Re: PVC pipe as dryer vent

[kempshomeandlawncare]

melting point of pvc is higher than that if it melted ay 120 you gould not use it for you hot water in your house

[Frank]

PVC is only good to 140 deg F. You are talking about CPVC or chlorinated PVC which is used in hot water pipes. CPVC is good up to

200 deg F. These are not melting points but glass transition points where the polymer softens and becomes flexible but does not melt.

I had what was probably a PVC coated flexible drier vent and was told by a repairman that it did not meet code. I replaced it with flexible metal tubing.

[RosemontCrest]

1) The post to which you replied is more than four years old. 2) 140 degrees C is 284 degrees F. Is your water heater set to 140 degrees C?

[micky]

C = Centigrade, or Celsius as the hippies like to call it.

140/5 = 28, x 9 = 252, + 32 = 284 Fahrenheit.

120 F.

[gfretwell]

You can't. You have to use CPVC, a different plastic compound. I have never seen

4" CPVC but I suppose someone might make it. You just don't find it at the Home Depot.

[gfretwell]

Regular white PVC will get soft enough to bend in boiling water. I have done it many times.

[RosemontCrest]

Yes, I was referring to the previous claim of 140 and 160 degrees C.

[Clare Snyder]

People used to use flexible plastic "duct" for dryers - the stuff with the wire coil in it. I've seen it wherer basically only the coil was left intact - with the plastic melted right out. That crap hasn't been legal for likely 30 years or more (if it ever was) and I'm sure it has caused more than one dryer fire. Bending PVC works from 170 degrees up to about 220. Any hotter it gets way too soft and looses shape.(all temperatures in "Yankee" degrees)

[gfretwell]

I have done it with conduit more than plumbing pipe but other than color and U/V additives, it is the same stuff. One tip, slip a cold connector over the end as soon as you remove it from the heat if you did immerse the end in the hot water (or in the tail pipe of the truck). Then it will retain the shape and size while you are making the bend. Douse it with water to hold what you have.

[micky]

My house came with that. Counting the 4 years before I got here, it lasted about 30 years until a rip appeared just above the dryer. I leaned a towel against the rip to keep te air in and it lasted another 5 years. After that, I had to replace it.

[kelown]

Isn't PVC wire hosing still used for portable air conditioner exhaust?

(hose with wire reinforcement)

[Clare Snyder]

Portable AC exhaust isn't hot.

[kelown]

Obviously. But my question was referring to the material the hose is made of, to help determine whether such hose material is still being legally sold.

[Frank]

CPVC I heard is brittle. Guy here had replaced his copper plumbing with it and told me he was working near some of it under the sink and grabbed it to position himself and it broke.

Most PVC we see is plasticized to make less brittle.

Regardless of the softness or melting point there is a fire hazard using it in a drier vent as a fire in the vent would break out. Most plastics could not handle a fire in the vent.

The stuff I had, a PVC coated spring got full of lint because birds were getting in the vent and nesting. If the cat had not jumped to the top of the drier hearing the birds we might not have known it and a fire could have started. I had cleaned the tubing and the vent but it was afterwards that an appliance repairman told me my old piping was out of code. If we had a fire we could have a problem with insurance covering it.

Might mention I put a cage over the old vent flaps to keep out birds.

Many years ago we rented a house with drier in the basement and vent was at ground level. A rabbit crawled into the vent and got dried to death. Took a couple of days to get a repairman. We did not know about the rabbit but just knew the drier was not working. Weather was warm and by the time the repairman got there the rabbit was full of maggots. Hell of a mess and odor in drier would not leave.

[Clare Snyder]

What's that got to do with the price of brown eggs in idaho on even-numbered Tuesdays??? The thread was about DRYER VENTS

[gfretwell]

This is the land of plastic plumbing and we also use PVC for lots of other things. Sunlight will make it more brittle after a while but it is still not glass. I have gopher tortoise burrow markers made from

3/4" PVC that have been out in Florida the sun for over a decade and they still bend. CPVC doesn't seem to be affected any more than PVC but if you are worried about it, use RNC (gray conduit). It is UV stabilized.

[Frank]

I know that PVC holds up well in sunlight. Went through this issue a couple of years ago discussing a Trex deck. Trex is coated with PVC because the original PE is not sunlight resistant.

I've been told by plumbers over the years that copper does not hold up with our well water and neighbors have replaced it with CPVC and PEX. So the CPVC comment is only from one neighbor. The PEX neighbor had numerous leaks at the fittings.

I was 20 years ago with a pinhole leak in the copper that the plumber recommended replacement but I have not had another leak since.

I have also since replaced the plumber.

On the original subject, we were addressing building codes. They do change over the years and have additions to them.

[Rod Speed]

There was a problem with pinholes in copper made in the early 70s I've seen it in two houses built at that time

[Frank]

I suspected something like that. Probably more of mechanical defects in pipes rather than the copper itself. Only leaks I have had since were in two shut off valves, also probably defective.