NBC-Series - ABB Semiconductors

Specification sheet

Model NBC

Absolute pressure

transmitter

Deltapi N Series

Pneumatic Transmitters

The blind type absolute pressure transmitter, mod. NBC, is

used to measure an absolute pressure and convert it into a

proportional pneumatic signal.

The instrument works on the force-balance principle and

consists of two main units:

the measuring unit detects the absolute-pressure variation

and consists of two forged bodies and a measuring capsule.

A diaphragm capsule is placed within two halfbodies to releve

the absolute pressure applied to the positive chamber.

The capsule is available in two versions: 2in or 3in diameter

diaphragms inside of which is obtained the vacuum. The

structure of the diaphragm capsule can withstand the

maximum overrange without damage.

the transmission unit converts the force applied to the

measuring element into a proportional output pneumatic

signal.

The output pressure, generated by a flapper nozzle relay, is fed

to a feedback bellows with a rising pressure until the bellows

force balances that of the measuring element.

Span value continuously adjustable by an internal micrometric

screw.

Zero value adjustable by an external screw.

Mounting in a vertical position on 2in diameter pipe by a

special bracket.

OPTIONAL EXTRA FEATURES

Special feedback bellows allow to reduce the standard

calibration span to a lower value (see table)

A zero suppression device allows to set as a zero of the

transmitter a measured variable value different from the

absolute zero.

The sum of the zero suppression value (S) plus the calibrated

span cannot exceed the upper range limit (M) suitable for the

diaphragm capsule : S + span ≤ M (see table).

GENERAL CHARACTERISTICS

Air filter regulator can be directly mounted on the transmitter,

with or without pressure gauge, and connected with piping and

fittings either in stainless steel or copper.

Special versions of air filter regulator and gauges, in stainless

steel, are available on request.

Oxygen measurements, special degreasing and final test

operations can be required on the oxygen measuring

transmitter.

Cover material

thermoplastic resin

Diaphragm material

AISI 316L, Monel (*), Hastelloy C (*)

(*) Maximum overrange pressure reduced to 1MPa (10 bar)

Gaskets material

PTFE, Viton

Surface protections

- carbon steel body and flange: zinc plating and chrome

passivation

- AISI 316L body and flange: no protection

Process connections (see figure ref. D)

- on flange: 1/2 in NPT-F

- on adapter: 1/4 in NPT-F

- center distance: 54 mm.

Pneumatic connections

- Air supply (in figure ref. A): 1/4 in NPT-F

- Output (in figure ref. B): 1/4 in NPT-F

Pressure gauge

Brass with stainless steel case (all stainless steel on request)

external diameter 51 mm; 0-200 kPa, 0-2 bar and 0-30 psi

indication on 82 mm/260° scale.

Air filter regulator

with copper or stainless steel piping, as specified.

Die cast aluminium alloy with light grey epoxy finish.

Net weight (maximum)

10 kg approx

Packing

expanded polythene box

Air supply

nom. 140 kPa (1.4 bar, 20 psi); min. 125 kPa (1.25 bar,

18 psi); max. 175 kPa (1.75 bar, 25 psi)

Output signal

20 to 100 kPa/0.2 to 1 bar, 3 to 15 psi or 0.2 to 1 kg/cm2

Static air consumption

350 Nl/h

Maximum output flow

- with rising output pressure: 30 Nl/min.

- with falling output pressure: 40 Nl/min.

Accuracy

± 0.5% F.S.D. (typical)

Thermal drift (for ambient temperature variation between

- 20° C and + 65° C)

•with 2in diaphragm

- span 30 to 80 kPa (300 to 800 mbar): 0.4%/10°C

- span 80 to 170 kPa (800 to 1700 mbar): 0.3%/10°C

•with 3in diaphragm

- span 5 to 10 kPa (50 to 100 mbar): 0.6%/10°C

- span 10 to 52 kPa (100 to 520 mbar): 0.4%/10°C

Maximum displacement

- with 2in diaphragm: 1 cm3

- with 3in diaphragm: 1.5 cm3

Degree of protection in accordance with IEC 529

IP55

Ambient temperature limits

-40 and + 120°C

Bodies material

Carbon steel, Monel (*), AISI 316L (*), Hastelloy C (*),

(*) Only the positive halfbody

Body bolts and nuts material

High tensile carbon steel;

AISI 316 Class A4-50 per ISO3506, in compliance with

NACE MR0175

OVERRANGE

LIMIT

2.5 MPa

25 bar

MEASURING

CAPSULE

(DIAPHRAGM DIA.)

