#5 Hydraulic Separators. Better than your Grandpa's closely-spaced tees?

Episode 5: Hydraulic separators not only simplify hydronic piping and save installation time, compared to closely spaced tees, they can also remove air and dirt to become a money-saving multi-purpose device. Get the whole story from Greg and Dan.

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Transcript

00:03

[Music]

00:06

welcome to

00:07

ask Caleffi the podcast that dives into

00:10

real life problems that plumbing and

00:12

hvac technicians face in the field

00:14

we're your hosts from the Caleffi tech

00:16

support team i'm greg tubbs

00:18

and i'm dan ferkus welcome we look

00:20

forward to sharing some stories from our

00:22

tech calls and using our background and

00:24

expertise to make your days a little

00:28

easier

00:31

hey welcome back to the ask Caleffi

00:33

podcast

00:34

this is episode five we're talking

00:36

hydraulic separators today

00:38

how we doing dan we're doing good yeah

00:40

hydraulic separators are a big topic we

00:42

get a lot of calls on those

00:43

we certainly do how to pipe them and

00:45

just the explanation of hydraulic

00:47

separation the concept of it right yep

00:50

so what is hydraulic separation let's

00:52

dive in right there

00:54

yeah i mean it's good place to start you

00:56

know hydraulic separation was

00:58

a concept that was brought in in the

01:00

early 50s by gil carlson from bng

01:02

yeah that's right uh way back when yeah

01:05

it was kind of the innovation of primary

01:07

secondary piping in boiler systems

01:09

you know where he realized or discovered

01:12

that putting close space tees in created

01:15

four connection points that were close

01:17

enough together that you could have a

01:18

pump on either side

01:20

and that pump either pump could come on

01:22

or off at any time without affecting the

01:24

other one

01:24

right so he essentially built a a

01:28

decoupling system

01:29

by sweating together closely space tees

01:32

to uh pumps to come on and off with

01:34

without conflict yeah

01:36

absolutely he could it was a way to

01:38

control flow on either side

01:40

without affecting the other you know

01:42

from there we

01:43

expanded and started adding buffer tanks

01:46

right yeah buffer tanks i mean it gives

01:49

a it gives a boiler

01:50

more room to to roam so to speak it

01:53

allows it to

01:54

have more capacity especially for added

01:57

volume to the system yup adding volume

01:59

to a system where there might be micro

02:00

zones

02:01

yeah especially when you had micro zones

02:03

that's where you saw the buffer tanks

02:05

being added because

02:06

by adding volume you know essentially

02:08

it's it's a big hydraulic separator

02:11

where you have the velocity instantly

02:14

drop

02:15

so you you don't have interference

02:17

between the micro zone and the boiler

02:19

you can maintain your

02:20

your design flow rate through your

02:21

boiler while having a micro zone

02:24

running at a smaller flow rate and one

02:26

doesn't affect the other

02:27

right and i think the hydraulic

02:30

separator

02:31

is always commonly the conception is

02:34

is kind of construed that you could use

02:37

it as

02:38

a buffer tank yeah i mean it's not

02:41

exactly a buffer tank

02:42

definitely a smaller volume a lot easier

02:44

to pipe

02:45

yeah i mean when you look at you know

02:46

mechanical rooms getting smaller and

02:49

you want to achieve you know hydraulic

02:51

separation

02:52

and you want to have more volume in your

02:55

system than closed space t's will

02:56

provide but you don't have that space

02:58

for a buffer tank or really need the

03:00

volume

03:01

of of a larger buffer tank a hydraulic

03:03

separator is a great solution right it's

03:06

that

03:06

i-beam shape it's it's pretty much it's

03:10

engineered it's ready to go

03:11

it takes up way less space you hang it

03:14

in your piping or on the wall and a

03:15

bracket

03:16

yeah and that i-beam shape that you

03:18

mentioned you know the body of that

