Cutting NPT threads on PVC pipe
Richard J Kinch
connect it in the space available, I need what in steel pipe you would call
a threaded nipple, except in 2-inch PVC pipe. That is, instead of gluing a
PVC male adapter, which would add too much length. Swimming pool plumbing
has to be all plastic due to the chemistry of the water.
Now Home Depot threads steel pipe, with a nice powered pipe threader on the
plumbing pipe aisle, but when I asked them to thread some PVC they
practically called me a pervert. They said the only way to get threads on
a PVC pipe was to glue on a male adapter, and you can't thread PVC pipe.
However quite a few bits of the PVC pool plumbing appear to have been
threaded on-site. And interestingly, the classic Ridgid 12R pipe threader
has replacement dies specifically for PVC:
http://ridgid.com/Tools/Hand-Threader-Die-Heads/
So is threading PVC pipe an unnatural abomination like the top industry
experts at Home Depot, in their orange aprons, assert? Or just not often
worth the labor versus a glued fitting?
Gunner Asch
wrote:
They didnt have already threaded 2" joints/fittings of variou types?
They are common as dirt here in California HDs
Gunner
The current Democratic party has lost its ideological basis for
existence.
- It is NOT fiscally responsible.
- It is NOT ethically honorable.
- It has started wars based on lies.
- It does not support the well-being of americans - only billionaires.
- It has suppresed constitutional guaranteed liberties.
- It has foisted a liar as president upon America.
- It has violated US national sovereignty in trade treaties.
- It has refused to enforce the national borders.
...It no longer has valid reasons to exist.
Lorad474
Karl Townsend
> So is threading PVC pipe an unnatural abomination like the top industry
> experts at Home Depot, in their orange aprons, assert? Or just not often
> worth the labor versus a glued fitting?
I see McMaster has them in several lengths.
http://www.mcmaster.com/#pvc-pipe-nipples/=5hexxy
Or fire up your lathe and make yer own. Use honed HSS and like 20 degree
rake
Karl
Jim Wilkins
> On Fri, 22 Jan 2010 02:45:13 -0600, Richard J Kinch <ki...@truetex.com>
> >So is threading PVC pipe an unnatural abomination like the top industry
> >experts at Home Depot, in their orange aprons, assert? Or just not often
> >worth the labor versus a glued fitting?
>
> They didnt have already threaded 2" joints/fittings of variou types?
> They are common as dirt here in California HDs
>
> Gunner
The threaded ones I've found at HD and Lowes were grey, and not in the
same area as white DWV fittings.
When I thread plastic pipe for mechanical projects I use electrical
conduit. It cuts very well with HSS.
jsw
Lloyd E. Sponenburgh
news:Xns9D08262CA89...@216.196.97.131:
> So is threading PVC pipe an unnatural abomination like the top
> industry experts at Home Depot, in their orange aprons, assert? Or
> just not often worth the labor versus a glued fitting?
>
Richard, it is "an obama-nation" because it condemns the pressure rating
of the pipe. In your instance, the fittings aren't probably under more
than 15-20psi, so it might be acceptable.
However, unless there's an ell just downwind of the pump, why not whack
off the pipe shorter than necesary, and apply a "repair union" to join
the main line to the nipple section.
Repair unions use rubber compression grommets to seal around the pipe,
and permit the user to slide one or the other end back and forth to
shorten or lengthen the section as necessary for fit-ups.
This would not only solve your existing problem, but mitigate the
difficulties of changing the pump in the future.
LLoyd
Pete C.
Schedule 80 PVC is commonly available threaded. Depot and the like carry
it in smaller sizes, probably need to go to a "real" plumbing supply
place for larger sizes.
Ned Simmons
All the threaded PVC I've seen in process piping was schedule 80. I've
never witnessed PVC being threaded on site, but I'm not aware of any
reason it can't be as long as the pipe wall is heavy enough. I wonder
if the thread form is modified to account for the PVC's physical
properties? Threaded PVC joints are more prone to leaks than
metal-metal joints and must be made up carefully to avoid leaks.
Fittings with metal inserts are available to minimize the problem.
--
Ned Simmons
Randy
<ki...@truetex.com> wrote:
Like others have said....
You can thread sch80 but not sch40. It can be done with a standard
pipe threader, but I would suggest NEW dies. Ones used on steel will
most likely chew up the PCV. The dies Ridgid sells for PVC have a
differant rake angle on them to cut nicer than the ones for steel.
Mcmaster Carr is most likely your best bet if they have the lenght you
need. MCM-C is where I go for PVC or Stainless, the plumbing houses
around here just look at you strange if you ask for SS or threaded
PVC.
Heck, I had to McM-C galvanized steel fittings for my air lines as the
local plumbing house no longer carries that stuff either. Houses are
all plastic now. Soon it will be tough to find copper.
Thank You,
Randy
Remove 333 from email address to reply.
Paul Hovnanian P.E.
How long a nipple do you need? I've seen short ones at plumbing supply
places. Your best bet might be to look somewhere other than Home Depot.
The usual thinking is that if you've got enough room, its easier to glue up
two make threaded-female glue adapters with a short piece of 2" PVC.
There's probably a range where there's not enough room for such an
assembly, but a nipple will be hard to find.
--
Paul Hovnanian pa...@hovnanian.com
----------------------------------------------------------------------
Have gnu, will travel.
Gunner Asch
Rigid actually sells dies for threading PVC. I was made aware of this at
the factory (now shut down and for sale) where I keep my Stuff, in So.
