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Ask Caleffi
#15 "I'm looking for a mixing valve. What kind of valve do I need?"
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Greg and Dan are behind-the-mic to discuss why you may want to select an electronic mixing valve for your next application. They discuss how this digital valve is different from a thermostatic valve. Why would you install a valve like this? How about trouble-shooting... will a digital valve make a difference in problem resolution? "This valve is electronic... wires are involved for installation. I'm a plumber. Helpl!" Our Ask Caleffi team offers plumber-friendly installation tips! Thermal disinfection? Anti-scald? Now you're talking! Thanks for tuning in.
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[Music]
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welcome to ask Caleffi
00:07
the podcast that dives into real-life
00:10
problems that plumbing and hvac
00:11
technicians face in the field
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we're your hosts from the Caleffi tech
00:15
support team i'm greg tubbs
00:17
and i'm dan firkis welcome we look
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forward to sharing some stories from our
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tech
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calls and using our background and
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expertise to make your days a little
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easier
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hey there folks welcome back we are here
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today
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episode 15 talking about the LegioMix
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yeah electronic mixing valves the legiomix
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absolutely yeah welcome back everybody
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so
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we get this a lot hey i'm looking for a
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mixing valve
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what do you have for me you know and we
00:49
asked the question
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what is your application or what product
00:54
do you want me to cross it to
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many times it's either a large
00:58
electronic from another company
00:59
yeah or large thermostatic from another
01:01
company or a high low assembly yeah high
01:03
lows
01:04
i mean they're expensive and a lot of
01:06
times when we're getting this phone call
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it's because they're replacing either a
01:11
high low or a thermostat right or
01:12
they're
01:12
trying to rebuild one they're in the
01:14
maybe in the process of rebuilding one
01:16
they price out the parts and they go man
01:18
that's really expensive right
01:21
yeah absolutely so
01:24
why do we use one it's a motorized ball
01:26
valve versus a thermostatic cartridge
01:28
type
01:28
right absolutely it's a electronic
01:31
control with
01:32
a sensor in the mixed outlet to measure
01:34
your temperature versus that
01:35
thermostatic cartridge
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yeah so it's going to give you a higher
01:39
maximum flow rate
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and in some cases a lower minimum flow
01:44
rate yeah most cases
01:45
yeah depending on the application and
01:48
what you really need
01:49
right right yeah and you know what that
01:52
with that three-way ball valve that we
01:54
have it's going to be less maintenance
01:56
as well
01:56
it certainly is you start looking at all
01:58
the shutters and springs and
02:00
thermostatic element you know in
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comparison to a three-way ball valve
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that's gonna
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it's gonna be less maintenance for you
02:06
absolutely they're more accurate
02:09
they display real-time information right
02:12
there on the control
02:14
yeah has the ability to send you an
02:15
error code in the event of a failure
02:19
sure it stores data um you know
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it logs 40 days where the history and it
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has a battery backup
02:27
in fact we had a company put one in
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and they were having some trouble in the
02:34
system
02:36
weren't they they were yeah they
02:39
they called us and basically what
02:42
happened was one of the one of the
02:45
system pumps went down
02:46
yeah well it was interesting i i that
02:48
was a tech call i took so
02:50
i remember talking to the technician on
02:52
site and
02:53
you know he i said okay well so you
02:57
what was the initial call okay the
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initial call was you know we're losing
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hot water
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okay okay is the system working now
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he's like yeah it's working it's working
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great it's been working great for
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almost a year since we put it in and he
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said suddenly we had a call two days in
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a row that they lost hot water
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and i said okay well that's interesting
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i said but it's back and it's working
03:27
now it is i said well let's go into the
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data log
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i said that thing stores a 40-day data
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log
