Ask Caleffi
Ask Caleffi
#22 5 Things You Need to Know About Why Your PRV Screams (with Cody Mack)
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A return guest joins Greg and Dan during this Episode: Cody Mack, Caleffi training and education manager. They get right to the point as they dig into perplexing PRV behavior. You'll learn:
1. Got noise? How to size a PRV CORRECTLY.
2. Step down pressure and how to manage.
3. PRV maintenance
4. PRV configurations
5. Familiar with 5 Things You Need To Know? Check it out on YouTube!
Thanks for joining us today.
Want to hear YOUR QUESTION on Ask Caleffi? Take this quick 4 question survey for your chance to hear your question in a future episode.
00:06
welcome to ask Caleffi the podcast that
00:09
dives into real life problems that
00:10
plumbing and hvac technicians face in
00:13
the field we're your hosts from the
00:14
Caleffi tech support team i'm greg tubbs
00:17
and i'm dan ferkus welcome we look
00:19
forward to sharing some stories from our
00:21
tech calls and using our background and
00:23
expertise to make your days a little
00:25
easier
00:26
[Music]
00:30
hey folks welcome back to another
00:32
episode of the ask caleffi podcast
00:36
greg here coming at you with
00:38
my buddy dan yeah we're back
00:41
we got a returning guest we do we're
00:43
pretty excited yeah you're lucky i came
00:45
back oh
00:47
someone just said you're lucky we let
00:48
you back
00:52
there you go
00:55
yeah sitting here in the studio with
00:57
bunsen and beaker
00:59
it's real funny isn't it yeah yeah if
01:02
you guys could be uh sesame street
01:04
characters i got bunsen and i got
01:07
beakers uh here we go i'm i'm beaker by
01:09
the way
01:13
and for those of you that don't know our
01:15
guest is cody mack our training and
01:17
education manager
01:20
yeah thanks for having me guys it's good
01:22
to be back um yeah
01:24
we're going to talk another five things
01:26
you need to know yeah another five
01:27
things we might even find a sixth thing
01:29
while we're at it okay maybe hold on a
01:31
little bonus yeah yeah so cody's here to
01:34
talk more about his series the five
01:36
things you need to know
01:38
yeah so yeah i mean you know it's a big
01:39
training initiative and we talked about
01:41
it last time the the fact that you know
01:42
we're trying to get stuff that's real
01:44
concise to the point and get that
01:46
information out to everybody that needs
01:48
it as quickly and easily as possible and
01:50
and i mentioned it before you know
01:52
attention spans are growing shorter and
01:54
shorter and so we're trying to keep
01:55
these videos really short with the five
01:57
things you need to know series and uh
01:59
you know usually they're about five
02:00
minutes give or take a little bit you
02:02
know um but again very straight to the
02:04
point very concise and uh gets you guys
02:06
uh the information you need cool we're
02:08
going to talk noisy prvs today aren't we
02:11
pressure reducing valves yeah not
02:13
pressure relief valves if those are
02:15
noisy you got a really big problem right
02:16
pressure reducing valves is what we're
02:18
going to talk about one of those makes a
02:19
noise louder than a drip you got a major
02:21
problem yeah oh yeah definitely a
02:22
popular phone call here at the ask
02:24
fluffy line yeah yeah here at cleffy you
02:27
know you know we've been really diving
02:29
pretty hard into the plumbing product
02:31
and and pressure reducing valves we've
02:32
had them for i don't know three four
02:34
years now it's been a while easily i
02:35
mean well we've always had the autofill
02:38
right so that's the pressure that's a
02:39
prv yeah for boiler systems you got it
02:41
yep yep but you usually don't hear a
02:43
problem with noise going through that
02:45
correct yeah that's usually kind of a
02:47
one and done kind of deal you know they
02:48
fill up the boiler and and if the prv is
02:50
still working chances are you got bigger
02:52
problems on the boiler system but but
02:54
you know like with with a pressure
02:55
reducing valve for you know potable
02:57
water that's a whole different ball you
02:59
know so kalefi italy they came out with
03:01
these prvs a number of years ago as a
03:04
global initiative so these these prvs uh
03:06
you can go all around the world and you
03:08
can see prvs that look exactly the same
03:09
from calefi which i think is really
03:11
really cool
03:12
but uh we you know we do
03:14
i'm not gonna
03:16
