pressure drop charts - mrpex systems · pressure drop charts ... divide the pipe length by 10, ......

7
PRESSURE DROP CHARTS 1-800-716-3406 87 PRESSURE DROP FOR SMALL PEX TUBING AT 100 F Take the total heat load (BTUH) for the area that the loop is covering and divide it by 501. Divide the result with the Delta-T to find GPM for the loop. Find the closest flow for the loop in the left GPM column of the chart. Move to the right to the correct pipe size intersecting line. Move down to read to read the pressure drop per 10 feet of pipe. Divide the loop length by 10, then multiply the result with the given pressure drop for 10 feet to get the total pressure drop for the loop. NOTE: This chart is for 100% water, and only includes the pressure drop for the PEX pipe itself. You need to add the drop for other equipment. For the manifold, add about 2 ft/hd. If glycol is used, use the correction charts on pages 92–93. PRESSURE DROP CHARTS

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Page 1: PRESSURE DROP CHARTS - MrPEX Systems · PRESSURE DROP CHARTS ... Divide the pipe length by 10, ... value of the component and then use formula below to establish the head loss (ft/hd)

PR

ESS

UR

E D

RO

P C

HA

RTS

1-800-716-3406 87

PR

ESS

UR

E D

RO

P F

OR

SM

ALL

PEX

TU

BIN

G A

T 10

0 F

›Ta

ke t

he t

otal

hea

t lo

ad (B

TUH

) for

the

are

a th

at t

he lo

op is

cov

erin

g an

d di

vide

it b

y 50

1. ›D

ivid

e th

e re

sult

with

the

Del

ta-T

to

find

GPM

for

the

loop

. ›Fi

nd t

he c

lose

st fl

ow f

or t

he lo

op in

the

left

GPM

col

umn

of t

he c

hart

. ›M

ove

to t

he ri

ght

to t

he c

orre

ct p

ipe

size

inte

rsec

ting

line.

›M

ove

dow

n to

read

to

read

the

pre

ssur

e dr

op p

er 1

0 fe

et o

f pi

pe.

›D

ivid

e th

e lo

op le

ngth

by

10, t

hen

mul

tiply

the

resu

lt w

ith t

he g

iven

pre

ssur

e dr

op f

or 1

0 fe

et t

o ge

t th

e to

tal p

ress

ure

drop

for

the

loop

.

NO

TE: T

his

char

t is

for

100

% w

ater

, and

onl

y in

clud

es t

he p

ress

ure

drop

for

the

PEX

pip

e its

elf.

You

need

to

add

the

drop

for

oth

er e

quip

men

t. Fo

r the

man

ifold

, ad

d ab

out

2 ft

/hd.

If g

lyco

l is

used

, use

the

cor

rect

ion

char

ts o

n pa

ges

92–9

3.

PRESSURE DROP CHARTS

Page 2: PRESSURE DROP CHARTS - MrPEX Systems · PRESSURE DROP CHARTS ... Divide the pipe length by 10, ... value of the component and then use formula below to establish the head loss (ft/hd)

PR

ESS

UR

E DR

OP C

HA

RTS

MRPEXSYSTEMS.COM88

PR

ESS

UR

E D

RO

P F

OR

LA

RG

E P

EX T

UB

ING

AT

100

F

›Fi

nd t

he c

lose

st fl

ow f

or t

he lo

op in

the

left

GPM

col

umn

of t

he c

hart

. ›St

ep 2

, Mov

e to

the

righ

t to

the

cor

rect

pip

e si

ze in

ters

ectin

g lin

e. ›St

ep 3

, Mov

e do

wn

to re

ad t

o re

ad t

he p

ress

ure

drop

per

10

feet

of

pipe

. ›St

ep 4

, Div

ide

the

pipe

leng

th b

y 10

, the

n m

ultip

ly t

he re

sult

with

the

giv

en p

ress

ure

drop

for

10

feet

to

get

the

tota

l pre

ssur

e dr

op f

or t

he p

ipe

leng

th.

