Clark Solutions
120 Series, Pressure, Vacuum, Diff. Pressure & Temp. Switches
Explosion Proof, Adjustable Ranges 30" Vac to 6000 PSI,
-180°F to 650°F

(Page 4 of 9)
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MODEL H121, SINGLE SWITCH WITH EXTERNAL ADJUSTMENT VIA REFERENCE DIAL, 1 CONDUIT
MODEL H122, DUAL SWITCH WITH EXTERNAL ADJUSTMENT VIA REFERENCE DIAL, 1 CONDUIT
MODEL H122P, TWO HERMETICALLY SEALED SINGLE SWITCHES, EXTERNAL REFERENCE DIAL ADJUSTMENT,
1 CONDUIT
Range/Material Code Adjustable Set Point Range Deadband **Proof Pressure Dial Divisions

psi

bar

psi

bar

psi

bar

psi

Phosphor bronze bellows with 1/4" NPT (female) nickel-plated brass pressure connection

270

0 to 200

0 to 13.8

1.5 to 8

0.1 to 0.6

250

17.2

5

274

0 to 300

0 to 20.7

2 to 10

0.1 to 0.7

350

24.1

10

Buna-N diaphragm and O-Ring with 1/4" NPT (female) aluminum pressure connection and cap

450

30" Hg Vac to 0

-1 to 0 mbar

0.1 to 0.4"wc

0.003 to 0.01

225

15.5

0.5" Hg

452

30" Hg Vac to 20 psi

-1 to 1.4 mbar

0.1 to 1" Hg

0.003 to 0.03

225

15.5

1" & 0.5 psi

453

0 to 20

0 to 1.4 mbar

0.05 to 0.2

0 to 0.01

225

15.5

0.5

454

0 to 30

0 to 2.1 mbar

0.05 to 0.3

0 to 0.02

225

15.5

0.5

Teflon® diaphragm and O-Ring with 1/4" NPT (female) 316L stainless steel pressure connection and cap

550

30" Hg Vac to 0

-1 to 0

0.1 to 0.6" Hg

0.003 to 0.02

225

15.5

0.5" Hg

552

30" Hg Vac to 20 psi

-1 to 1.4

0.2 to 1" Hg

0.007 to 0.03

225

15.5

1" & 0.5 psi

553

0 to 20

0 to 1.4

0.05 to 0.3

0 to 0.02

225

15.5

0.5

554

0 to 30

0 to 2.1

0.1 to 0.4

0.01 to 0.03

225

15.5

0.5

555

0 to 100

0 to 6.9

0.25 to 0.75

0.02 to 0.05

225

15.5

2

Buna-N diaphragm and O-Ring with 1/4" NPT (female) nickel-plated brass pressure connection; Optional Viton® diaphragm & O-Ring available for code 701 & 703

701

3 to 30

0.2 to 2.1

1 to 3

0.07 to 0.2

1000

68.9

0.5

702

10 to 100

0.7 to 6.9

1 to 5

0.07 to 0.3

1000

68.9

2

703

30 to 300

2.1 to 20.7

2 to 7

0.14 to 0.5

1000

68.9

10

704

50 to 500

3.4 to 34.5

3 to 12

0.2 to 0.8

2500

172.4

10

705

200 to 1000

13.8 to 68.9

5 to 25

0.3 to 1.7

2500

172.4

25

** Proof Pressure: The maximum pressure to which a pressure sensor may be occasionally subjected, which causes no permanent damage. Unit may require calibration.

DIFFERENTIAL PRESSURE MODEL J120K SINGLE SWITCH WITH INTERNAL ADJUSTMENT, DUAL CONDUIT
Range/Material Code Adjustable Set Point Range High end of range on rise, low end on fall Deadband ***Working Pressure **Proof Pressure

"wcd/psid

mbar/bar

"wc/psi

mbar/bar

psi

bar

psi

bar

Welded 316L bellows with 1/2" NPT (female) pressure connections

S147B

3 to 30 psid

0.2 TO 2.1 bar

0.3 TO 1.5 psi

0.02 to 0.1bar

30" Hg Vac to 100

-1 to 6.9

300

20.7

S157B

10 to 100 psid

0.7 TO 6.9 bar

0.5 TO 2 psi

0.03 to 0.14 bar

30" Hg Vac to 180

-1 to 12.4

300

20.7

Brass bellows with 1/4" NPT (female) nickel-plated brass pressure connections

147

3 to 30 psid

0.2 to 2.1 bar

0.3 to 1.5 psi

0.02 to 0.1bar

30" Hg Vac to 100

-1 to 6.9

180

12.4

157

10 to 100 psid

0.7 to 6.9 bar

0.5 to 2 psi

0.03 to 0.14 bar

30" Hg Vac to 150

-1 to 10.3

180

12.4

316L stainless steel bellows and 1/4" NPT (female) pressure connections

367

10 to 100 psid

0.7 to 6.9

4 to 10

0.3 to 0.7

0 to 350

0 to 24.1

500

34.5

Buna-N diaphragm and O-Ring with stainless steel 1/4" NPT (female) pressure connections