i'm not going to sugarcoat it we get
03:18
calls about them because you know the
03:19
things happen and uh and that's what
03:21
we're here you know you guys especially
03:23
you know you guys are taking the brunt
03:25
of most of the tech support calls you
03:27
guys do a fantastic job thanks but uh
03:29
i'm not you greg danny
03:32
back
03:34
back in the corner
03:35
oh yeah i'll shun you every time where's
03:38
that womp
03:39
right yeah
03:41
but anyways uh no so so we get some
03:44
calls about them you know and and
03:47
i say particularly with prvs it's it's
03:49
usually noise issues and and uh you know
03:52
uh so we we get some calls about them
03:54
and i think we've got some great
03:55
information in this particular five
03:57
things you need to know about
03:58
a little video that we can talk about
04:00
today you know um i guess what do you
04:03
guys want to start with
04:05
well we know one of the biggest things
04:07
is a valve being undersized or oversized
04:10
yeah yeah yeah selections bigger is not
04:13
always better you mean right right or
04:16
smaller better
04:17
you tell me where's goldilocks i think
04:19
you just size it based on pipe size
04:21
don't you oh man boy you just made life
04:24
so much easier for every contractor out
04:26
there the way you do
04:32
if it was that easy i don't think we
04:34
would have jobs gentlemen right he
04:36
packing it up hitting the road no i mean
04:38
we get that question a lot and
04:40
unfortunately it comes after the fact
04:43
that it's been installed
04:45
oh yeah and then you start reverse
04:47
engineering
04:49
what size pipe you have how big is the
04:51
house what kind of demand do you have on
04:53
right
04:54
oh
04:54
oh oops
04:56
yeah we didn't we didn't know you know
04:58
one inch one inch valve one inch pipe
05:00
should be able to install it walk away
05:02
and all good right not always the case
05:04
yeah we we get a number of calls i would
05:06
say on the regular where you know as far
05:09
as valves being oversized i mean for one
05:11
thing you're paying more for a valve
05:12
that you don't need you know um yeah i
05:14
mean we get plenty of calls where
05:16
they've got a three-quarter inch prv and
05:17
they could have used a half-inch prv and
05:19
then just fine you know you get a
05:20
single-family residential you don't have
05:22
any of the giant raining shower heads
05:24
and all that other fun stuff or or the
05:26
six gallon per flush toilets and and you
05:28
know um irrigation systems yeah or
05:31
irrigation systems whatever yeah and so
05:34
i mean
05:35
getting that valve to the proper size i
05:37
think is is really important i think
05:39
i didn't even mention it in my five
05:40
things you need to know video but there
05:41
are some great uh water demand
05:43
calculators out there the one that i'm
05:44
thinking of
05:46
is uh is from iapmo and iatmo has a
05:49
water demand calculator out there to
05:51
where you can actually plug in for i
05:53
believe it's single-family residential
05:54
or multi-family residential but you can
05:56
plug in all your fixtures into that and
05:58
it'll give you a demand for for potable
06:02
water which is fantastic you know and
06:04
you can figure out exactly what you need
06:06
um you know
06:07
obviously it'll get you in the ballpark
06:09
it might not be you know 100 but it'll
06:11
get you to 90 as opposed to just a wild
06:14
guess you know right exactly yeah
06:17
sometimes it's hard to get guys to wrap
06:18
their mind around the fact that you know
06:20
what it might be three quarter inch
06:22
coming into the home or or one inch but
06:24
you're stepping down one or two sizes
06:26
with your prv yep but again sizing more
06:28
based on the demand absolutely
06:31
yeah so yeah definitely uh i think
06:34
that's probably the biggest thing that
06:35
we get calls about is either undersized
06:37
or oversized um you know uh whether
06:40
whether again whether they be undersized
06:42
or oversized you get that undersized
06:43
scenario which
06:45
uh you know let's be honest that doesn't
06:46
happen you know usually undersizing is
06:48
not that much of an issue but if it is
06:50
undersized you know you get too much
06:51
flow through through that guy you get a
06:53
lot of velocity you're going to get a
06:54
lot of noise and everything like that
06:56
but on the oversized uh end of the
06:58
spectrum
06:59
you're you're not working within the
07:01
good control range of that pressure
07:02
