# sediment trap with gas flex line?



## diggerdave (Feb 10, 2009)

I'm installing a new water heater with a natural gas flex line. Initially I was going to connect the flex line and adapter directly to the water heater (as stated in the flex line instructions). 

However I'm seeing other installations using flex tube connected to a vertical sediment trap, tee, and horizontal black pipe to the heater. Similar to my current setup in the picture, except from the union up is the flex tubing. Also my neighbor mentioned his furnace didn't run right without a trap. 

Should install a sediment trap again? Is that always recomended? If so, can I reuse what I have after cleaning the threads, or is new piping always recomended?


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## bigMikeB (May 31, 2007)

You always need to have a drip trap in a gas line to avoid sediment and moisture from getting into the gas valve itself. If you are using a flex, (which I don't know why you don't just tie in solid as the old heater was done) then turn the outlet of the tee away from the heater and pipe in your flex from that point to the new gas valve.


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## diggerdave (Feb 10, 2009)

Thanks bigMikeB. Wouldn't there be a problem with disconnecting that nipple from the heater to the tee? Loosening the nipple from the heater tightens the nipple to the tee. I don't think there would be enough play in that conncetion to get er done. If I disconnceted the union it doesn't appear I would have clearance to turn the trap and tee off the nipple. Looks like I would have to disassemble piece by piece back to the heater, then reassemble for the new heater.

Also I'm upgrading from a 40 to 50 gallon heater and the width/depth is an additional 2". The problem is I'm not sure I'll have enough room to squeeze the new heater in place, considering the pipe angle of the old 60" gas supply from the ceiling (see pictures). If I straightend the pipe out vertical I would most likely have to shift the heater to the right, add a 45 degree angle to the vent pipe and maybe have to adjust the water supplies.

Since I have to install a gas shut-off valve, I thougt I would gain some flexibility if I replaced the 60" supply line from the ceiling with a 18-24" pipe, shut-off valve, flex pipe to the trap. Once I get the new heater in place, I'll have a better idea what my clearances are.

What do you think?


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## Termite (Apr 13, 2008)

Never hurts to install a drip leg. Some inspectors require it, some don't. You can use black pipe for the drip leg and install it on the water heater. If you want to use flex...Which is just fine...Run flex between the shutoff and the drip leg. If you use flex then you don't need a union.


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## diggerdave (Feb 10, 2009)

thanks thekctermite. Is a drip leg the right term, but the same thing as a sediment trap? Like in my old setup in the picture. Sounds like it, but I don't want to assume. Thanks


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## 47_47 (Sep 11, 2007)

Because you currently have no shut off, I'd shut it off where I could, disconnect the union and remove the 60" pipe from the tee. Insert a short length of pipe and a shut off. Then you can turn the rest of the house back on. I'd repipe (solid), but I thread my own. You can do a lot with a couple of 45° elbows to keep the larger new tank in the same spot. Test your connections.

Good luck


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## Michael Thomas (Jan 27, 2008)

"Sediment trap" is the correct term for the code required trap:
_
G2419.4 *Sediment trap*. Where a sediment trap is not incorporated as part of the gas utilization equipment, a sediment trap shall be installed downstream of the equipment shutoff valve as close to the inlet of the equipment as practical. The sediment trap shall be either a tee fitting with a capped nipple in the bottom opening of the run of the tee or other device approved as an effective sediment trap. Illuminating appliances, ranges, clothes dryers, decorative appliances and outdoor grills need not be so equipped unless specifically required by the appliance manufacturer's installation instructions._


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## bwalley (Feb 10, 2009)

diggerdave said:


> I'm installing a new water heater with a natural gas flex line. Initially I was going to connect the flex line and adapter directly to the water heater (as stated in the flex line instructions).
> 
> However I'm seeing other installations using flex tube connected to a vertical sediment trap, tee, and horizontal black pipe to the heater. Similar to my current setup in the picture, except from the union up is the flex tubing. Also my neighbor mentioned his furnace didn't run right without a trap.
> 
> Should install a sediment trap again? Is that always recomended? If so, can I reuse what I have after cleaning the threads, or is new piping always recomended?


I wouldn't use a flex connector, stick with the black iron you have, but add a shut off, you are supposed to have a gas shut off valve within 6' of the appliance in the same room.


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## Michael Thomas (Jan 27, 2008)

bwalley said:


> I wouldn't use a flex connector, stick with the black iron...


Digerdave does not have a location listed, but if he's in a seismically active area a flexible connector may be recommend or required, see for example: www.seismic.ca.gov/HOG/waterheaterbracing_08-11-04.pdf


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## bwalley (Feb 10, 2009)

Michael Thomas said:


> Digerdave does not have a location listed, but if he's in a seismically active area a flexible connector may be recommend or required, see for example: www.seismic.ca.gov/HOG/waterheaterbracing_08-11-04.pdf


Based on his pictures, he is not in an area where seismic activity is a concern.


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## diggerdave (Feb 10, 2009)

Correct, I live in S. Wisconsin and don't have to worry about that. I plan on going solid pipe, installing a shut-off and keeping the sediment trap. 

I think I need to disassemble from the union to the heater and reassmeble from the new unit because of the threads. Loosening the nipple at the heater input, would tighten the nipple to the tee, and I don't have clearance to turn the whole setup off (picture above). ???

I would like to install the shut-off high so children don't mess with it. I was thinking of installing a 12" or 18" pipe off the ceiling tee, then the shutoff. That would be about six feet from the floor. 

One problem though is figuring out how to get rid of the angle. Using a plumb bob, it's roughly 3-4" off over the length of the current 60", just below the union. If I try to turn the tee in the ceiling, I may break the thread seal, and that run continues on. So I'd like to leave it alone if possible. If I use 90's or 45's the angle would still remain. ???

It's hard to tell what clearance I'm going to have at the top of the new heater. I'm going from a 40-50 gallon. There's a 1/4" gap between the pipe and current heater, and a 2" clearance from back of the heater to the chimny. The new heater is roughly 2" wider and 1-1/2" higher. It might just work.

I'm just trying to get pipe preped for what will happen once the new heater is in place and minimize downtime for the furnace. Any thoughts or ideas are welcome and appreciated.


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