Two days ago I didn't know what they were and had never seen one before
(thanks to folks here for enlightening me). So today I installed my
first vacuum breaker (aka anti-siphon device) on a customer's hose bib.

It was something of a bitch. I noticed the setscrew on the new one I
bought, but couldn't see or feel any such screw on the old one, just a
round bump. So I just torqued the **** out of it with a pipe wrench
(crescent wrench holding the valve body). I threaded the new breaker on,
then tightened the setscrew. After just a few turns, it promptly broke
off, apparently just as it was designed to do (I could see it had a
narrow shank).

So what's the deal with these? Are you expected to replace the hose bib
and vacuum breaker as a unit when either one fails? After breaking off
the setscrew, there's no way in hell to get it out. (Wrenching it off
did chew up the threads some, but there was enough left to secure hold
the new breaker.)

The man at my plumbing supply place said he understood that inspectors
in Berkeley and Oakland were requiring these on new residential
construction (they're been required for commercial sites for some time now).


--
Washing one's hands of the conflict between the powerful and the
powerless means to side with the powerful, not to be neutral.

- Paulo Freire

On Thu 02 Oct 2008 09:25:32p, David Nebenzahl told us...

Two days ago I didn't know what they were and had never seen one before
(thanks to folks here for enlightening me). So today I installed my
first vacuum breaker (aka anti-siphon device) on a customer's hose bib.

It was something of a bitch. I noticed the setscrew on the new one I
bought, but couldn't see or feel any such screw on the old one, just a
round bump. So I just torqued the **** out of it with a pipe wrench
(crescent wrench holding the valve body). I threaded the new breaker on,
then tightened the setscrew. After just a few turns, it promptly broke
off, apparently just as it was designed to do (I could see it had a
narrow shank).

So what's the deal with these? Are you expected to replace the hose bib
and vacuum breaker as a unit when either one fails? After breaking off
the setscrew, there's no way in hell to get it out. (Wrenching it off
did chew up the threads some, but there was enough left to secure hold
the new breaker.)

The man at my plumbing supply place said he understood that inspectors
in Berkeley and Oakland were requiring these on new residential
construction (they're been required for commercial sites for some time
now).



They're required in the Phoenix area. The ones we have do have visible
set screws that appear can be removed. That's the only type I've seen.

--
Wayne Boatwright
(correct the spelling of "geemail" to reply)

*******************************************
Date: Thursday, 10(X)/02(II)/08(MMVIII)
*******************************************
Countdown till Veteran's Day
5wks 4dys 53mins
*******************************************
INTERLACE: To tie two boots together.
*******************************************

On 10/3/2008 3:58 AM spake thus:

On Thu, 02 Oct 2008 21:25:32 -0700, David Nebenzahl
wrote:

It was something of a bitch. I noticed the setscrew on the new one
I bought, but couldn't see or feel any such screw on the old one,
just a round bump. So I just torqued the **** out of it with a pipe
wrench (crescent wrench holding the valve body). I threaded the new
breaker on, then tightened the setscrew. After just a few turns, it
promptly broke off, apparently just as it was designed to do (I
could see it had a narrow shank).

I'd remove those set screws and use standard ones.

I probably will next time. But they're obviously made to snap off on
installation: why is that? (That bump I felt on the old one was the
shank of the broken setscrew.) Makes it really hard to remove them.

By the way, after testing it I could see why these are good things to
install: after turning on the hose bib and letting the hose reel fill
up, I closed the bib, whereupon a large gush of water sprayed out of the
anti-siphon valve. Had it not been there, all that water would have gone
back inside the house plumbing, along with whatever crap was in the hose
(or in a pool the hose was thrown into, in some cases).


--
Washing one's hands of the conflict between the powerful and the
powerless means to side with the powerful, not to be neutral.

- Paulo Freire

David Nebenzahl wrote:
....
I probably will next time. But they're obviously made to snap off on
installation: why is that? ...

So the average Joe can't remove them (guys like me, maybe??? )...it's
big brother Code run amok imo.