reducing valve and so that that prv um
07:05
it has the ability to allow a lot of
07:07
flow through at one time well if you're
07:09
just running you know small fixtures uh
07:11
single family residential you know that
07:13
prv is going to say for example you got
07:15
a small powder room sink on or something
07:17
like that that prv is going to open and
07:19
close really fast because it's going to
07:20
hit that pressure mark and it's going to
07:22
want to shut off so that's going to lead
07:23
to some chattering or some thumping or
07:25
vibrating of the pipe vibrating of pipes
07:28
and things like that so it's you know
07:30
it's it's really important to get these
07:32
sized properly and and you know it's
07:34
kind of a blessing and a curse the fact
07:36
that the khalefi prvs we have the
07:38
ability to flow so much through these
07:40
prvs uh compared to a lot of our
07:42
competitors that is something that you
07:44
just need to be aware of right
07:47
yep that's for sure the other thing
07:48
would be your pressure range and and how
07:50
you're adjusting your your pressure
07:53
your step down pressure right for sure
07:55
yeah yeah we we get that call quite a
07:58
bit um you know we we talk about it
08:00
frequently
08:01
if you've got a big differential between
08:03
inlet outlet man that can you know say
08:06
you got 250 psi coming into a building
08:08
for one thing you know there are certain
08:10
particular uh even prvs that you know we
08:13
do have a pressure range on the inlet
08:15
side you can you know as far as going
08:16
too high but if you're trying to take it
08:18
from 200 down to 50 you've got a ratio
08:21
of four to one inlet to outlet that is
08:23
really high and and so
08:25
it doesn't take a lot uh of of uh flow
08:28
going through that valve in order again
08:30
to bring that pressure back up and so uh
08:32
you know usually we recommend two to one
08:35
sometimes up to three to one give or
08:36
take a little bit but the closer you
08:38
start getting to that three to one range
08:39
that's where you're gonna start running
08:41
into more noise issues for sure yeah i
08:43
actually took a call the other day
08:45
about something similar to that it was
08:47
making noise
08:48
and they were closer they were just over
08:50
the two to one closer to three to one it
08:53
was working but it was noisy
08:56
so they're like well you think it's a
08:57
bad prv i'm like you might be getting
09:00
close to that threshold where yeah
09:01
you're gonna hear some noise
09:03
now here's a really fun fact
09:06
if you do have that huge drop in
09:08
pressure say you live in a mountainous
09:09
area you got a lot of elevation things
09:11
like that and you need to bring it down
09:13
from you know you know 200 or more down
09:15
to 50 or 60 or whatever
09:18
as contractors this is your opportunity
09:20
to not sell one prv but two prvs and two
09:24
funny thing you mentioned that because i
09:26
took a call about that last week yeah
09:28
and it was the same situation well in
09:30
the mountain it's coming down the
09:32
mountains building pressure yeah and
09:34
they had single prvs from a competitor i
09:37
won't mention names of and they were
09:39
they were only last in three months yep
09:41
and they were going out yeah and so and
09:43
so you know the idea with two prvs well
09:45
how how on earth do you do you pipe up
09:47
two prvs to make this all happen you
09:49
actually just pipe them in series
09:50
literally one right after the other and
09:52
you create a staging
09:54
type of scenario to where that first prv
09:56
you know might take it from 200 down to
09:58
100 or 200 down to 120 and then the
10:00
second one takes it from 120 to 60 or 70
10:03
or whatever the case may be
10:05
and now you've got this staging scenario
10:07
to where it's not just one valve taking
10:09
the brunt of the work and and again this
10:11
isn't you know this isn't a calefi issue
10:12
this is every prv issue you know every
10:15
pressure reducing valve that's out there
10:16
is going to have these same kind of
10:18
scenarios or or potential rules and so
10:21
again if you've got that opportunity i
10:23
mean you're doing right by the customer
10:25
sell them two prvs you can make a little
10:27
bit more money the customer is going to
10:28
have a system that works really really
10:30
well and everybody's going to be happy
10:32
very good exactly
10:34
yeah
10:35
now i would say the other big one that
10:38
