piping, when unions are not allowed.

          3. roger g | Dec 30, 2007 05:58am | #27

            Phew! I'm glad I said "somewhere".

            Thanks. I wouldn't have believed it if you hadn't posted it. I like to learn something every day.

             In the Canadian Gas Code (old) 5.14.3  A pipe fitting containing both left and right hand threads, thread protector or running threads shall not be used.

             

            roger

          4. User avater
            james | Dec 30, 2007 06:22am | #28

            rodger,

             

            We have some pretty funny plumbing rules in the city.. I hate installing those little buggers but I do see why there is a need for them.... My opinion is that they are overused in this jouristiction, many instances a union would be more than sufficient.

             

            james

          5. JulianTracy | Dec 30, 2007 06:35am | #29

            If you must saw it - don't overlook a jigsaw with a good metal cutting blade. Works faster than a handsaw and you can do it with no vibration at all.I used a jigsaw with a fine blade to cut some very tight corners 1/2 copper pipe - and had a clean enough cut to be able to solder on a new fitting.I use my jigsaw with metal cutting blades more than I use it for cutting wood. I haven't used my hacksaw in 5 years.Of course - it's a cordless jigsaw... (bosch 18volt - lots of balls)JT

  6. plumbbill | Dec 29, 2007 06:59am | #13

    I use sawzalls all the time, I prefer my portaband, but I understand not everyone has one ( I have 3) , if you're going to use a sawzall make sure the blade is new, has fine teeth, & make sure the guard stays in contact with the pipe.

    OK I'm probably breaking every safety rule there is with this tidbit, but here it goes--- When cutting something I don't want to vibrate I hold the work with my left hand while my left thumb is on top of the guard applying pressure so the sawzall does not jump back from the work.

    "Why do you hurt me when I do bad things to you?" My youngest son to his older brother

    1. restorationday | Dec 29, 2007 07:32am | #14

      Is that why they call you "Ol' Four Fingers"?

      1. plumbbill | Dec 29, 2007 08:35am | #15

        I have 4 fingers on each hand & two thumbs ;-)

        FWIW I did say on the back of the guard.

        "Why do you hurt me when I do bad things to you?" My youngest son to his older brother

    2. Dave45 | Dec 29, 2007 06:25pm | #16

      Bill -

      I'm a lefty, so I use my right hand to support the work.  If this is a safety issue, 99.9% of the people I've seen using a sawzall are a hazard. - lol

      I suggested that Rich use a hacksaw because a recip saw can be a little tricky to use unless you use one quite a bit.  The hacksaw is slower, but much more gentle on the piping. - lol

      Others have mentioned possible code issues with unions and Rich should look into that.  In any case, the union (and new valve) need to be accessible so that making up and testing the connections is as easy as possible. 

      He may also need to add some support at the union and valve.  Those act as point loads and can create unwanted stresses in the piping if they're unsupported.  (In my engineering days, I did some work on seismic supports of nuclear plant piping and gained a lot of understanding about how it all works.)

      1. plumbbill | Dec 29, 2007 08:38pm | #20

        Unions are allowed in my location, but it must be accessible & there is a limit on how many can be used, but I can't recall the code off the top of my head.

        When I say unions I am referring to the 3 piece ground joint style. A flange can be considered a union & we can put as many of those in as we want & the don't have to be accessible.

        "Why do you hurt me when I do bad things to you?" My youngest son to his older brother

Log in or create an account to post a comment.

Sign up Log in

Become a member and get full access to FineHomebuilding.com

Video Shorts

Categories

  • Business
  • Code Questions
  • Construction Techniques
  • Energy, Heating & Insulation
  • General Discussion
  • Help/Work Wanted
  • Photo Gallery
  • Reader Classified
  • Tools for Home Building

Discussion Forum

Recent Posts and Replies

  • |
  • |
  • |
  • |
  • |
  • |
View More Create Post

Up Next

Video Shorts

Featured Story

Podcast Episode 686: Brick Steps, Ground-Source Heat Pumps, and Greenhouses in Nova Scotia

Listeners write in about fireplaces affecting family harmony and bionic suits, before asking questions about brick steps, ground-source heat pumps, and building a dome greenhouse in Maritime Canada.

Featured Video

How to Install Exterior Window Trim

Learn how to measure, cut, and build window casing made of cellular PVC, solid wood, poly-ash boards, or any common molding material. Plus, get tips for a clean and solid installation.

Related Stories

  • Podcast Episode 686: Brick Steps, Ground-Source Heat Pumps, and Greenhouses in Nova Scotia
  • FHB Podcast Segment: Efficient HVAC for a New Build
  • Affordable Scans, Accurate Plans
  • FHB Summit 2025 — Design, Build, Business

Highlights

Fine Homebuilding All Access
Fine Homebuilding Podcast
Tool Tech
Plus, get an extra 20% off with code GIFT20

"I have learned so much thanks to the searchable articles on the FHB website. I can confidently say that I expect to be a life-long subscriber." - M.K.

Get home building tips, offers, and expert advice in your inbox

Signing you up...

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
See all newsletters
See all newsletters

Fine Homebuilding Magazine

  • Issue 331 - June 2025
    • A More Resilient Roof
    • Tool Test: You Need a Drywall Sander
    • Ducted vs. Ductless Heat Pumps
  • Issue 330 - April/May 2025
    • Deck Details for Durability
    • FAQs on HPWHs
    • 10 Tips for a Long-Lasting Paint Job
  • Issue 329 - Feb/Mar 2025
    • Smart Foundation for a Small Addition
    • A Kominka Comes West
    • Making Small Kitchens Work
  • Issue 328 - Dec/Jan 2024
    • How a Pro Replaces Columns
    • Passive House 3.0
    • Tool Test: Compact Line Lasers
  • Issue 327 - November 2024
    • Repairing Damaged Walls and Ceilings
    • Plumbing Protection
    • Talking Shop

Fine Home Building

Newsletter Sign-up

  • Fine Homebuilding

    Home building tips, offers, and expert advice in your inbox.