By the way, after testing it I could see why these are good things to
install: after turning on the hose bib and letting the hose reel fill
up, I closed the bib, whereupon a large gush of water sprayed out of the
anti-siphon valve. Had it not been there, all that water would have gone
back inside the house plumbing, along with whatever crap was in the hose
(or in a pool the hose was thrown into, in some cases).

How would that be if the the bib is close?

Only if there's some way to build higher pressure outside than in _and_
the valve is open is there any possibility of backflow. Those are
fairly rare circumstances in general--not impossible, but certainly not
all that common.

--

On 10/3/2008 10:24 AM dpb spake thus:

David Nebenzahl wrote:

By the way, after testing it I could see why these are good things
to install: after turning on the hose bib and letting the hose reel
fill up, I closed the bib, whereupon a large gush of water sprayed
out of the anti-siphon valve. Had it not been there, all that water
would have gone back inside the house plumbing, along with whatever
crap was in the hose (or in a pool the hose was thrown into, in
some cases).

How would that be if the the bib is close?

Right; duh. I should have written that *some* of that water *might* have
gone back inside the house. (A closed hose is basically a small
reservoir of water under pressure.)

Only if there's some way to build higher pressure outside than in _and_
the valve is open is there any possibility of backflow. Those are
fairly rare circumstances in general--not impossible, but certainly not
all that common.

Yep, probably true.


--
Washing one's hands of the conflict between the powerful and the
powerless means to side with the powerful, not to be neutral.

- Paulo Freire

David Nebenzahl wrote:
On 10/3/2008 10:24 AM dpb spake thus:

David Nebenzahl wrote:

By the way, after testing it I could see why these are good things
to install: after turning on the hose bib and letting the hose reel
fill up, I closed the bib, whereupon a large gush of water sprayed
out of the anti-siphon valve. Had it not been there, all that water
would have gone back inside the house plumbing, along with whatever
crap was in the hose (or in a pool the hose was thrown into, in
some cases).

How would that be if the the bib is close?

Right; duh. I should have written that *some* of that water *might* have
gone back inside the house. (A closed hose is basically a small
reservoir of water under pressure.)
....
But there's no pump there to build more pressure than the supply
pressure that filled it, hence no reverse flow.

If it is left out in the sun expansion will, of course build pressure,
but that is a very small volume even if the bib is subsequently opened
and the feed pipe is already full anyway. In very small volume any that
does manage to flow inward will be flushed immediately the hose is
opened and an open valve in the house would have to be in pretty special
location to cause the water in a stub supply line to be pulled inwards.

It's just not a common event imo...again, possible, granted but hardly a
major concern.

--

David Nebenzahl wrote:

On 10/3/2008 3:58 AM spake thus:

On Thu, 02 Oct 2008 21:25:32 -0700, David Nebenzahl
wrote:

It was something of a bitch. I noticed the setscrew on the new one
I bought, but couldn't see or feel any such screw on the old one,
just a round bump. So I just torqued the **** out of it with a pipe
wrench (crescent wrench holding the valve body). I threaded the new
breaker on, then tightened the setscrew. After just a few turns, it
promptly broke off, apparently just as it was designed to do (I
could see it had a narrow shank).

I'd remove those set screws and use standard ones.

I probably will next time. But they're obviously made to snap off on
installation: why is that? (That bump I felt on the old one was the
shank of the broken setscrew.) Makes it really hard to remove them.

By the way, after testing it I could see why these are good things to
install: after turning on the hose bib and letting the hose reel fill
up, I closed the bib, whereupon a large gush of water sprayed out of the
anti-siphon valve. Had it not been there, all that water would have gone
back inside the house plumbing, along with whatever crap was in the hose
(or in a pool the hose was thrown into, in some cases).

--
Washing one's hands of the conflict between the powerful and the
powerless means to side with the powerful, not to be neutral.

- Paulo Freire

David, if you live in an area where freezing occurs, you should install
that anti-siphon valve so that it can be removed from the hose bib
because it prevents the bib from being emptied of water even after the
hose is removed.

I use the kind of anti-siphon valve you're talking about and removed
that set-screw before installing it because tightening the set screw
prevents the valve from being unscrewed from the hose bib. I live in the
Midwest where freezing is a certainty.