3 in with special

feedback bellows

30 and 170 kPa

300 and 1700 mbar

5 and 52 kPa

50 and 520 mbar

2.5 and 7.5 kPa

25 and 75 mbar

MAXIMUM

ZERO

SUPPRESSION (S)

140 kPa

1400 mbar

47 kPa

470 mbar

49.5 kPa

495 mbar

RANGE

LIMITS

(absolute)

lower and upper (M)

0 and 170 kPa

0 and 1700 mbar

0 and 52 kPa

0 and 520 mbar

0 and 52 kPa

0 and 520 mbar

SPAN

LIMITS

(absolute)

min. and max.

2 in

3 in

SPECIFICATIONS

The data were obtained from laboratory tests on standard instruments with:

carbon steel or AISI 316L bodies; AISI 316L measuring element with silicone oil filling; gasket: PTFE;

calibration span : 18 kPa - 180 mbar (for 3in diaphragm), 70 kPa - 700 mbar (for 2in diaphragm)

Core

material

hi Diaphragm

material

MEASURING ELEMENT

Span limits

kPa (mmHg) - (Note 1)

Capsule

diameter

Carbon steel

AISI 316L

Carbon steel

Monel

AISI 316L

Hastelloy C

AISI 316L

Monel

AISI 316L

Hastelloy C

Negative side

Positive side

BODY

de VERSION

Standard with body bolts and nuts in high tensile carbon steel

Standard with body bolts and nuts in AISI 316

5 and 52 (37.5 and 390)

30 and 170 (225 and 1275)

2.5 and 7.5 (18.7 and 56.2)

5 and 52 (37.5 and 390)

30 and 170 (225 and 1275)

2.5 and 7.5 (18.7 and 56.2)

5 and 52 (37.5 and 390)

30 and 170 (225 and 1275)

2.5 and 7.5 (18.7 and 56.2)

5 and 52 (37.5 and 390)

30 and 170 (225 and 1275)

2.5 and 7.5 (18.7 and 56.2)

5 and 52 (37.5 and 390)

30 and 170 (225 and 1275)

2.5 and 7.5 (18.7 and 56.2)

3 in

2 in

3 in

2 in

3 in

2 in

3 in

2 in

3 in

2 in

3 in

AISI 316L (*) (Note 2)

Monel (**)

AISI 316L (Note 2)

Hastelloy C (**)

AISI 316L (**)

ORDERING INFORMATION

Select one character or set of characters from each category and specify complete catalog number.

NBC

abc de fg hi j k lm

BASE MODEL

VERSION

BODY

MEASURING ELEMENT

GASKETS

OUTPUT

EXTRAS

PRODUCT CODE

abc BASE MODEL

Code

Absolute pressure transmitter

k3 to 15 psi

3 to 15 psi with zero suppression device

0.2 to 1.0 kg/cm2

0.2 to 1.0 kg/cm2 with zero suppression device

20 to 100 kPa / 0.2 to 1 bar

20 to 100 kPa / 0.2 to 1 bar with zero suppression device

OUTPUT

According to

ANSI/ISA S 51.1-1979

standard terminology

Note 1: Multiply by 10 the value in kPa (MPa) to obtain mbar (bar).

Note 2: Hastelloy C for some wetted parts.

(*) Suitable for oxygen service (operating temperature limits reduced: -20°C to + 40°C; -4°F to 104°F)

(**) Maximum overrange reduced to 1 MPa (145 psi)

Fulcrum

diaphragm gasket

Viton

PTFE (*)

Capsule gasketFlange gasket

(*) Suitable for oxygen service.

Viton

PTFE (*)

Viton

PTFE (*)

GASKETS

Piping

material Air filter

regulator Pressure

gauge

EXTRAS

- -

with

- -

with

Identification

tag material

lm Stainless Steel

Stainless Steel

- -

Stainless Steel

Copper

Stainless Steel

Copper

Compliance to NACE class II bolting, according to specification MR0175, latest revision

The Company's policy is one of continuous product

improvement and the right is reserved to modify the

specifications contained herein without notice.

SS/NBC Rev 7

MOUNTING DIMENSIONS

ABB Inc.

125 East County Line Road

Warminster, Pa 18974

USA

Tel. (215) 674-6000

Facsimile (215) 674-7183

ABB Ltd.

Howard Road

St. Neots, Cambs.

England PE19 8EU

Tel. (01480) 475321

Facsimile (01480) 217948

ABB Instrumentation spa

Via Statale, 113

22016 Lenno (CO)

Italia

Tel. 0344 58111

Facsimile 0344 56278