we get a lot of calls about is uh dirty
10:41
prvs yeah dirty povs now
10:44
despite greg i know you do a lot of jobs
10:47
here at gallefy but do you add dirt to
10:49
the pressure reducing valves before we
10:50
send them out
10:51
or is that dan's job no i think that's
10:53
dan's job no no okay all right
10:55
somebody must get paid because uh you
10:57
know it's one of those things where we
10:58
get i've got this brand new prv
11:00
installed and everything like that and
11:02
then and uh you know
11:04
there's there's certain symptoms that
11:06
come along with dirty prvs what do you
11:07
guys run into yeah so
11:09
i can kind of say that all three of us
11:12
here
11:13
sitting at this table talking into these
11:15
microphones have gotten packages back
11:17
addressed to us saying prvs are they
11:20
care packages right they're definitely
11:21
not carrying are they
11:23
no it's not and we crack them open and
11:26
there's prvs in there and we don't even
11:28
get the cartridge out of them and
11:30
there's debris falling yeah yeah you can
11:31
see chunks of solder in there chunks of
11:33
solder rust
11:35
yeah ferrous material i mean threading
11:38
tape yeah there's a lot of different
11:40
things sand
11:41
but it makes it through that filter
11:43
screen that's in there
11:44
and it's it's not even in the filter
11:47
screen it's actually in the bottom of
11:48
that cartridge right right where that
11:50
it's right in the seat yeah right where
11:52
it closes off well if you've got a
11:54
pebble or something in there just a
11:55
little chunk of copper can do it yeah
11:57
yeah and it does have shavings it's a
11:59
very small fine surface area that it
12:01
needs to be able to pinch off and if it
12:04
can't because of a little piece of
12:05
copper grits of sand or whatever it is
12:08
it's it's going to allow that system
12:10
pressure to creep up right or cause
12:13
noise yeah and i think that's one thing
12:15
that our prv does really really well is
12:17
that we do have a screen that goes
12:18
around the entire cartridge it's a 360
12:21
degree screen as opposed to a lot of our
12:23
competitors that just have a screen at
12:24
the inlet that's you know three quarters
12:26
of an inch in diameter or whatever but
12:28
you know obviously the screen is only
12:30
going to catch the stuff that's bigger
12:31
than the holes in the screen right so if
12:33
you've got dirt and debris that gets
12:34
past there
12:35
what's going to end up happening is the
12:37
dirt and debris is going to prevent that
12:38
cartridge from closing off and so during
12:41
times of little to no demand you're
12:43
going to start to see a rise in pressure
12:45
and you're going to think well that prv
12:46
is not controlling it must be bad you
12:48
know and and then you're going to send
12:51
greg a care package because he loves
12:52
care packages and and uh and then we're
12:54
gonna open it up and we're gonna clean
12:55
it we're gonna put it in the lab and the
12:56
thing's gonna work like a million bucks
12:58
right and so yeah definitely i mean it's
13:00
something to consider you know as far as
13:02
upstream strainers or media filters uh
13:04
going into the home or the business or
13:06
whatever the case may be but
13:08
just remember
13:09
our prvs you can take them apart so
13:11
easily and clean them out and put them
13:13
back into service uh you know when we
13:15
test these when they come back we put
13:17
them in the lab and put them on the wall
13:18
they don't work they creep up you know
13:20
they do that
13:21
we pull the cartridge we clean them out
13:23
and and they're back up and running
13:24
beautifully in like five minutes yeah
13:27
it's so easy yeah it's pretty quick and
13:29
with that cartridge it's so easy to just
13:31
throw it out it's easy to yeah room pull
13:33
it out and clean it flush it out and but
13:35
it's it's also just as easy if you had a
13:38
spare cartridge which we do sell
13:40
to do a cartridge replacement if you
13:42
really had to yeah if they're really
13:43
gummed up yet yeah or if something's
13:45
wearing out in it but that's going to be
13:47
over time yep
13:49
so yeah there's there's a number of
13:50
things you know um
13:52
you know
13:53
one thing that wasn't really even part
13:54
of uh my five things particular video
13:56
but i think is something that needs to
13:58
be addressed is um whenever you have a
14:00
prv in the in the circuit or coming into
14:02
the home that's it's it's not really
14:04
