# Why Drip Legs?



## kimo (Jul 22, 2011)

I made the title a bit cheeky to attract attention and separate it from the "Home Depot W/H ..." post below.

In my short time in the trade i've yet to be required to install a drip leg on a new W/H, or have one required by any PI. And we had some very demanding PI's, especially in Berkeley Ca. who would pull us up for the slightest Code violation.

A plumber, who's been working mostly tracts from 1979, told me that he rarely installs them at W/H's either.

Out of curiosity, I've examined drip legs from a number of old redundant natural gas W/H's, and many of them have been free from "dust" or particles. Yet, at the same locations, horizontal lengths of old black pipe were often contaminated with particles of "dust".


I say "dust" because i dont know what it was.


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## smartbrad (Apr 22, 2013)

If dope or tape is being pushed through the pipe it should fall into the dirt pocket before entering the gas valve. It would screw up the gas pressure at the valve and probably make the burner fire improperly.


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## Burner tech (Oct 24, 2013)

When installed correctly, the drip leg will catch plenty of debris. I have opened some that are just packed full.


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## plbgbiz (Aug 27, 2010)

Cutting oil, dirt, moisture. They can all accumulate in the drip leg. A lot depends on the layout of the system.


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## Burner tech (Oct 24, 2013)

I have opened plenty that are empty and plenty that are packed full. I would rather see the drip leg full of debris than see it in the gas valve.


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## Plumbworker (Oct 23, 2008)

kimo said:


> I made the title a bit cheeky to attract attention and separate it from the "Home Depot W/H ..." post below.
> 
> In my short time in the trade i've yet to be required to install a drip leg on a new W/H, or have one required by any PI. And we had some very demanding PI's, especially in Berkeley Ca. who would pull us up for the slightest Code violation.
> 
> ...


I didnt know the city of berkeley had any plumbing inspectors on staff.. I helped my friend 4 years ago with some plumbing renovations and all they had was a couple of combination inspectors running around..:laughing:


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## dhal22 (Jul 30, 2010)

It's a simple item, no need to NOT do it. As said before, cutting oil, rust, etc, etc. Why not? All 29 years of me installing heaters have seen me use drip legs.

David


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## plumbdrum (Nov 30, 2013)

kimo said:


> I made the title a bit cheeky to attract attention and separate it from the "Home Depot W/H ..." post below. In my short time in the trade i've yet to be required to install a drip leg on a new W/H, or have one required by any PI. And we had some very demanding PI's, especially in Berkeley Ca. who would pull us up for the slightest Code violation. A plumber, who's been working mostly tracts from 1979, told me that he rarely installs them at W/H's either. Out of curiosity, I've examined drip legs from a number of old redundant natural gas W/H's, and many of them have been free from "dust" or particles. Yet, at the same locations, horizontal lengths of old black pipe were often contaminated with particles of "dust". I say "dust" because i dont know what it was.


If you use NFPA 54 it's a code requirement, also it protects your gas valve from getting possible debris in it, also just good mechanical practice.

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## love2surf927 (Dec 22, 2011)

Plumbworker said:


> I didnt know the city of berkeley had any plumbing inspectors on staff.. I helped my friend 4 years ago with some plumbing renovations and all they had was a couple of combination inspectors running around..:laughing:


Sounds par for the course here in California.


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## wyrickmech (Mar 16, 2013)

Most of the time it will void warranty if you do not install one. Just because you have PI,s that don't know the proper install does not mean that it isn't wrong.


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## Plumbworker (Oct 23, 2008)

I've seen plenty of trash sitting in drip legs they do have a purpose..drip legs also give the ability for a pressure tap to hook a manometer to..

You think berkeley inspectors are tough i gotta deal with 18 or so dedicated plumbing inspectors in my city that interpert the plumbing code differently from one another..


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## kimo (Jul 22, 2011)

Plumbworker,

Yeah, every plumber that's worked in the city (San Francisco) has a grim tale to tell about the PI's over there. One plumber who lived in SF decided to travel to, and work in, Walnut Creek rather than deal with the SF PI's.

I've only worked South San Francisco, and at a famous person's house in Hillsborough where the boss got in trouble for not having a business license.
He exploded "a guy can't walk out the door without getting a Godamn license of some kind". He never takes jobs in SF.


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## JK949 (Mar 18, 2009)

It is in UPC, inspectors around here are catching wind of it. When I first started 7 years ago, no one I worked with put them on. Then the Icon gas valve came out. Every heater I install gets one, tank or tankless.


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## Team BP (Feb 12, 2011)

Once again here in the Mass code it's just part of the standard installation. I don't think I've ever seen a appliance without a drip leg. Sometimes we put them in at the bottom of a riser and if it's weld pipe absolutely all the slag has to go somewhere after time.


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## plumbdrum (Nov 30, 2013)

Team BP said:


> Once again here in the Mass code it's just part of the standard installation. I don't think I've ever seen a appliance without a drip leg. Sometimes we put them in at the bottom of a riser and if it's weld pipe absolutely all the slag has to go somewhere after time.


Not required on all appliances , but most, also just good mechanical practice to do it.

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## Steveking (May 16, 2014)

Failed inspection in the city of imperial beach ca. Because no drip leg on a wall heater? Drip leg was a close nipple with cap at gas value going to catch lots of debris now talked to inspector in near city said drip legs are for " wet gas" does not enforce drip legs on appliance but only on water heaters.


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## dclarke (Dec 22, 2012)

I put drip legs on every heater and water heater. I've thought about putting them on the main at an elbow instead of a 90 to catch the majority if debris. Never have though.


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## Master Mark (Aug 14, 2009)

someone on this site stated the on the newer Icon and honeywell gas valves you are running into , they are more
sensitive to dirt and it is best to have one on them....

I have seen it both ways many, many times....


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## plumbdrum (Nov 30, 2013)

In our old gas code, you would have to take a branch/ drop off the vertical to prevent debris from dropping and also install drip leg/ sediment trap due to possible moisture . Now we just enforce drip/ sediment only

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## bobtheplummer (Sep 29, 2012)

In maryland drip legs were required when gas was actually imported in a cold state that produced a lot of condensate. This was terminated in the 70's and since drip legs were reduced to a "plug" Gas meters in Maryland are used to trap condensate as well.Of course types of gas being used difer also. I am referring to Natural Gas.


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## Associated Plum (Nov 4, 2008)

Natural gas had different types of contaminates such as sulphur, moisture, etc... and drip legs were used to catch these, but with cleaner gas we don't use them like we used to.


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