PDA

View Full Version : Gas Drip Leg



Tony Mount
03-17-2011, 07:38 PM
Is there a installation to a water heater or heater that does not need a drip leg installed on the gas line before it is connected to the appliance?

Jerry Peck
03-17-2011, 07:46 PM
Drip leg or sediment trap? You said drip leg, but I want to make sure you did not mean sediment trap.

Sediment trap:
- Yes ... and ... no.
- Yes, one sediment trap could be used for two appliances is the gas piping was done correctly.
- No, even if one sediment trap were to serve two appliances, each appliance would still have a sediment trap (albeit the same sediment trap), therefore ... no.

Drip leg:
- Yes.
- A drip leg is for the gas piping system with "wet" gas being used, and the drip leg would be at the lowest point of the system. That lowest point would likely not be the appliance (although it could be if the appliance was in a basement, in which case you could see a drip leg at the appliance).

Robert Darsie
03-21-2011, 05:08 AM
I do believe as code, all appliances shall have a drip leg before the appliance

John Kogel
03-21-2011, 06:36 AM
Welcome Robert. Just so you know, we call them sediment traps here, even though the people who write the manuals for the products call them drip legs. :cool:

Jerry Peck
03-21-2011, 05:42 PM
I do believe as code, all appliances shall have a drip leg before the appliance


Welcome Robert. Just so you know, we call them sediment traps here, even though the people who write the manuals for the products call them drip legs. :cool:


"we call them sediment traps here"

The code calls them sediment traps, which is why "we call them sediment traps here". :)

The code does have a drip leg also, but for an entirely different reason and use, and seldom (if ever) would one be located at the appliance (see my explanation in my post above).

Harry Janssen
03-21-2011, 05:49 PM
Call them what you want,they serve the same purpose

H.G. Watson, Sr.
03-21-2011, 09:51 PM
There is more than one model "code" and more than one "model code" writing body. There are then the applicable "codes", that which is locally adopted to law. There are also instructions and indications from the appliance manufacturer, and the supplier of gas control valves, used by the apploiance manufacturer, etc. and more critical applications, such as high altitude, low oxygen, low density, combustion air availability, etc. As well as the requirements and/or recommendations of the gas supplier/utility regarding the quality and delivery of the gas supply, i.e. entrained air, condensation, etc.

Tony, it depends. If there has been no elevation and/or subsequent drop to the line, (gas supply system) within a conditioned space, a subsequent "drip leg" may not be either necessary nor required. Some gas valve manufacturers and equipment manufacturers may "suggest" or "recommend" a sediment trap and/or a drip leg prior to the gas valve of the appliance even where the cited standard or code reference does not.

Generally this is more common on automatic fired equipment and that which "recommended" service inspection/maintenance intervals is recommended by qualified technicians.Those appliances which involve human intervention to operate "on demand" such as a cooktop, range, clothes dryer, etc. generally don't expressly "require", but circumstances and conditions of the overall installation may depending on all the considerations, including a drop in the line, from where, to what, and how it is executed; and special considerations regarding higher altitudes, swings in temperature, the gas supply system (utility and local structure).

Although you didn't specify pipeline/utility delivery of natural gas, I presume that is what most if not all are assuming. I'm kicking around different gas valves, listing/standard requirements, automatic vs. on demand, vented regulator applications, and bottled gas supplies NG and propane and what other meanings of "heaters" there are esp. outside the usual residential appliance gas valve applications in the great mid-west and thinking, in general and to your OP, and installation scenarios, and come up with "it depends".

Jerry Peck
03-22-2011, 06:32 PM
Call them what you want,they serve the same purpose


Harry,

Have you not been reading the above posts?

Sediment traps and drip legs serve COMPLETELY DIFFERENT purposes.

John Kogel
03-22-2011, 10:26 PM
Harry,

Have you not been reading the above posts?

Sediment traps and drip legs serve COMPLETELY DIFFERENT purposes.Maybe he meant the Dirt Leg? :)

Garry Sorrells
03-23-2011, 08:59 AM
Maybe he meant the Dirt Leg? :)

If a Drip Leg , Dirt Leg and a Sediment Trap are located in the same place then what do you call it???

Bob Harper
03-23-2011, 02:06 PM
Look, I realise a lot of you think it is picking fly poop out of black pepper to insist on using correct terminology but.........

You are being hired for a professional report. Pros try to use correct terminology whenever appropriate. Have you ever read the report from a professional boat survey? I does not read anything like: "the front right of the boat has a really bad spot in the shell of the boat that appears to be from the fiberglass going bad".... instead of something more like, "There is a section on the starboard aspect of the bow just above the loadwater line that appears to be delamination of the glass resin polyester from osmosis. Further testing revealed...." Home inspectors should get into good habits instead of proliferating bad ones. Now, could you imagine a medical report written in layman's terms? This is why there is standardization of medical terminology including terms for direction and orientation of the patient. For the record, in medical terms, the 'right' side is the patient's right--not as viewed by you. You can adopt this terminology for your home inspection reports, too: anterior is front/ posterior is rear, superior is up/ inferior is down; proximate is close to the body while distal is moving away from the body and so on.

Gary, you can state there is a trap in the fuel gas piping within 6 feet of the appliance that appears to functioning to collect sediment by gravity or you could call it a sediment trap. Calling it anything else is unprofessional and incorrect. Should be you involved in litigation, little errors like this can be used against you to demonstrate your lack of knowledge or carelessness. I take pride in correcting HVAC technicians, plumbers and above all, code officials all the time. BTW, yes, I do find foreign material in these traps often when I open them.

Just curious---for your naysayers on the proper use of terminology: how many of you refer to your report as a "certification, evaluation, assessment, examination, etc." instead of an "inspection"? You know, the meaning of words aren't really all that important are they?
Have a good day,

Jerry Peck
03-23-2011, 06:35 PM
If a Drip Leg , Dirt Leg and a Sediment Trap are located in the same place then what do you call it???

"Dirt Leg and a Sediment Trap"

Those one both "sediment traps".

A "drip leg" serves an entirely different purpose.

Bob H. put forth very clearly what we should use the correct terminology, or are you saying that your report are "certifying the work you looked at" (thank you, Bob, you put that forth in a straightforward way, if any miss it, well, I guess there is no hope for them anyway).

Wayne Carlisle
03-24-2011, 08:23 AM
We require sediment traps but we don't require a drip leg.

So they are not the same!

the gas here is not "wet" enough to require a drip leg.

Mike Gault
03-24-2011, 04:19 PM
Hmmm,

A picture from inspection today.

Should I call it an improperly oriented 'sediment trap' or an okay 'drip leg'?


P.S. We don't 'do' drip legs here... :-)

Garry Sorrells
03-25-2011, 07:37 AM
Jerry,
Know that by definition of purpose that sediment trap/dirt leg are same and by definition of purpose a drip leg is different.

Point was by design and location a sediment trap becomes a drip leg if you have wet gas or does a drip leg with no wet gas become a sediment trap.

Looking at applications of these two items it becomes blurred if you do not know it the gas is wet or not.

By my understanding a public supply natural gas is most often dry as opposed to LP gas which is usually considered wet. If wrong please correct me.