NO

TE: T

his

char

t is

for

100

% w

ater

, and

onl

y in

clud

es t

he p

ress

ure

drop

for

the

PEX

pip

e its

elf.

You

need

to

add

the

drop

for

oth

er e

quip

men

t. If

glyc

ol is

use

d, u

se t

he

corr

ectio

n ch

arts

on

page

s 92

–93.

Page 3: PRESSURE DROP CHARTS - MrPEX Systems · PRESSURE DROP CHARTS ... Divide the pipe length by 10, ... value of the component and then use formula below to establish the head loss (ft/hd)

PR

ESS

UR

E D

RO

P C

HA

RTS

1-800-716-3406 89

PR

ESS

UR

E D

RO

P F

OR

PA

P T

UB

ING

AT

100

F

›Ta

ke t

he t

otal

hea

t lo

ad (B

TUH

) for

the

are

a th

at t

he lo

op is

cov

erin

g an

d di

vide

it b

y 50

1. ›St

ep 2

, Div

ide

the

resu

lt w

ith t

he D

elta

-T t

o fin

d G

PM f

or t

he lo

op.

›St

ep 3

, Fin

d th

e cl

oses

t flo

w f

or t

he lo

op in

the

left

GPM

col

umn

of t

he c

hart

. ›St

ep 4

, Mov

e to

the

righ

t to

the

cor

rect

pip

e si

ze in

ters

ectin

g lin

e. ›St

ep 5

, Mov

e do

wn

to re

ad t

o re

ad t

he p

ress

ure

drop

per

10

feet

of

pipe

. ›St

ep 5

, Div

ide

the

loop

leng

th b

y 10

, the

n m

ultip

ly t

he re

sult

with

the

giv

en p

ress

ure

drop

for

10

feet

to

get

the

tota

l pre

ssur

e dr

op f

or t

he lo

op.

NO

TE: T

his

char

t is

for

100

% w

ater

, and

onl

y in

clud

es t

he p

ress

ure

drop

for

the

PAP

pip

e its

elf.

You

need

to

add

the

drop

for

oth

er e

quip

men

t. Fo

r the

man

ifold

, add

abo

ut 2

ft/

hd. I

f gl

ycol

is u

sed,

use

the

cor

rect

ion

char

ts o

n pa

ges

92–9

3.

Page 4: PRESSURE DROP CHARTS - MrPEX Systems · PRESSURE DROP CHARTS ... Divide the pipe length by 10, ... value of the component and then use formula below to establish the head loss (ft/hd)

PR

ESS

UR

E DR

OP C

HA

RTS

MRPEXSYSTEMS.COM90

PR

ESS

UR

E D

RO

P F

OR

CO

PP

ER T

UB

ING

AT

100

F

›Fi

nd t

he c

lose

st fl

ow f

or t

he lo

op in

the

left

GPM

col

umn

of t

he c

hart

. ›St

ep 2

, Mov

e to

the

righ

t to

the

cor

rect

pip

e si

ze in

ters

ectin

g lin

e. ›St

ep 3

, Mov

e do

wn

to re

ad t

o re

ad t

he p

ress

ure

drop

per

10

feet

of

pipe

. ›St

ep 4

, Div

ide

the

pipe

leng

th b

y 10

, the

n m

ultip

ly t

he re

sult

with

the

giv

en p

ress

ure

drop

for

10

feet

to

get

the

tota

l pre

ssur

e dr

op f

or t

he p

ipe

leng

th.

NO

TE: T

his

char

t is

for

100

% w

ater

, and

onl

y in

clud

es t

he p

ress

ure

drop

for

the

cop

per p

ipe

itsel

f. Yo

u ne

ed t

o ad

d th

e dr

op f

or o

ther

equ

ipm

ent.

If gl

ycol

is u

sed,

use

the

co

rrec

tion

char

ts o

n pa

ges

92–9

3.

