Omega Engineering PSW490B, User Manual, Page: 5 / 8

DIFFERENTIAL PRESSURE SWITCH –
INCHES OF WATER
DIFFERENTIAL PRESSURE SWITCH – PSID
A
Ø 0.28
(3 Holes)
D
C
G
E
B
H
3/4 NPT
1/4 NPT
Female
1/4 NPT
Female
A
Ø 0.28
(3 Holes)
C
1/4 NPT
High
Pressure
Inlet
1/4 NPT
Low Pressure
Inlet
B
D
E
F
H
G
3/4 NPT
C
A
U
T
IO
N
TO
PR
EV
EN
T IGNITION OF
H
A
Z
A
R
D
O
U
S
AT
MO
SPH
ERE TURN
OF
F
P
O
W
E
R
B
E
FO
RE
OPENING. CLO
SE
T
IG
H
T
LY
BE
FO
RE OPERAT
IN
G
.
C
A
U
T
IO
N
C
O
UP
ER
LE
CO UR AN
TA
VA
N
T
D
’O
U
V
R
IR
.
B
IE
N
FE
RM
ER
AV
AN
T
DE
M
E
T
T
R
E
E
N
SE
RV
IC
E.
C
D
E
F
H
I
0.28 THRU
(3 PLACES)
1/4 NPT
FEMALE
3/4 NPT
(2 PLACES)
B
A
1/4 NPT
FEMALE
®
C
A
U
T
IO
N
TO
PR
EV
EN
T IGNITION OF
H
A
Z
A
R
D
O
U
S
AT
MO
SPH
ERE TURN
OF
F
P
O
W
E
R
B
E
FO
RE
OPENING. CLO
SE
T
IG
H
T
LY
BE
FO
RE OPERAT
IN
G
.
C
A
U
T
IO
N
C
O
UP
ER
LE
CO UR
AN
TA
VA
N
T
D
’O
U
V
R
IR
.
B
IE
N
FE
RM
ER AV
AN
T
DE
M
E
T
T
R
E
E
N
SE
RV
IC
E.
B
A
C
H
D
E
F
G
0.28 THRU
(3 PLACES)
3/4 NPT
(2 PLACES)
1/4 NPT
LOW PRESSURE
INLET
1/4 NPT HIGH
PRESSURE
INLET
®
DSW490B
DSW490B
PSW790B
PSW790B
DIMENSIONS (Inches) – PSID Ranges
STYLE A B C D E F G H
DSW490B 4.0 3.25 3.31 2.75 2.31 1.19 2.31 2.27
DSW790B 7.78 5.20 4.38 3.88 3.58 1.22 2.31 .312
DIMENSIONS (Inches) – ˝H
2
O Differential Ranges
STYLE A B C D E F G H I
DSW490B 5.69 4.0 3.25 3.31 5.13 – 1.43 2.75 –
DSW790B 6.38 5.20 4.38 3.88 3.96 1.22 – .312 5.13