On Oct 3, 12:25*am, David Nebenzahl wrote:
Two days ago I didn't know what they were and had never seen one before
(thanks to folks here for enlightening me). So today I installed my
first vacuum breaker (aka anti-siphon device) on a customer's hose bib.

It was something of a bitch. I noticed the setscrew on the new one I
bought, but couldn't see or feel any such screw on the old one, just a
round bump. So I just torqued the **** out of it with a pipe wrench
(crescent wrench holding the valve body). I threaded the new breaker on,
then tightened the setscrew. After just a few turns, it promptly broke
off, apparently just as it was designed to do (I could see it had a
narrow shank).

So what's the deal with these? Are you expected to replace the hose bib
and vacuum breaker as a unit when either one fails? After breaking off
the setscrew, there's no way in hell to get it out. (Wrenching it off
did chew up the threads some, but there was enough left to secure hold
the new breaker.)

The man at my plumbing supply place said he understood that inspectors
in Berkeley and Oakland were requiring these on new residential
construction (they're been required for commercial sites for some time now).

--
* Washing one's hands of the conflict between the powerful and the
powerless means to side with the powerful, not to be neutral.

- Paulo Freire

never occurred to me that the screw was designed to break off; i can
tell you that a year after being installed carefully so as to not
break the screw, if you try to uninstall it the screw breaks off,
though.

dpb wrote:

David Nebenzahl wrote:
On 10/3/2008 10:24 AM dpb spake thus:

David Nebenzahl wrote:

By the way, after testing it I could see why these are good
things to install: after turning on the hose bib and letting
the hose reel fill up, I closed the bib, whereupon a large gush
of water sprayed out of the anti-siphon valve. Had it not been
there, all that water would have gone back inside the house
plumbing, along with whatever crap was in the hose (or in a
pool the hose was thrown into, in some cases).

How would that be if the the bib is close?

Right; duh. I should have written that some of that water might
have gone back inside the house. (A closed hose is basically a
small reservoir of water under pressure.)
...
But there's no pump there to build more pressure than the supply
pressure that filled it, hence no reverse flow.

If it is left out in the sun expansion will, of course build
pressure, but that is a very small volume even if the bib is
subsequently opened and the feed pipe is already full anyway. In
very small volume any that does manage to flow inward will be
flushed immediately the hose is opened and an open valve in the house
would have to be in pretty special location to cause the water in a
stub supply line to be pulled inwards.

It's just not a common event imo...again, possible, granted but
hardly a major concern.

The code-hawks are worried about the case where the city shuts off your
water, be it because of maintenance, a broken line, or terrorist
activity. If you have your hose running in the pool when that happens,
and you're at the top of a hill (or just higher than the water main in
some cases) water could be sucked out of your pool and into the main.

You're right; it isn't a common event, but it has a non-zero
probability.

--
Steve Bell
New Life Home Improvement
Arlington, TX

SteveBell wrote:
....
You're right; it isn't a common event, but it has a non-zero
probability.

And combining the low probability of occurrence w/ the likelihood of
significant consequence as to be virtually nonsensical to worry about.

--

The bad news is that in Cary NC a couple of years ago, everyone had to use
bottled water due to contamination by bad plumbing at one house.


"dpb" wrote in message ...
SteveBell wrote:
...
You're right; it isn't a common event, but it has a non-zero
probability.

And combining the low probability of occurrence w/ the likelihood of
significant consequence as to be virtually nonsensical to worry about.

--

Art wrote:

"dpb" wrote in message ...
SteveBell wrote:
...
You're right; it isn't a common event, but it has a non-zero
probability.

And combining the low probability of occurrence w/ the likelihood
of significant consequence as to be virtually nonsensical to worry
about.

The bad news is that in Cary NC a couple of years ago, everyone had
to use bottled water due to contamination by bad plumbing at one
house.

That would be the non-zero part of the problem.

The hose in the pool is really low-danger. The guy spraying for bugs
with a hose-end sprayer is more of a danger. A little extra chlorine or
algae won't cause much havoc. A dose of insecticide in the water main
has a much larger negative potential.