03:20

is typically four times larger than the

03:22

pipe connection size

03:24

so that's where you get that instant

03:25

velocity drop

03:27

instant decoupling of the of the two

03:29

sides sure

03:30

the benefits of using a hydraulic

03:32

separator let's talk about that i mean

03:35

we both know it takes a ton of time to

03:40

cut pipe measure sweat things together

03:44

make sure it doesn't leak make sure

03:46

they're spaced properly sure there's

03:48

space

03:48

that's a big thing that is i mean and

03:51

you and i both been there we've worked

03:52

with guys that

03:54

close enough it'll work yeah and

03:57

somehow it does well it does i mean you

04:00

can you can

04:01

really pipe a system wrong and and it'll

04:04

work to some extent

04:05

but let's face it we want to get this

04:07

right yeah

04:08

get it right save time on the job less

04:11

chance of leakage

04:13

you know at a ton of solder joints right

04:15

so you

04:16

look at our hydraulic separator and all

04:18

of that is factored in so when you talk

04:20

about labor savings

04:21

you know you already have the body of

04:24

the

04:25

with four connection points two on the

04:27

left to on the right

04:28

yep you know and essentially you're

04:31

going to hook

04:32

your boiler or your source side to

04:35

to one side of the separator and your

04:37

system or load side to the other side it

04:39

doesn't matter what side it's on left or

04:41

right as long as

04:43

you're supply and return for your load

04:44

and your supply and return from your

04:46

source are on the same side of the body

04:48

right and then your hot ports are at the

04:50

top

04:51

and your cold ports are at the bottom

04:53

yeah that's kind of our general rule hot

04:55

on top gold on the bottom you got it

04:58

so we offer essentially two models

05:02

of hydraulic separator we have

05:05

the 548 which is just a standard

05:08

hydraulic separator it's sold on the

05:10

premise of

05:11

number one benefit hydraulic separation

05:15

and then yes it has an air vent on top

05:18

it has

05:18

a float type air vent on top

05:21

but that's really not going to remove

05:25

the air bubbles it's not going to remove

05:27

entrained air because

05:28

all we have is a diverter plate in the

05:30

flow path there we don't have a

05:32

coalescing mesh right yeah we talked

05:34

about air separators a couple weeks back

05:36

and you know you're right it doesn't

05:38

have the coalescing mesh so it's not a

05:40

separator

05:41

it does have the auto air vent we talked

05:42

about a few weeks back

05:45

where it'll let air out of the body of

05:47

the separator but it's not designed

05:49

there

05:49

to take the place of a system separator

05:52

right

05:52

right it's just taking whatever is in

05:54

that barrel

05:56

the larger bubbles and it's allowing

05:57

them to escape it does have a baffle a

06:00

stainless steel baffle in the middle

06:01

which helps with

06:03

your flow flow path and right in control

06:06

but it's not designed to remove

06:07

air right so you'll also have that drain

06:11

on the bottom

06:12

yes it does and you know another thing

06:15

we get asked too

06:16

is will this thing remove dirt there's

06:19

nothing

06:20

in there to divert any dirt out of flow

06:21

path no there isn't

06:23

but again when you look at the the

06:25

bigger body size and the velocity drop

06:28

because of the velocity drop of the

06:30

water you know dirt and particles will

06:32

have

06:33

you know a natural ability to gravity

06:36

yeah gravity to fall just like air will

06:39

have

06:40

the ability to rise so you know having

06:42

that air vent on top removes air from

06:45

the separator itself having the drain on

06:47

the bottom allows

06:48

you to purge off the separator and pull

06:50

any debris that might fall into the

06:52

bottom

06:53

definitely so it's still better than

06:56

your grandpa's closely spaced tees by

06:58

far

06:58

it sure is a big labor savings yep well

07:02

we've got that and then we have the 549.