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of of water temperatures and it's great
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for
03:38
you know one to be able to monitor how
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the control is working
03:41
one for a liability issue should
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somebody you know ever have a suit or be
03:45
get scalded or complain that the weather
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was too hot or not hot enough
03:49
i said so let's jump into the log and
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see what the log says so
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two days in a row at 6 00 p.m
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the temperature dropped interesting and
04:00
then
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it stayed down for i believe it was
04:03
about an hour and a half or two hours
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and then went back to normal temperature
04:08
so weird
04:09
and it was 6 p.m so i said okay so two
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days in a row
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at 6 00 p.m you lost hot water and
04:16
lost it for two hours and it came back
04:19
what's happening in the building at 6 00
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pm
04:22
sure so yeah they were able to track
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back to maintenance crews on site
04:27
and using i believe was a mop sink
04:31
and they were determining determining
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that they had a cross connection and
04:34
that was
04:35
that was affecting the performance sure
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so when the maintenance crew went in to
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say go fill buckets of water and
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do some cleaning this is when this
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occurred right
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crazy but but that history log was able
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to show them that
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sure and if it were tied into a building
04:54
automation system i mean there's a lot
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of different things you can do through a
04:58
building automation system right you
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know set it up through an alarm
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um monitor the system change the
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temperature
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all that yeah absolutely yeah and you
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can connect to the control with modbus
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directly to our control
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sure or with a modbus to backnet gateway
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you can
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convert and communicate in bacnet
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absolutely
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so that was uh
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pretty much the benefits of it
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installing this thing i mean that's
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where we
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start to get all sorts of questions
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that's where we tend to get a lot of
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calls is when the guys are installing it
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not
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not so much necessarily piping it
05:38
although we do get to get a fair amount
05:40
of
05:41
of calls regarding piping but more so
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when you get to the wiring and setup
05:46
yeah wiring setup are usually the
05:48
biggest hang-ups because let's be honest
05:49
if you're a plumber
05:50
you're not doing a whole lot of wiring
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in your in your days of field
05:54
you're doing more of the piping and and
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the delivery side
05:58
right so i can see where this can be
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a little bit menacing to some because
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you have this box you got to get voltage
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to it
06:10
and then once you get the voltage to it
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provided you get the right voltage to it
06:14
and it works it it wires in 24 volts we
06:18
provide a transformer with it
06:21
you have to set the thing up too yeah
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well it's stepping back to wiring i mean
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you talk about it doesn't get any easier
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than the legio mix to wire it so let's
06:30
look at it so you have your
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step down transformer that comes with
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the system yep it converts from
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you know a multiple voltage in inputs
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either
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240 yep uh 120 277
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it'll go up i think even as high as 408
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yeah
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down to 24 volts so no matter what
06:50
commercial
06:51
mechanical space you're working in you
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should be able to find a power source