meant to be but it does act as a bit of
14:06
a check valve have you guys run into
14:08
that before yes yeah yeah sure yep
14:11
my uh that's that's a
14:13
pretty good phone call that we get why
14:16
why is my system pressure creeping up
14:18
and now my pressure relief valve on my
14:21
hot water tank is yeah it didn't do that
14:23
before the prv yeah and then yeah we
14:26
don't have the old school technology
14:28
where it's allowing water to push back
14:30
but hey wait a second though like okay
14:32
so so you brought up a great point greg
14:34
there there are some manufacturers out
14:36
there that in their pressure reducing
14:37
valve have what's called a bypass valve
14:40
and so with most pressure reducing
14:41
valves water can flow through in one
14:43
direction and the idea is that it
14:44
doesn't go backwards and it's not meant
14:46
to be that way it's not meant to be a
14:48
check valve but that's just what happens
14:50
but
14:51
some of our competitors do have a bypass
14:53
valve and that bypass valve i think is
14:54
really important to note that it's i
14:57
think it's a terrible idea for one thing
14:59
okay
15:00
and so this bypass valve the idea is
15:02
that if the downstream pressure of the
15:04
valve is more than the upstream pressure
15:06
the bypass valve allows it to go
15:07
backwards
15:08
uh can you name off on your hand greg
15:11
how many or dan or what water
15:13
municipalities that want water back
15:15
after it's entered your house
15:17
not a one are you sure yeah i mean come
15:20
on who wouldn't want the water back
15:21
after it's been in my house and so is
15:23
there a buyback program on it there you
15:25
go yeah
15:26
now you're on to something yeah we'll
15:28
have to look into that uh but the idea
15:30
is you know a lot of these
15:32
municipalities are required it's
15:33
considered contaminated contaminated
15:35
yeah they don't want it back and so you
15:38
know a lot of places are requiring
15:39
backflow prevention going into homes and
15:41
businesses and and and things like that
15:42
whether it be double checks dual checks
15:45
rpg type stuff but a prv can act as this
15:48
too and and so if you have a prv in
15:50
place
15:51
and it's not dirty like what we talked
15:52
about before but chances are you're also
15:54
going to have a domestic hot water
15:55
source which as we all know when you
15:57
heat water what happens it spans it
16:00
expands it's going to want to increase
16:01
the pressure and so you need to have an
16:04
expansion tank so if you're
16:06
this is another great cell technique for
16:08
you guys not only did we we talk about
16:10
you know two prvs uh you if you're
16:13
selling a prv it's never had a prv in
16:14
place before definitely look into an
16:16
expansion tank as well absolutely
16:18
water's gotta have somewhere to go it
16:19
does it's not gonna blow your pipes up
16:22
like a balloon it's got to have a place
16:24
to expand so
16:26
put that or you can sell them a bucket
16:28
to put it on the relief valve on the
16:30
water heater
16:31
there you go you can get a custom
16:32
branded bucket with your company name on
16:34
it
16:35
yeah it's it's there's we get a lot of
16:36
interesting calls you know i mean uh
16:38
pressure reducing valves are are an
16:40
interesting one and and you know greg
16:42
you talked about it before as far as
16:43
undersizing and over sizing and and you
16:44
always need to make sure the valve is
16:46
sized to to meet the maximum demand okay
16:50
but the other thing that you kind of run
16:52
into is that if if you size a prv to to
16:54
meet the maximum demand um that prv in
16:57
particular might not be the best prv to
16:59
handle that little itty bitty load from
17:01
you know a small bathroom sink like a
17:03
half a gpm or whatever right and um
17:07
and so it's something
17:08
something that you got to be aware of um
17:10
the fact that you know a big prv is
17:12
great for that that high capacity or
17:14
that that that design day if you want to
17:17
call it that but
17:19
but for that guy that's just trying to
17:20
wash his hands in the middle of the
17:21
night it might not be your best scenario
17:23
uh have you guys ever run into that
17:24
before oh yeah definitely yeah yeah i
17:27
mean you you know one thing we look at
17:29
is we always recommend sizing between
17:31
that three to six feet per second range
17:33
so totaling up your load looking at the
17:35
flow characteristic chart and picking
17:37