07:07

so the 549 the sep 4 is our all-in-one

07:11

yeah it is that's the cadillac it is we

07:14

really

07:14

i like that product i do too i don't

07:16

know why that's not in every system

07:18

yeah and honestly i wish i would have

07:20

had something like that back when i was

07:22

installing because it just makes a ton

07:23

of sense

07:24

you know it's easy it is easy you don't

07:27

have to find space to fit in an air

07:29

separator

07:30

right well we should talk about it okay

07:32

all right you look at the the five four

07:34

nine five that's sep four

07:36

you know that's a four in one so that is

07:38

providing the hydraulic separation that

07:40

you

07:40

that we talked about with the 548 it's

07:43

going to provide

07:44

air removal but now has the coalescing

07:46

mesh in it so it is an air separator

07:48

yep so you know it's not just an air

07:51

vent

07:51

for this the body of hydraulic separator

07:54

it's actually a system air separator the

07:56

system air separator and then the added

07:58

bonus

07:59

is that coalescing mesh in the bottom

08:01

with the magnet

08:03

and the purge valve again to be able to

08:05

remove any

08:06

dirt and debris uh it'll catch ferrous

08:09

material

08:10

yeah so in a tight yep magnetite so if

08:12

you're running

08:13

dc pumps yeah variable speed pumps are

08:16

it's it's saving that rotor it's saving

08:19

those pumps

08:19

that that wet rotor is not catching

08:22

catching all that magnetite

08:23

out of out of the the fluid anymore

08:26

right the magnetite's going to end up

08:27

somewhere it's either going to get

08:28

pulled out by our separator or it's

08:30

going to end up in

08:32

in your variable speed drive yep or in

08:35

the low spot

08:35

of low points of your boiler heat

08:38

exchanger which

08:39

that's the other reason for using

08:40

something like this yeah protect your

08:42

boiler protect your pumps

08:43

yep well and then you look at you know

08:45

convenience

08:47

i mean you this this is an all-in-one

08:49

four-port connection

08:51

you pipe your your supply from your

08:52

boiler out into the top

08:54

of one side of the separator out of the

08:57

bottom back to your boiler with the

08:58

return

08:59

the load side you're coming out the top

09:02

out to your

09:02

load side supply on the one side of the

09:06

other side

09:07

and then return coming back into the

09:09

bottom on that same side

09:11

no air separator to locate no dirt or

09:14

magnetic separator locate it's all there

09:16

in four connections

09:17

right right it is what about using it in

09:21

chilled water applications you can still

09:23

use it in chilled water applications and

09:25

it's perfect for that

09:26

yeah the only catch is you're you're now

09:29

running your cold

09:30

supply water through the bottom so

09:34

hot on top of but now

09:37

in a chilled water application the cold

09:39

water is the supply out to the system so

09:41

you're going cold out through the bottom

09:44

and hot return

09:45

through the top back into the top yep

09:47

that will reverse application but

09:49

you know same concept so i think you

09:51

covered the piping pretty well

09:52

and just on how this system works but

09:55

what about sizing

09:56

sizing boy we get a lot of questions

09:58

about sizing

09:59

all the time and it's really pretty easy

10:03

if you understand what your system

10:05

requirements are

10:06

right let's be honest here i mean it's

10:08

always easy to look at and go

10:09

well it's two inch pipe i should have a

10:11

two inch separator

10:12

exactly yeah a lot of guys think you

10:14

know what we're gonna size it based on

10:16

pipe size and what you really need to

10:18

look at is what your flow requirements

10:20

are

10:20

for your system side and your load side

10:23

and that's probably easier in a new

10:26

construction or new build

10:28

scenario where you're designing this the

10:30

entire system

10:32

but when you get into retrofit

10:33

application maybe not so easy

10:35

no it's not and that's probably where we

10:38

get the most amount of questions about

10:40

sizing is

10:41

hey i got this old system uh it's got

10:44

all this old iron pipe in it you know so

10:47

there's a ton of

10:48

things to work weed through with that

10:50

right it's got a monster pump on it

10:52

yeah so okay we already know that this

10:55

building may or may not have gone

10:57

through

10:58

how many remodels updates of windows

11:00

added insulation all these

11:02

different factors right it was already

11:05

oversized to begin with

11:07

with probably pump the piping right

11:10

you know maybe even the boiler and now

11:12

they're stepping down to a pair of

11:13

smaller

11:15

modulating condensing boilers right

11:17

there's a lot going on with stuff like

11:19

that

11:19

so going back to what we were saying you

11:22

want to size it off your greatest flow

11:23

rate of the two

11:25

right so you'll look at your boilers and

11:27

essentially you know you'll come up with

11:29

a

11:29

design flow rate for your boiler or

11:32

multiple boilers depending on your

11:34

application but then you got to try to

11:36

do some engineering and figure out what

11:38

your

11:38

what your your load side is and come up