  • Green Building Advisor

    Building science and energy efficiency advice, plus special offers, in your inbox.

  • Old House Journal

    Repair, renovation, and restoration tips, plus special offers, in your inbox.

Signing you up...

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
See all newsletters

Follow

  • Fine Homebuilding

    Dig into cutting-edge approaches and decades of proven solutions with total access to our experts and tradespeople.

    Start Free Trial Now
    • Facebook
    • Instagram
    • X
    • LinkedIn
  • GBA Prime

    Get instant access to the latest developments in green building, research, and reports from the field.

    Start Free Trial Now
    • Facebook
    • YouTube
  • Old House Journal

    Learn how to restore, repair, update, and decorate your home.

    Subscribe Now
    • Facebook
    • Instagram
    • X
  • Fine Homebuilding

    Dig into cutting-edge approaches and decades of proven solutions with total access to our experts and tradespeople.

    Start Free Trial Now
    • Facebook
    • Instagram
    • X
    • LinkedIn
  • GBA Prime

    Get instant access to the latest developments in green building, research, and reports from the field.

    Start Free Trial Now
    • Facebook
    • YouTube
  • Old House Journal

    Learn how to restore, repair, update, and decorate your home.

    Subscribe Now
    • Facebook
    • Instagram
    • X

Membership & Magazine

  • Online Archive
  • Start Free Trial
  • Magazine Subscription
  • Magazine Renewal
  • Gift a Subscription
  • Customer Support
  • Privacy Preferences
  • About
  • Contact
  • Advertise
  • Careers
  • Terms of Use
  • Site Map
  • Do not sell or share my information
  • Privacy Policy
  • Accessibility
  • California Privacy Rights

© 2025 Active Interest Media. All rights reserved.

Fine Homebuilding receives a commission for items purchased through links on this site, including Amazon Associates and other affiliate advertising programs.

  • Home Group
  • Antique Trader
  • Arts & Crafts Homes
  • Bank Note Reporter
  • Cabin Life
  • Cuisine at Home
  • Fine Gardening
  • Fine Woodworking
  • Green Building Advisor
  • Garden Gate
  • Horticulture
  • Keep Craft Alive
  • Log Home Living
  • Military Trader/Vehicles
  • Numismatic News
  • Numismaster
  • Old Cars Weekly
  • Old House Journal
  • Period Homes
  • Popular Woodworking
  • Script
  • ShopNotes
  • Sports Collectors Digest
  • Threads
  • Timber Home Living
  • Traditional Building
  • Woodsmith
  • World Coin News
  • Writer's Digest
Active Interest Media logo
X
X
This is a dialog window which overlays the main content of the page. The modal window is a 'site map' of the most critical areas of the site. Pressing the Escape (ESC) button will close the modal and bring you back to where you were on the page.

Main Menu

  • How-To
  • Design
  • Tools & Materials
  • Video
  • Blogs
  • Forum
  • Project Guides
  • Reader Projects
  • Magazine
  • Members
  • FHB House

Podcasts

  • FHB Podcast
  • ProTalk

Webinars

  • Upcoming and On-Demand

Podcasts

  • FHB Podcast
  • ProTalk

Webinars

  • Upcoming and On-Demand

Popular Topics

  • Kitchens
  • Business
  • Bedrooms
  • Roofs
  • Architecture and Design
  • Green Building
  • Decks
  • Framing
  • Safety
  • Remodeling
  • Bathrooms
  • Windows
  • Tilework
  • Ceilings
  • HVAC

Magazine

  • Current Issue
  • Past Issues
  • Magazine Index
  • Subscribe
  • Online Archive
  • Author Guidelines

All Access

  • Member Home
  • Start Free Trial
  • Gift Membership

Online Learning

  • Courses
  • Project Guides
  • Reader Projects
  • Podcast

More

  • FHB Ambassadors
  • FHB House
  • Customer Support

Account

  • Log In
  • Join

Newsletter

Get home building tips, offers, and expert advice in your inbox

Signing you up...

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
See all newsletters
See all newsletters

Follow

  • X
  • YouTube
  • instagram
  • facebook
  • pinterest
  • Tiktok

Join All Access

Become a member and get instant access to thousands of videos, how-tos, tool reviews, and design features.

Start Your Free Trial

Subscribe

FHB Magazine

Start your subscription today and save up to 70%

Subscribe

Enjoy unlimited access to Fine Homebuilding. Join Now

Already a member? Log in

We hope you’ve enjoyed your free articles. To keep reading, become a member today.

Get complete site access to expert advice, how-to videos, Code Check, and more, plus the print magazine.

Start your FREE trial

Already a member? Log in

Privacy Policy Update

We use cookies, pixels, script and other tracking technologies to analyze and improve our service, to improve and personalize content, and for advertising to you. We also share information about your use of our site with third-party social media, advertising and analytics partners. You can view our Privacy Policy here and our Terms of Use here.

Cookies

Analytics

These cookies help us track site metrics to improve our sites and provide a better user experience.

Advertising/Social Media

These cookies are used to serve advertisements aligned with your interests.

Essential

These cookies are required to provide basic functions like page navigation and access to secure areas of the website.

Delete My Data

Delete all cookies and associated data