NBD-Series - ABB Semiconductors

Specification sheet

The blind type absolute pressure transmitter, mod. NBD, 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 a single version with 5in 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

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 the

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

GENERAL CHARACTERISTICS

Model NBD

Absolute pressure

transmitter

Deltapi N Series

Pneumatic Transmitters

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.

OVERRANGE

LIMIT

MEASURING

CAPSULE

DIAMETER

5 in 1.2 and 7.5 kPa

12 and 75 mbar

MAXIMUM

ZERO

SUPPRESSION (S)

6.3 kPa

63 mbar

0 and 7.5 kPa

0 and 75 mbar 0.5 MPa

5 bar

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)

- span 1.2 to 2 kPa (12 to 20 mbar): 0.6%/10°C

- span 2 to 7.5 kPa (20 to 75 mbar): 0.4%/10°C

Maximum displacement

2.5 cm3

Degree of protection in accordance with IEC 529

IP55

Ambient temperature limits

-40 and + 120°C

Bodies material

Carbon steel, AISI 316L

Body bolts and nuts material

High tensile carbon steel;

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

NACE MR0175

SPAN

LIMITS

(absolute)

min. and max.

RANGE

LIMITS

(absolute)

lower and upper (M)

Cover material

thermoplastic resin

Diaphragm material

AISI 316L

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)

15 kg approx

Packing

expanded polythene box

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 : 4 kPa - 40 mbar

Carbon steel

AISI 316L

hi 1.2 and 7.5 (9 and 56)

1.2 and 7.5 (9 and 56)

MEASURING ELEMENT

5 in

AISI 316L

de VERSION

fg BODY

AISI 316L (Note 2)

AISI 316L (*) (Note 2)

Capsule

diameter

Diaphragm

material Core

material

Standard with body bolts and nuts in high tensile carbon steel

Standard with body bolts and nuts in AISI 316

Span limits

kPa (mmHg) - (Note 1)

ORDERING INFORMATION

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

NBD

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

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)

Fulcrum

diaphragm gasket

Viton

PTFE (*)

Capsule gasketFlange gasket

(*) Suitable for oxygen service.

Viton

PTFE (*)

Viton

PTFE (*)

GASKETS

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

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

SS/NBD Rev 7

The Company's policy is one of continuous product

improvement and the right is reserved to modify the

specifications contained herein without notice.

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