06:54
where that can be connected
06:55
you may need an electrician to make the
06:57
high voltage connection but
06:58
from there it's 24 volts down to our
07:01
control
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right yep right in the terminal strips
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that plug right into the back of the
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control board
07:07
you know that terminals 9 through 15
07:10
that block as your line your neutral
07:13
and then your your four wires to go into
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your actuator right yep so you have
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so you have your input voltage and then
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you have your actuator yep the output
07:24
right and add that output voltage to
07:26
your actuator then from there you have a
07:28
mixed outlet sensor
07:30
and a return a return sensor yup return
07:33
sensor
07:34
so those guys
07:37
once once they're wired in you go into
07:39
the menu
07:40
this thing is set up right out of the
07:42
box to do basic electronic
07:44
mixing absolutely what's the number one
07:47
first thing you do when you open that
07:48
control up craig
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well this is a big one is that
07:53
that battery switch that gets a lot of
07:56
guys
07:56
that's that's another phone call we get
07:58
is hey i got an alarm on this thing
08:01
it says um alarm battery
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you got to flip that switch on so it can
08:06
start charging it
08:08
it takes about 36 hours to charge it
08:10
fully but
08:12
in a few hours that alarm will go away
08:15
and the valve will be working normally
08:18
now getting into the menu
08:21
you get into the setup menu and you have
08:25
a few adjustments to make don't we
08:27
you do yeah before you get into that um
08:30
what you'll do is you'll you'll get
08:31
everything wired you'll turn the battery
08:33
on like craig said
08:34
and then you'll energize that that ac
08:37
that control
08:38
you'll set up your time and your date
08:40
and you'll set up country of origin
08:42
which is usa
08:44
and then once you set that up the valve
08:47
is going to go into an anti-clog
08:48
function
08:49
and an anti-clock function takes
08:52
14 minutes to run and then
08:55
once that's done and what it's doing is
08:57
it's checking the the actuator
09:00
it's moving the ball rotating it all the
09:02
way hot all the way cold all the way hot
09:04
all the way cold it does that twice
09:07
and it does that to make sure that it's
09:08
free of free in operation that there's
09:10
no debris in it
09:11
right um once that is complete that's
09:14
when it's going to going to go into the
09:16
adjustment running mode and that's where
09:17
you'll jump in
09:18
and start making your changes sure
09:22
so set one temperature that would be our
09:24
mixed out with temperature
09:26
yes it would so right out of the box
09:29
we have it set to 113 degrees just in
09:31
case somebody
09:32
would somehow skip that which
09:35
very well could happen you know plumber
09:37
goes pipes it in
09:39
we do our job but the electrician hasn't
09:42
been there yet
09:43
electrician goes throws the juice to it
09:45
it fires up and starts doing its own
09:48
thing
09:48
the electrician walks away because he's
09:51
none the wiser to
09:52
what he's really supposed to power on
09:54
he's got power he did his part
09:56
it's it's either the building
09:57
maintenance guy's job
09:59
or the plumber's gonna have to come back
10:01
and do all the settings in it
10:03
so it's set to 113 degrees so when
10:05
people don't burn themselves
10:07
right yep it's a safe temperature yep
10:09
but then you would take
10:10
that temperature make your adjustment to
10:13
where you want it to be
10:14
and that's pretty much it for the
10:17
electronic mixing side of it
10:19
yeah if you're just going to do
10:20
temperature mixing right
10:22
but if you have a program
10:26
in mind where you want to be able to do
10:28
legionella control
10:30
then you're going to be making
10:32
adjustments to the set 2 and set 3
10:34
temperatures
10:36
right right yep and you're going to turn
10:37
on that legionella control
10:39
you know this this valve has the ability
10:41
to do thermal disinfection
10:43
and you can set up through the through
10:45
the program
10:47
how many days a week it's going to do
10:48
that what time of day
10:50
it's going to do that and what the
10:52
temperatures of the supply outlet
10:54
and the return outlet has to be so
10:57
you know it comes factory set up where
11:00
for thermal disinfection once you set
11:02
the days and times
11:04
becomes factory set for 2 a.m so from 2
11:07
to 3 a.m it's going to do thermal
11:09
disinfection
11:10
and it comes factory set up at 140
11:13
degree
11:14
outlet temperature with 135 degree
11:17
coming back on the return
11:19
so it's going to kick into thermal
11:21
disinfection mode
11:22
it's going to send 140 degree water out
11:25
through your hot
11:26
hot system looking for 135 degree
11:30
temperature on the return
11:31
for 30 minutes of that one hour cycle
11:34
and that is to ensure that you've killed
11:36
any legionella bacteria yep once it sees
11:39
that 135 on the return side for
11:42
30 minutes of that hour cycle it
11:44
determines that thermal disinfection has
11:46
been completed
11:47
sure so here's one for you
11:51
what if they decided that they wanted
11:53
150
11:54
delivered to the system during that that
11:57
particular program
11:59
they can change that you just jump into
12:00
the to the
12:02
set max and bump it up to
12:06
the 150. okay so
12:10
theoretically it would take less time to
12:13
disinfect a system at
12:14
higher temperature it will yeah and i
12:16
believe there's a chart in our
12:17
installation manual that'll show
12:20
you know based on you know the supply
12:22
temperature how long it takes to
12:24
complete the thermal disinfection cycle
12:26
gotcha so
12:30
going away from that there's also some
12:33
other
12:34
little tidbits in there auxiliary
12:38
