Roof Top Unit drip leg location?

[SCBO1]

Where should a Roof Top Unit (RTU) drip leg be located when gas supply feed is at the roof?

IFGC 408.3, A drip leg shall not be located where the condensate is subject to freezing. Gas lines are ran above the roof to the units with valve, union and drip near the RTU, how does the installer meet this code if subject to freezing?

pc1

 

[north star]

* * * *

Possibly, thermally insulate the entire gas line. :surr There

will be [ some ] moisture in the entire length of line, ...yes?

& & & &

 

[Francis Vineyard]

Does you area have wet gas?

408.2 Drips. Where wet gas exists, a drip shall be provided at

any point in the line of pipe where condensate could collect. A

drip shall also be provided at the outlet of the meter and shall be

installed so as to constitute a trap wherein an accumulation of

condensate will shut off the flow of gas before the condensate

will run back into the meter.

408.3 Location of drips. Drips shall be provided with ready

access to permit cleaning or emptying. A drip shall not be

located where the condensate is subject to freezing.

408.4 Sediment trap. Where a sediment trap is not incorporated

as part of the appliance, a sediment trap shall be installed

downstream of the appliance shutoff valve as close to the inlet

of the appliance as practical. The sediment trap shall be either a

tee fitting having a capped nipple of any length installed vertically

in the bottommost opening of the tee or other device

approved as an effective sediment trap. Illuminating appliances,

ranges, clothes dryers and outdoor grills need not be so

equipped.

 

[mtlogcabin]

Francis nailed it. Call your gas utilities and have them provide a letter stating if they supply a wet gas or dry gas to their consumers.

 

[globe trekker]

Is Section 408.2 requiring only one drip, or two? In this case, one at the RTU

A N D one at the meter itself, or is only one required in the whole gas line

run?

.

 

[SCBO1]

I've called the gas supplier, he claims they have dry gas and that most likely I'm looking at a sediment trap which I would have to agree. But, I have taken a many black iron caps off a gas line to start a new furnace for the sheetrockers before and most had rusty water drip out on the floor. could be condensation in the gas line being new lines?

pc1

 

[Builder Bob]

The condesate that you are finding is because the piping has not been purged and placed in use.... this is residual condesation(water) if from the pipe when it is installed and allowed to breathe to the general atmosphere.....