Continue to Site

Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

  • Congratulations KootK on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Wooden plugs? 1

Status
Not open for further replies.

Pump2005

Civil/Environmental
Jan 14, 2006
72
I am looking to get some wooden plugs to keep on hand for times when a corporation might get pulled out at the main and was wondering if anyone here had any experience with them. What do you use to keep them in place after you hammer them into the stop?
 
Replies continue below

Recommended for you

The wooden plug originated in the 1800's to describe the first efforts to acquire water from underground wooden water mains made of bored-out, crude logs. These logs were tapered at each end to fit together to form a piping system for carrying water. When a fire occurred, firefighters would bore a hole into this log main and collect the outpouring water in buckets or by suction hose. After the fire had been extinguished, wooden pegs- known as fire plugs- were pounded into the drilled holes to stop the flow of water. In some cases, the plug was already inserted into the wooden mains at half-block intervals. When the firefighters needed water, they would simply remove the closest plug.

Have not heard of people using wooden plugs in years.

It seems like it would be just as easy to put a Ford repair clamp on and install a new corporation stop.



 
While I guess there could be by now innumerable variations, I suspect at least the earliest plugs were simply just driven into the holes (with maybe just friction, and who knows maybe also some wood swelling being able to hold them in place vs substantial pressure in the fashion of old taper-bored wood pipe?). Whereas most early plugs were probably just whittled out, I seem to remember seeing such plugs offered to be "store bought" in one of those contemporary waterworks supply places that have everything supply catalogs. If no-one else chimes in, I'll pull that catalog back out when I get back to my office next week.

While on a job several years ago when an old steel transmission line was replaced with ductile iron, the inspector on that job told me of their routine practice of using such plugs on that line. He told me one of their VERY large employees slipped in the process (of yanking one of these things out?) and hit his head, knocking himself out cold as a cucumber down in the water-filled trench. He said they had a sickens of a time getting that huge man up out of the trench in emergency mode!
 
Thanks, bimr (that's the one I remember!)
 
Thanks, I know the history behind them and where I can purchase them but I was wondering if being hammered in would be enough to keep it in place or if a strap of some type is used along with it.
 
Here in Ohio we have kept wooden plugs on hand for emergencies for many years. We keep an old broom handle in each truck and whittle the end down to a taper to drive into corporation holes and pin hole leaks that have eroded into larger leaks. After driving the broom handle into the main we let it soak up water and expand the wood to become very tight, then saw off the handle near the main and leave an inch of plug in the main, then use a clamp over it on an iron main or weld a patch over the plug on a steel main.
 
Thanks Greggy. It would be used as a temporary quick fix where the corporation was pulled out or the copper line was pulled out at the flare and stopping the flow would allow us to clear out the area to give us room to put a repair clamp on or add a new piece of copper and reflare it.
 
I am curious when you mention "corporation pulled out", what kind of main(s) are you dealing with?
 
You do not need to pound in the plug
A light tap is all that is needed, an aggressive impact will drive the plug in so far it will be difficult to remove. The plug is only used until the proper repair can be completed. The plug is used to slow/stop down the flow of water and allow the area to be excavated for the real repair work. The plug will naturally expand to hold itself in.

Corporations are typically pulled out by excavation contractors digging in the streets. The corp will typically shear at the closest thread to the saddle or direct tap. You will need an easy out to remove the remaining threaded section if you plan to replace the corporation with a new corp. Otherwise, a repair band will go over the hole, set the repair band on the pipe next to the wooden plug assemble the clamp so it is ready to tighten, work the plug loose and slide the band over the hole and tighten. This can be done under pressure but not the driest of jobs.

Plugs are available from USABluebook, Pollard Water, or your local Water works distributor.

The standard plugs work well in corps, to plug pinholes you will need to get the small ones or just whittle the standard ones to size. Note on the pinholes, inserting the plug will enlarge the typical pinhole as it is driven in, curling the thin area until there is enough meat in the pipe to hold the plug in place.

Bimr, call me a hick but we used a plug last month just as described above corporation example.

Hydrae
 
Thanks, hydrae for the clarifying/further information. I suspect with your corporations themselves shearing or pulling apart as you describe (leaving a rather smooth, strong hole) as opposed to “pulling out”, you are perhaps dealing with rather strong main material e.g. ductile/iron (or at least corporations threaded into strong iron etc. saddles), not corporations directly threaded into weaker main materials such as pvc etc. That is why I asked the question regarding main materials.

I’m not sure one could plan in the latter case on a wooden plug necessarily as being able to effectively plug up whatever’s left after the service line is snagged (see the direct-tapped service line testing documented at that revealed with regard to the pvc test mains, “In all instances, the pulling force caused the pipe wall to break in the area of the corporation stop, pulling pieces of the pipe wall out in the area of the corporation stops, resulting in destruction of the pipe itself in the general area of the direct tap connection.”)
 
Great information. Our larger mains are ductile iron (4"-16") and usually the corporations are both direct taps and saddles and the corporations are usually 5/8" to 3/4". Luckily we don't have PVC lines for water only sewer where there have been repairs.
 
Status
Not open for further replies.

Similar threads

Part and Inventory Search

Sponsor