Cal. They threaded miles of PVC and was made aware of the differences.
Odd looking dies when compared to steel pipe dies.
Ecnerwal
Richard J Kinch <ki...@truetex.com> wrote:
> My swimming pool pump quit, and the new one is just slightly longer, so to
> connect it in the space available, I need what in steel pipe you would call
> a threaded nipple, except in 2-inch PVC pipe. That is, instead of gluing a
> PVC male adapter, which would add too much length.
It's PVC plumbing. Rather than think about it like it's steel pipe and
make it complicated, think about it like it's PVC pipe, and it gets
simple, messy, but simple.
If it's too long, you cut it off, chop out the amount needed to shorten
it, and glue in a coupling. If you need to "stretch" it (which seems to
be your original need before the too-long fitting), you chop it off, cut
a section of pipe long enough to stretch it as much as you need, and
glue in two couplings - allowing for the center length of the coupling
in both cases. If you don't have enough room to put the coupling bodies
there, you chop it before the next fitting where there will be room for
a coupling and replace with pipe the right length and new fittings. If
you only need to add a little bit, you may need to cut some out so the
added in piece will be long enough for two couplings, or you buy a new
end fitting and only use one coupling.
Sch 40 is not normally threaded - your pool installers may have done so,
since pool plumbing is often operated at low pressure and threading
costs less than adapters, especially when you are plumbing up lots of
pools and getting out of town before they break... The HDs and Lowes of
the world (at least the ones I've been in) generally don't have any
Sch80 on site and may not be able to get any. Even Sch80 is more prone
to fail when threaded than when glued.
--
Cats, coffee, chocolate...vices to live by
Jim Wilkins
<MyNameForw...@ReplaceWithMyVices.Com.invalid> wrote:
> In article <Xns9D08262CA891Csomeconund...@216.196.97.131>,
> Richard J Kinch <ki...@truetex.com> wrote:
>
> > My swimming pool pump quit, and the new one is just slightly longer, so to
> > connect it in the space available, I need what in steel pipe you would call
> > a threaded nipple, except in 2-inch PVC pipe. That is, instead of gluing a
> > PVC male adapter, which would add too much length.
>
> It's PVC plumbing. Rather than think about it like it's steel pipe and
> make it complicated, think about it like it's PVC pipe, and it gets
> simple, messy, but simple.
Pool plumbing has too many expensive custom fittings to think about it
as just ordinary PVC plumbing.
jsw
Bob La Londe
"Richard J Kinch" <ki...@truetex.com> wrote in message
news:Xns9D08262CA89...@216.196.97.131...
Might have to go on-line, but I have purchased threaded PVC nipples before.
The ones I got were in smaller sizes. Don't know if larger sizes are
available or not.
Remember at Home Depot they always treat you like an idiot if "they" don't
know what you are talking about. After all Home Depot goes out and hires
the very best of those who couldn't hack it as a tradesman or a contractor.
When I run into the rare Home Depot employee who admits they might not know
something and asks me for more information I offer them a job if I'm hiring.
Richard J Kinch
> However, unless there's an ell just downwind of the pump, why not whack
> off the pipe shorter than necesary, and apply a "repair union" to join
> the main line to the nipple section.
Because I had only 4 inches of room to put a 3.5" long union between a tee
shoulder and the female coupling on the pump strainer basket. The old
system had no union on the suction side of the pump, so you had to
disassemble the pump (ugh!) to unscrew the threaded fitting.
Two pumps and a filter are all housed in an underground vault (I know, I
know, this was madness, but not of my origination). You can see an old
photo here, with the strainer basket near the bottom of the photo:
http://www.truetex.com/protect/poolctrl3.jpg
I'm actually thinking I should have checked Lowe's since they have a
selection of Sch 80 PVC bits. But too late, I bought a 2" threader and
made my own PVC nipple. It seemed to work out fine.
Richard J Kinch
> They didnt have already threaded 2" joints/fittings of variou types?
They have female slip (glue) adapters to thread, but not (ale) threaded
pipe nipples. An adapter is too long, I must have a nipple to fit the
space available.
Jim Wilkins
> .... I offer them a job if I'm hiring
What do you do?
jsw
Pete Keillor
In the chemical plants I worked in, Sch. 80 was required for all
nipples below 3/4" in all metal fittings as well. There were too many
instances of d/p cells, etc. breaking off in some nasty service or
another.
Pete Keillor
Bob La Londe
news:ce158884-4e57-433e...@v25g2000yqk.googlegroups.com...
I'm a communications contractor. Video, phone, data, access, alarm, sound,
etc. A lot of related experience including aerial and underground
applications. Licensed since 1994. Almost all learned on the job or self
study. Education is in CIS and business.
Gunner Asch
wrote:
>"Jim Wilkins" <kb1...@gmail.com> wrote in message
>news:ce158884-4e57-433e...@v25g2000yqk.googlegroups.com...
>> On Jan 23, 12:20 am, "Bob La Londe" <nos...@nospam.no> wrote:
>>> .... I offer them a job if I'm hiring
>>
>> What do you do?
>>
>> jsw
>
>I'm a communications contractor. Video, phone, data, access, alarm, sound,
>etc. A lot of related experience including aerial and underground
>applications. Licensed since 1994. Almost all learned on the job or self
>study. Education is in CIS and business.
>
>
I managed a similar company for 18 yrs. Too bad I didnt know you when
they split it up.