--
Steve Bell
New Life Home Improvement
Arlington, TX

Art wrote:
The bad news is that in Cary NC a couple of years ago, everyone had to use
bottled water due to contamination by bad plumbing at one house.
....
I looked it up -- that was owing to the City/Wake County mistakenly
connecting treated sewage water to the supply lines. Nothing whatsoever
a hose bib vacuum breaker is going to to against that.

I stand by my previous assertion it's a nearly non-existent problem--in
fact, I'd be interested if anyone could find a single documented
incident of any significance.

--

On Oct 4, 10:08*pm, "SteveBell"
wrote:
Art wrote:
"dpb" wrote in ...
SteveBell wrote:
...
You're right; it isn't a common event, but it has a non-zero
probability.

And combining the low probability of occurrence w/ the likelihood
of *significant consequence as to be virtually nonsensical to worry
about.

The bad news is that in Cary NC a couple of years ago, everyone had
to use bottled water due to contamination by bad plumbing at one
house.

That would be the non-zero part of the problem.

The hose in the pool is really low-danger. The guy spraying for bugs
with a hose-end sprayer is more of a danger. A little extra chlorine or
algae won't cause much havoc. A dose of insecticide in the water main
has a much larger negative potential.

--
Steve Bell
New Life Home Improvement
Arlington, TX

well, i got my hose bibs hooked up to underground soaker hoses, and
that's most definitely vacuum breaker territory for me.

On Oct 3, 2:44*pm, Erma1ina wrote:

David, if you live in an area where freezing occurs, you should install
that anti-siphon valve so that it can be removed from the hose bib
because it prevents the bib from being emptied of water even after the
hose is removed.

I use the kind of anti-siphon valve you're talking about and removed
that set-screw before installing it because tightening the set screw
prevents the valve from being unscrewed from the hose bib. I live in the
Midwest where freezing is a certainty.- Hide quoted text -

- Show quoted text -

hmmmm..... as i posted boringly a while back, i just replaced a
freezeproof faucet which sure looked like it had frozen itself apart
inside the wall between the fall and the spring; copper tube bulged
out and finally ripped open a couple of inches long. I was assuming
that it had been installed at a tilt so it didn't drain completely,
but now that you mention it, i did install a vacuum breaker on it (see
my last post about underground soaker hoses); maybe that was the
killer. I note that all the replacements available now have the vacuum
breaker builtin, but it doesn't look like it's in series with the
water path.

z wrote:
....

well, i got my hose bibs hooked up to underground soaker hoses, and
that's most definitely vacuum breaker territory for me.

But do you frequently somehow manage to have lower pressure on the
upstream side of those bibs? Except in exceedingly rare events, it's
hard to conceive how that would be so. And, of course, once the soaker
hoses are turned off there's nowhere for it to go, either.

Not that they're not a safety precaution that makes some sense for the
application, but I'm still having difficulty figuring out a real high
likelihood, high consequence scenario that would seem to justify a
mandate for them on all outside faucets.

We've got a significant number of feet of soaker hose and other outside
irrigation and livestock operations but somehow the postulated doomsday
scenario hasn't occurred in nearly 100 years of farm operation.

--

On Oct 6, 1:35*pm, dpb wrote:
z wrote:

...

well, i got my hose bibs hooked up to underground soaker hoses, and
that's most definitely vacuum breaker territory for me.

But do you frequently somehow manage to have lower pressure on the
upstream side of those bibs? *Except in exceedingly rare events, it's
hard to conceive how that would be so. *And, of course, once the soaker
hoses are turned off there's nowhere for it to go, either.

Not that they're not a safety precaution that makes some sense for the
application, but I'm still having difficulty figuring out a real high
likelihood, high consequence scenario that would seem to justify a
mandate for them on all outside faucets.

We've got a significant number of feet of soaker hose and other outside
irrigation and livestock operations but somehow the postulated doomsday
scenario hasn't occurred in nearly 100 years of farm operation.

--

oh sure, the only way it could happen is if somebody turned off the
mains, and opened a tap downstairs, and one of the hose bibs did
indeed allow inward suction when it was shut off. but that's not a
completely impossible state of affairs. rare, yes, and something i
myself would probably not do, but the effort involved in remediating
the risk wouldn't seem to be too high with respect to the degree of
risk and the pain in the ass represented by trying to fix the
situation if it happened.