36

3 to 30 psid

0.2 to 2.1

1 to 5

0.07 to 0.3

0 to 350

0 to 24.1

1000

68.9

37

10 to 100 psid

0.7 to 6.9

2 to 8

0.1 to 0.6

0 to 500

0 to 34.5

1000

68.9

38

30 to 300 psid

2.1 to 20.7

2 to 15

0.1 to 1.0

0 to 1000

0 to 68.9

2500

172.4

39

50 to 500 psid

3.4 to 34.5

3 to 20

0.2 to 1.4

0 to 1000

0 to 68.9

2500

172.4

Buna-N diaphragm and O-Ring with 1/4" NPT (female) aluminum pressure connections

455

5 to 80 "wcd

12.4 to 200 mbar

1 to 4"wcd

2 to 10 mbar

30" Hg Vac to 225

-1 to 15.5

225

15.5

456

2 to 20 psid

0.1 to 1.4 bar

0.1 to 0.3 psi

6.9 to 20.7 mbar

30" Hg Vac to 225

-1 to 15.5

225

15.5

457

3 to 30 psid

0.2 to 2.1 bar

0.1 to 0.4 psi

6.9 to 27.6 mbar

30" Hg Vac to 225

-1 to 15.5

225

15.5

Kapton® diaphragm, Buna-N sealing diaphragms and epoxy coated aluminum 1/8" NPT (female) pressure connections

540

0.2 to 7"wcd

0.5 to 17.4 mbar

0.05 to 0.4"wc

0.1 to 0.1 mbar

200

13.8

400

27.6

541

1 to 20"wcd

2.5 to 49.7 mbar

0.1 to 0.7"wc

0.2 to 1.7 mbar

200

13.8

400

27.6

542

5 to 50"wcd

12.4 to 124.4 mbar

0.2 to 2.0"wc

0.5 to 5.0 mbar

200

13.8

400

27.6

543

10 to 200"wcd

24.9 to 497 mbar

0.5 to 6.0"wc

1.2 to 14.9 mbar

200

13.8

400

27.6

544

2 to 20 psid

0.1 to 1.4 bar

0.1 to 0.8 psi

6.9 to 55.2 mbar

1200

82.7

2500

172.4

545

5 to 50 psid

0.3 to 3.4 bar

0.2 to 1.6 psi

0 to 0.1 bar

1200

82.7

2500

172.4

546

0 to 125 psid

0.7 to 8.6 bar

0.4 to 3.5 psi

0 to 0.2 bar

1200

82.7

2500

172.4

547

50 to 250 psid

3.4 to 17.2 bar

1.5 to 7.2 psi

0.1 to 0.5 bar

1200

82.7

2500

172.4

548

100 to 500 psid

6.9 to 34.5 bar

2.0 to 12.0 psi

0.1 to 0.8 bar

1200

82.7

2500

172.4

Teflon® and Buna-N diaphragms, Buna-N O-Ring with 1/4" (female) aluminum pressure connections

559

10 to 100 psid

0.7 to 6.9 bar

0.2 to 1 psi

14 to 69 mbar

30" Hg Vac to 225

-1 to 15.5

225

15.5

** Proof Pressure: The maximum pressure to which a pressure sensor may be occasionally subjected, which causes no permanent damage. Unit may require calibration.

***Working Pressure Range: The pressure range within which two opposing sensors can be safely operated and still maintain set point adjustability provided the difference in pressure between them does not exceed the designated adjustable range.

DIFFERENTIAL PRESSURE MODEL H121K SINGLE SWITCH WITH EXTERNAL
ADJUSTMENT VIA REFERENCE DIAL
DIFFERENTIAL PRESSURE MODEL H122K DUAL SWITCH WITH EXTERNAL
ADJUSTMENT VIA REFERENCE DIAL
Range/Material Code Adjustable Set Point Range High end of range on rise, low end on fall Deadband ***Working Pressure **Proof Pressure

"wcd/psid

mbar/bar

"wcd/psi

mbar/bar psi bar psi bar

Welded 316L bellows with 1/2" NPT (female) pressure connections

S147B

3 TO 30 psid

0.2 TO 2.1 bar

0.3 TO 2 psi

20 to 140 mbar

30" Hg Vac to 100

-1 to 6.9

300

20.7

S157B

10 TO 100 psid

0.7 TO 6.9 bar

0.5 TO 3 psi

30 to 200 mbar

30" Hg Vac to 180

-1 to 12.4

300

20.7

Brass bellows with 1/4" NPT (female) nickel-plated brass pressure connections

147

3 to 30 psid

0.2 to 2.1 bar

0.3 TO 2 psi

20 to 140 mbar

30" Hg Vac to 100

-1 to 6.9

180

12.4

157

10 to 100 psid

0.7 to 6.9 bar

0.5 TO 3 psi

30 to 200 mbar

30" Hg Vac to 150

-1 to 10.3

180

12.4

Buna-N diaphragm and O-Ring with 1/4" NPT (female) aluminum pressure connections

456

2 to 20 psid

0.1 to 1.4 bar

0.1 to 0.3 psi

0.01 to 0.02

30" Hg Vac to 225

-1 to 15.5

225

15.5

457

3 to 30 psid

0.2 to 2.1 bar

0.1 to 0.4 psi

0.01 to 0.03

30" Hg Vac to 225

-1 to 15.5

225

15.5

Teflon® and Buna-N diaphragms, Buna-N O-Ring with 1/4" (female) aluminum pressure connections

559

10 to 100 psid

0.7 to 6.9 bar

0.2 to 1 psi

0.01 to 0.07

30" Hg Vac to 225

-1 to 15.5

225

15.5

*Over Range Pressure: The maximum pressure that may be applied continuously without causing damage and maintaining set point repeatability
** Proof Pressure: The maximum pressure to which a pressure sensor may be occasionally subjected, which causes no permanent damage. Unit may require calibration.
***Working Pressure Range: The pressure range within which two opposing sensors can be safely operated and still maintain set point adjustability provided the difference in pressure between them does not exceed the designated adjustable range.

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