Page 5: PRESSURE DROP CHARTS - MrPEX Systems · PRESSURE DROP CHARTS ... Divide the pipe length by 10, ... value of the component and then use formula below to establish the head loss (ft/hd)

PR

ESS

UR

E D

RO

P C

HA

RTS

1-800-716-3406 91

CV V

ALU

ESTh

e pr

essu

re d

rop

for h

ydro

nic

heat

ing

com

pone

nts

are

norm

ally

des

crib

ed b

y th

eir C

v val

ue. T

he C

v val

ue d

escr

ibes

at

wha

t flo

w (i

n gp

m) t

he p

ress

ure

drop

ove

r the

co

mpo

nent

will

be 1

psi

(equ

al t

o 2.

31 f

t/hd

). Ch

eck

with

the

man

ufac

ture

r for

the

Cv v

alue

of

the

com

pone

nt a

nd t

hen

use

form

ula

belo

w t

o es

tabl

ish

the

head

loss

(ft/

hd).

HEA

D L

OSS

(FT.

HD

.) O

VER

VALV

ES E

TC.:

(1.5

2 x

GPM

/ Cv

)2 (G

PM is

the

flow

, and

Cv

is t

he v

alve

par

amet

er)

(Mul

tiply

the

flow

by

1.52

and

then

div

ide

by t

he C

v va

lue.

Mul

tiply

the

resu

lt by

itse

lf)

Page 6: PRESSURE DROP CHARTS - MrPEX Systems · PRESSURE DROP CHARTS ... Divide the pipe length by 10, ... value of the component and then use formula below to establish the head loss (ft/hd)

PR

ESS

UR

E DR

OP C

HA

RTS

MRPEXSYSTEMS.COM92

PR

ESS

UR

E H

EAD

CO

RR

ECTI

ON

FA

CTO

R F

OR

TEM

PER

ATU

RES

AN

D P

RO

PY

LEN

E G

LYC

OL

Pres

sure

hea

d co

rrec

tion

fact

or (m

ultip

lier)

as a

fun

ctio

n of

ave

rage

flui

d te

mpe

ratu

re (°

F) a

nd p

ropy

lene

gly

col c

once

ntra

tion

(Vol

ume

%).

Usi

ng t

he C

hart

: ›Fi

nd t

he a

vera

ge w

ater

tem

pera

ture

to

the

left

›M

ove

horiz

onta

lly t

o th

e rig

ht u

ntil

the

inte

rsec

tion

with

act

ual g

lyco

l con

cent

ratio

n ›G

o do

wn

vert

ical

ly a

nd re

ad t

he fl

ow c

orre

ctio

n fa

ctor

›M

ultip

ly t

he h

ead

loss

(ft/

hd) w

ith t

he c

orre

ctio

n fa

ctor

for

cor

rect

resu

lt

Page 7: PRESSURE DROP CHARTS - MrPEX Systems · PRESSURE DROP CHARTS ... Divide the pipe length by 10, ... value of the component and then use formula below to establish the head loss (ft/hd)

PR

ESS

UR

E D

RO

P C

HA

RTS

1-800-716-3406 93

FLO

W C

OR

REC

TIO

N F

AC

TOR

FO

R T

EMP

ERAT

UR

ES A

ND

PR

OP

YLE

NE

GLY

CO

LFl

ow c

orre

ctio

n fa

ctor

(mul

tiplie

r) as

a f

unct

ion

of a

vera

ge fl

uid

tem

pera

ture

(°F)

and

pro

pyle

ne g

lyco

l con

cent

ratio

n (V

olum

e %

).

Usi

ng t

he C

hart

: ›Fi

nd t

he a

vera

ge w

ater

tem

pera

ture

to

the

left

›M

ove

horiz

onta

lly t

o th

e rig

ht u

ntil

the

inte

rsec

tion

with

act

ual g

lyco

l con

cent

ratio

n ›G

o do

wn

vert

ical

ly a

nd re

ad t

he fl

ow c

orre

ctio

n fa

ctor

›M

ultip

ly t

he fl

ow (G

PM) w

ith t

he c

orre

ctio

n fa

ctor

for

cor

rect

resu

lt