relays for instance to be able to maybe
12:40
run a pump but
12:41
keep in mind these are dry contact right
12:43
yeah they're all dry contact
12:44
meaning that this control does not
12:45
provide voltage to those contacts
12:48
you have to provide 120 to power the
12:51
pump or
12:52
whatever voltage that pump runs off
12:54
right yeah depending on how your system
12:56
is designed
12:57
you know if you're doing thermal
12:58
disinfection you need the recirc pump
13:00
running
13:01
so you know we recommend running your
13:03
recirc pump all the time
13:04
right that you know you're probably
13:07
going to do that to make up your minimum
13:08
flow rates but
13:09
say your system is designed where
13:13
you know what your minimum flow rates
13:14
are made are already made up so you
13:16
don't need to run that recirc pump
13:18
continuously and you have it on an aqua
13:20
stat or on a timer
13:21
you can bypass that through the relay
13:24
and turn the pump on for thermal
13:25
disinfection
13:26
perfect and then we have that anti-clog
13:30
function too that's in there
13:32
yep and i've seen people kind of
13:35
get burned by that when their building
13:38
automation system has
13:40
you know some sort of safety put into it
13:43
to keep people from being scalded
13:45
because maybe they don't have anti-scald
13:48
right in that building now you should
13:51
have anti-scald especially if you are
13:53
doing
13:54
thermal disinfection yeah if you're
13:56
doing thermal disinfection you have to
13:57
have point of use mixing valves
13:59
anti-skull protection but if it is a
14:02
worry you can turn that anti-clog
14:04
off you can yup you can jump in and turn
14:07
it off i recommend leaving it on
14:09
and all that's gonna do is once a day
14:11
it's gonna it's gonna run an anti-clog
14:13
cycle i believe it's around around
14:16
midnight every day
14:17
unless you're doing thermal disinfection
14:20
where it's going to rotate the ball all
14:21
the way hot
14:22
all the way cold all the way hot all the
14:24
way cold takes again about 14 minutes to
14:26
complete
14:27
right and then returns back to a mix
14:29
mode so it tries to do it in the middle
14:31
of the night where the load's going to
14:32
be low
14:33
so you know if you don't have uh skull
14:35
protection in place
14:37
you know typically it's a short enough
14:38
period where you're okay
14:40
typically and the ball is moving right
14:42
so i mean it is changing temperature
14:44
throughout that yep and you'll see that
14:46
on the control
14:47
if you're a control watcher you'll watch
14:50
some of them oh yeah and go down how
14:54
about sizing
14:55
i mean pipe sizing is always really
14:57
critical on these isn't it
14:59
yeah pipe sizing well pipe sizing is
15:01
important in every application
15:02
you know one you know when you're sizing
15:04
the mixing valve you obviously want to
15:06
know your minimum and maximum
15:08
flow rates um like any product yo
15:11
don't size based on pipe size size based
15:13
on flow requirements
15:15
right typically that's an engineered
15:17
spec
15:18
and if you're in an old building you
15:20
might have to take a few steps back and
15:22
and really look at what you what your
15:24
demand would be right
15:26
right but then when you look at pipe
15:28
sizing um
15:29
it's not uncommon to see our piping or
15:32
our valves
15:33
piped with pipe connections coming to it
15:36
you know maybe
15:36
even twice the pipe size of the valve
15:39
yeah it's i don't know how many
15:41
applications i've seen they've uh you
15:43
know emailed us pictures of the install
15:46
and it's a one inch valve
15:47
in a system with two to two and a half
15:49
inch copper right yeah or three inch
15:51
right or two inch valves with four inch
15:53
copper coming to them
15:54
right and you're really doing that to
15:57
control the velocity in your piping
15:59
right the copper development association
16:02
and uniform plumbing codes they do not
16:06
they do not recommend exceeding five
16:08
feet per second in copper
16:09
right yep they don't allow that for
16:11
erosion corrosion to prevent erosion
16:13
corrosion or pinhole in your piping
16:15
right it just shortens the life of your
16:17
piping if you're running
16:19
too much velocity through it right so
16:21
that's where
16:22
you know you don't you look at a two
16:25
inch valve for example
16:26
you know our two inch valve will flow up
16:28
to 215 gallons per minute
16:30
yep but a two psi drop right but you try
16:33
to run that through two inch piping and
16:35
you're going to exceed that five feet
16:36
per second velocity
16:38
very much so so that's where you know
16:40
you may have to size up to like four
16:42
inch copper and you run your four inch
16:43
copper right up to the valve body
16:46
yes right up to the valve body and now
16:49
um your piping is protected at that
16:52
higher flow rate
16:53
right and we've seen it too that's
16:55
another thing that
16:56
that in some of those pictures it's you
16:59
see the two inch piping
17:01
and all of a sudden they come down with
17:02
a set of elbows and then they drop to
17:04
one inch
17:06
and when they go to one inch if there's
17:08
going to be a place of corrosion
17:09
erosion corrosion that's going to be it
17:11
right absolutely
17:13
you know and the thing is we're talking
17:14
copper when we're talking velocity but
17:17
all of the piping material you know will
17:20
operate at different velocities right
17:21
right yeah i know for example like pex
17:23
piping will only operate at
17:25
or they only recommend two feet per
17:27
second yeah
17:28
and then you'll see some assemblies done
17:30
in stainless and that's
17:32
quite a bit higher yeah stainless is
17:34
quite a bit higher velocity
17:36
well i think we covered this pretty well
17:39
yeah it's a pretty good overview of the
17:41
egomix electronic mixing valve all right
17:45
thank you for tuning in if you ever need
17:47
help
17:48
please feel free to contact our tech
17:50
support team anytime
17:51
at techsupport.us kaleppy.com
17:56
or call us during our business hours at
17:59
7:30 a.m to 4 30 p.m central time
18:04
at 414-238-2360
18:14
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