11:41

with a flow rate

11:42

there and then once you do that you're

11:44

going to pick the larger of the two flow

11:46

rates and you're going to size based on

11:47

that yeah

11:48

you have to size it correctly i mean you

11:50

definitely do not want to be

11:52

undersized no yes a hydraulic separator

11:56

is

11:57

a vessel where typically velocity drops

12:00

but if this thing is sized

12:02

too small you're going to create a

12:04

pressure drop

12:05

through that and that's going to create

12:07

a problem right exactly well and

12:09

and when you look at you know you talked

12:11

about sizing off pipe sizing

12:13

well that can really get you in trouble

12:15

because you know i'm going to use our

12:17

2-inch as a as a perfect

12:18

2-inch is the perfect example because

12:21

our 2-inch union body connection

12:24

is rated to 39 gpm right but you look at

12:27

our two inch

12:28

flanged that guy's good for 60 yep

12:32

60 gpm so that's where it's really

12:35

important to dive deep into your flow

12:38

rates and pick the

12:39

pick the proper flow rate yeah i mean

12:42

that's probably the one we get the most

12:43

questions about is the guy looks at and

12:45

sees the price difference

12:46

from a union model to a flange model and

12:49

then

12:50

that's kind of where they pump the

12:51

brakes and make the phone call well

12:54

you know i don't want to spend more

12:55

money than what i need to and rightfully

12:57

so because

12:58

that's what's going to get you your job

13:00

you come in there and

13:01

and quote the price you know say you

13:04

quote it wrong

13:04

and you're the cheaper of the two guys

13:06

and all of a sudden that system's not

13:08

working properly because you didn't

13:10

go through and figure out the sizing

13:12

correctly well you brought up a good

13:14

point

13:14

so you know you guys picking a two inch

13:17

model

13:17

because of cost well cost isn't

13:20

why pipe size or cost isn't why you pick

13:23

a product you pick it because it's the

13:25

right product for the applications so

13:27

exactly

13:27

you know you you may be able to pick

13:29

that two inch

13:30

union connection and save some cost when

13:33

really you needed the two inch flange

13:35

based on your flow rates

13:36

that's going to be your next problem job

13:38

so nobody wants that

13:40

no and then it ended up costing you the

13:42

contractor the money

13:44

yeah because eventually you'll have to

13:45

come back and put the right product

13:47

in to get the right performance out of

13:49

your system and that's when re-piping

13:52

because

13:52

you know face it the dimensions on a

13:55

two-inch union connection versus a

13:57

two-inch flange

13:58

is greatly different yes it is

14:01

yeah and if you don't have if you don't

14:03

have an idea i mean give us a call and

14:05

we'll help

14:05

talk you through it yeah that's what

14:07

we're here for we'd rather

14:09

have you guys make the right choice in

14:11

product versus just

14:12

winging it and going out there and

14:14

looking foolish later right

14:16

absolutely so now that we beat that one

14:18

in in the

14:19

head here pretty hard the other question

14:21

we get is on installation a guy goes in

14:24

puts this thing in and he looks at it

14:25

and says you know that

14:27

bottom ball valve looks like a perfect

14:29

spot to pipe in the fill

14:31

and an expansion tank right yeah what do

14:34

we say to that

14:35

definitely not no no definitely not and

14:38

we have guys that'll question you know

14:40

why not well

14:42

let's think about this if there is a if

14:44

this is an old system with old iron

14:45

piping and you didn't go through and do

14:47

a flush on it where's all that heavy

14:49

deposit and debris coming from and going

14:51

too

14:51

right in the bottom of that separator

14:53

that's right even if it doesn't have a

14:55

coalescing mesh in it it's still going

14:57

to be a sediment trap right

14:59

yep easy enough to just you know pipe

15:01

that in on the return side on either

15:02

side of that separator

15:04

right put it in the return on the

15:05

primary or secondary side as long as you

15:07

don't

15:07

have a pump pumping directly at that

15:10

expansion tank and fill you're in good

15:12

shape yeah it's a good spot for it yeah

15:14

don't tie it into the bottom you'll be

15:15

in trouble

15:16

right so the other question we get

15:20

is just when you go to service it you

15:23

know when you go to do a blow off on it

15:25

for the first time like

15:26

on a sep 4. what is the protocol for

15:29

that

15:30

you mean like how often do we do that

15:32

right

15:33

that's the question i get well how often

15:35

do i how often do i flush it how often

15:37

do i

15:37

always get that question and this i

15:40

can't give you an answer on how often

15:42

but

15:42

but my general comment to that is

15:46

it really depends on your system if

15:48

you're working with an old system

15:50

and old iron pipe and radiators and it's

15:52

a dirty system

15:54

you might be flushing it once a week you

15:55

might be flushing it once a day for the

15:57

first week

15:58

right i mean that's probably that's the

16:00

best answer we can give you because we

16:02