the model that fits within that three to
17:39
six feet per second
17:41
minimum flow rates what we recommend is
17:44
really down to one foot per second yep
17:45
so it's not uncommon i mean you look at
17:48
our one inch valve that's got a high
17:50
flow capacity it's 10 to 19 gpm right
17:52
but at one foot per second it's still
17:55
looking for it's still able to deliver
17:57
about three three gallons per minute
17:58
yeah that's pretty crazy yeah so i mean
18:01
you know obviously most of your bathroom
18:03
sinks and whatnot are not gonna be three
18:04
gallons per minute
18:06
and uh you know in a lot of scenarios it
18:07
can work pretty stably under that one
18:09
feet per second velocity range but
18:10
that's kind of the recommendation
18:12
but if you do have a scenario where
18:14
you've got a high flow demand and
18:16
everything like that again you need to
18:17
size that big prv to handle that but
18:20
this is another scenario ding ding ding
18:21
ding ding you can sell two prvs this is
18:24
really awesome and instead of a staging
18:26
type scenario you're gonna actually run
18:27
it in a high low scenario so you're
18:29
gonna have a big prv that handles that
18:31
that big load uh when everything's on uh
18:34
the design day so to speak but then
18:35
you're gonna have a smaller prv that's
18:37
actually piped in parallel to the bigger
18:39
prv and you're gonna set that smaller
18:41
prv to a slightly higher pressure
18:44
so that way when there is a drop on the
18:46
the distribution system that small prv
18:48
is going to pick it up and and you know
18:50
replenish but then if the pressure drop
18:52
gets too great then that bigger prv in
18:55
parallel will open up and it will kind
18:56
of take it over from there so so it is a
18:59
parallel type thing it is also it's a
19:01
nice redundancy thing too i mean it is
19:03
if you ever need to service them clean
19:04
them out or anything you don't have to
19:05
take down the whole building um and not
19:07
only this i mean two in parallel is one
19:09
thing if you've got a big enough demand
19:10
you can do multiple
19:11
two three four four yeah in parallel
19:14
depending on the size and the need for
19:15
the building and everything like that so
19:17
so again something to think about there
19:18
with prvs sizing is super important
19:21
though i mean good grief maybe
19:23
sizing is super
19:25
yeah i mean that's the majority of our
19:26
calls the problems is it wasn't sized
19:28
correctly to begin with yeah yeah when
19:30
it comes to noise the sizing is is
19:33
pretty important the parallel pipe thing
19:35
is great i mean especially for larger
19:37
homes with multiple different
19:40
sizes of varying loads with uh
19:43
irrigation systems we see a lot of that
19:45
with irrigation systems i've had i don't
19:47
know how many guys call me yeah i got an
19:49
irrigation system they got a prv but i
19:50
don't think you can keep up well this is
19:52
what you have to do right now so you
19:54
talk them through parallel piping a
19:56
bigger one and then smaller ones or a
19:58
smaller one and it works out great for
20:00
them and never hear back from them right
20:02
for sure
20:04
yeah so you know ed khalefi you know
20:06
like i said we've we've had these prbs
20:07
for a few years we've been doing
20:08
fantastic with them um you know if you
20:11
guys ever have questions you know don't
20:13
hesitate to reach out to us we've got a
20:14
lot of great resources available online
20:16
you know with uh with a lot of our
20:18
webinars on youtube but uh we've got
20:21
some great people like lefty here too um
20:24
yeah we're always happy to help yeah we
20:26
pride ourselves on being able to help
20:27
everybody out in the field yeah yeah so
20:29
we're happy you could join us again
20:30
today cody and promote your five things
20:32
you need to know series you guys can
20:34
check that out um on our youtube channel
20:36
or yeah all the social media social
20:38
media yeah check anywhere you can find
20:40
kolofi you can find that
20:42
all right thanks for having me guys i
20:43
really appreciate it alright great
20:44
thanks cody
20:46
thank you for tuning in if you ever need
20:48
help please feel free to contact our
20:50
tech support team anytime at
20:52
techsupport.us
20:55
caleffi.com
20:57
or call us during our business hours at
21:00
7 30
21:01
to 4 30 pm
21:03
central time
21:04
at 414-238-2360
21:14
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