don't know what your water quality is

16:03

like or the system

16:05

if it's nasty old like you said old iron

16:08

pipe

16:08

right and you didn't do a major pressure

16:12

cleaning on it if you don't do a pump it

16:14

out and dump it and high pressure clean

16:16

it it's

16:17

probably going to be pretty darn dirty

16:18

and now that separator is going to act

16:20

as a kind of a filter

16:22

yeah it is well and i i usually say that

16:25

you know what start out you know if

16:27

you're on site once you get it

16:28

operational flush it once a day

16:31

you know you're going to see what comes

16:32

out of it you're going to flush it until

16:34

it runs clean

16:35

for 10 to 15 seconds of clean water

16:38

coming out and

16:39

then consider it flushed sure you know

16:42

then maybe set up a time to come back a

16:43

month later or six months later and i

16:46

think

16:46

eventually you want to get the system to

16:48

a point where when you're in doing your

16:51

your annual maintenance you're doing a

16:53

flush on

16:54

the hydraulic separator and cleaning

16:56

that sure obviously when you go to

16:58

service one of these you do a blow down

17:00

you know if you've got a sep 4 or even a

17:02

548 but we'll use the sep 4 as an

17:04

example because there might be a couple

17:05

more steps in there but no matter what

17:07

when you're doing a blow down

17:08

pumps got to be shut off system can't be

17:10

running then you're either going to go

17:12

with a bucket or a garden hose into a

17:14

bucket or a floor drain

17:15

i'd prefer to see a bucket just because

17:17

you don't want to see all that nasty

17:18

debris going down somebody's floor drain

17:20

right plugging it up

17:21

so purge off into a bucket after you

17:24

shut the pumps off

17:25

yeah make sure it's pumps on both sides

17:27

yup you want to make sure that all your

17:29

pumps are shut down yep and just

17:32

open that you pull the magnet if you got

17:34

one with a magnet

17:35

uh the larger ones have a bayonet in the

17:37

bottom you just unscrew that bayonet and

17:39

drop the bayonet out of it

17:40

right and then uh or if it's a smaller

17:42

union type they've got that magnetic

17:44

band

17:45

you pull that you open the ball valve on

17:47

the bottom purge it off into a bucket

17:49

until you see clean water

17:50

close it back up system should auto fill

17:53

if you got an auto fill on it so it's

17:54

taken care of that already

17:56

right then you can restore back into

17:57

operation after you put the magnets in

17:59

place

18:00

right yeah i mean pretty pretty simple

18:02

as far as maintenance goes

18:04

yeah well anything else we should cover

18:05

with hydraulic separators you know i

18:08

it's funny as you mentioned it you know

18:09

i think we did a good job of covering

18:12

what they are how they work how to

18:13

install and maintenance them

18:15

as you know question comes to mind that

18:17

i get all the time on tech calls

18:20

you know we talked about not having a

18:21

pressure drop across them you know

18:23

we get engineers that call and they want

18:25

to know what the pressure drop is

18:27

how do i calculate that there is a

18:29

calculation on that

18:30

it's a tough one to try and do if you

18:32

don't like doing algebra and me

18:34

i'm not a big algebra guy right yeah

18:37

there's a formula on our ass cluffy that

18:39

you can pull up if you want to know how

18:41

to calculate the

18:42

the pressure drop across the hydraulic

18:44

separator and it's possible but

18:47

but i think that you know it you

18:49

calculate it once you calculate it twice

18:51

you're going to realize that it's

18:52

it's so minimal it's not even worth

18:55

putting into your

18:56

system and noteworthy is uh hydronics

18:58

number 15 on separation if you guys

19:01

want a little more information on on

19:03

separators go check out idronics15 i

19:06

mean you can pull it right up on our

19:07

website

19:08

as a pdf you can read it whenever you

19:10

want i think we even have them available

19:12

online as well like you could you can

19:14

download it or you can go in

19:16

and and i think order a copy but you can

19:19

you can download the digital copy right

19:21

online

19:21

yeah it's pretty handy there's a lot of

19:23

great concept drawings

19:25

in hydronics 50. there is and it's not

19:27

only hydraulic separation it's

19:29

separation in general so it's going to

19:30

talk about dirt separation that we

19:32

talked about last week and the air

19:34

separation we talked about the week

19:35

before so it's going to kind of cover

19:37

all those topics in that one

19:38

issue sure well i think that's it so

19:41

greg what do you want to talk about next

19:43

week

19:43

well dan i think we're going to talk

19:44

about balancing valves well that's a

19:46

great topic we get a ton of questions on

19:48

those

19:48

we certainly do well we'll see you next

19:50

week yep tune in next week

19:54

thank you for tuning in if you ever need

19:56

help please feel free to contact our

19:58

tech support team

19:59

anytime at techsupport.us

20:03

Caleffi.com or call us during our

20:06

business hours

20:07

at 7 30 a.m to 4 30 p.m

20:11

central time at 414-238-2360

20:22

[Music]

20:28

you