Specification sheet Deltapi N Series

Pneumatic Transmitters
Model NAD
Differential pressure
transmitter
GENERAL CHARACTERISTICS
The blind type differential pressure transmitter, mod. NAD, is
used to measure and convert a differential pressure value into
a proportional pneumatic signal.
The instrument works on the force-balance principle and
consists of two main units:

the measuring unit which detects the differential pressure

variation and consists of two forged bodies and a measuring
capsule.
The capsule is available in two versions: 2in or 3in diameter
diaphragms, filled with a special liquid, which can withstand the
maximum overrange pressure on one side without damaging
itself.

the transmission unit converts the differential force applied to

the measuring element into a proportional output pneumatic
signal.
The output pressure, generated by a flapper nozzle relay,
feeds the 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.

Air filter regulator can be directly mounted on the transmitter,

OPTIONAL EXTRA FEATURES with or without pressure gauge, and connected with piping and
fittings either in stainless steel or copper.
A zero elevation or suppression device allows to set as a Special versions of air filter regulator and gauges, in stainless
zero of the transmitter a measured variable value different from steel, are available on request.
zero.
The sum of the zero suppression value (S) plus the calibrated Manifold. The transmitter can be supplied with a 3-valve
span cannot exceed the upper range limit (M) suitable for the manifold block integrally mounted to simplify maintenance and
diaphragm capsule : S + span ≤ M (see table). calibration procedures.
SPECIFICATIONS
The data were obtained from laboratory tests on standard instruments with:
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)

MEASURING SPAN RANGE MAXIMUM MAXIMUM STATIC PRESSURE

CAPSULE LIMITS LIMITS ZERO ZERO LIMITS
(DIAPHRAGM DIA.) min. and max. lower and upper(M) SUPPRESSION (S) ELEVATION Full vacuum and

30 and 170 kPa -170 and +170 kPa 140 kPa 170 kPa
2 in
300 and 1700 mbar -1700 and +1700 mbar 1400 mbar 1700 mbar 41 MPa (•)
410 bar (•)
7 and 52 kPa -52 and +52 kPa 45 kPa 52 kPa
3 in
70 and 520 mbar -520 and +520 mbar 450 mbar 520 mbar

(•) Equal to Maximum Working pressure as well as overrange limit (on either side)

Air supply Cover material

nom. 140 kPa (1.4 bar, 20 psi); min. 125 kPa (1.25 bar, thermoplastic resin
18 psi); max. 175 kPa (1.75 bar, 25 psi)
Diaphragm material
Output signal AISI 316L
20 to 100 kPa/0.2 to 1 bar, 3 to 15 psi or 0.2 to 1 kg/cm2
Gaskets material
Static air consumption PTFE, Viton
350 Nl/h
Capsule filling
Maximum output flow Silicone oil, Perfluorinated polyethers (Galden)
- with rising output pressure: 30 Nl/min.
- with falling output pressure: 40 Nl/min. Surface protections
- carbon steel body and flange: zinc plating and chrome
Accuracy passivation
± 0.5% F.S.D. (typical) - AISI 316L body and flange: no protection

Thermal drift (for ambient temperature variation between Process connections (see figure ref. D and E)
-20° C and + 65° C) - on flanges: 1/2 in NPT-F
• with 2 in diaphragm - on adapters: 1/4 in NPT-F
- span 30 to 80 kPa (300 to 800 mbar): 0.4%/10°C - center distance: 54 mm.
- span 80 to 170 kPa (800 to 1700 mbar): 0.2%/10°C
• with 3 in diaphragm Pneumatic connections
- span 7 to 10 kPa (70 to 100 mbar): 0.6%/10°C - Air supply (in figure ref. A): 1/4 in NPT-F
- span 10 to 52 kPa (100 to 520 mbar): 0.2%/10°C - Output (in figure ref. B): 1/4 in NPT-F

Static pressure effect Pressure gauge

for variation of 40 MPa (400 bar): ≤ ± 1% Brass with stainless steel case (all stainless steel on request)
external diameter 51 mm; 0-200 kPa, 0-2 bar and 0-30 psi
Maximum displacement indication on 82 mm/260° scale.
- with 2 in diaphragm: 1 cm3
- with 3 in diaphragm: 1.5 cm3 Air filter regulator
with copper or stainless steel piping, as specified.
Degree of protection in accordance with IEC 529 Die cast aluminium alloy with light grey epoxy finish.
IP55
Net weight (maximum)
Ambient temperature limits 18 kg approx
-40 and + 120°C
Packing
Bodies material expanded polythene box
Carbon steel, AISI 316L

Body bolts and nuts material

High tensile carbon steel;
17-4-PH in compliance with NACE MR0175
ORDERING INFORMATION
Select one character or set of characters from each category and specify complete catalog number.

PRODUCT CODE abc de fg hi j k lm

BASE MODEL
VERSION
BODY
MEASURING ELEMENT
GASKETS
OUTPUT
EXTRAS

Code

abc BASE MODEL

Differential pressure transmitter NAD

de VERSION
Standard with body bolts and nuts in high tensile carbon steel 01
As 01 with integrally mounted manifold (to be quoted separately) 07
Standard with body bolts and nuts in 17-4-PH 21
As 21 with integrally mounted manifold (to be quoted separately) 27

fg BODY
Carbon steel 01
AISI 316L 11

MEASURING ELEMENT
Diaphragm Core Capsule Capsule Span limits
hi material material filling diameter kPa (inH2O) - (Note 1)
AISI 316L AISI 316L (Note 2) Silicone oil 3 in 7 and 52 (28 and 208) 01
AISI 316L AISI 316L (Note 2) Silicone oil 2 in 30 and 170 (120 and 682) 02
AISI 316L AISI 316L (Note 2) Inert fill 3 in 7 and 52 (28 and 208) 04
AISI 316L AISI 316L (Note 2) Inert fill 2 in 30 and 170 (120 and 682) 05
Note 1: Multiply by 10 the value in kPa (MPa) to obtain mbar (bar).
Note 2: Hastelloy C for some wetted parts.

GASKETS
j Flange gasket Capsule gasket Fulcrum diaphragm gasket
PTFE PTFE Viton 2
PTFE PTFE PTFE 5

k OUTPUT
3 to 15 psi 1
3 to 15 psi with zero elevation device 2
3 to 15 psi with zero suppression device 3
0.2 to 1.0 kg/cm2 According to 4
0.2 to 1.0 kg/cm2 with zero elevation device ANSI/ISA S 51.1-1979 5
0.2 to 1.0 kg/cm2 with zero suppression device standard terminology 6
20 to 100 kPa / 0.2 to 1 bar 7
20 to 100 kPa / 0.2 to 1 bar with zero elevation device 8
20 to 100 kPa / 0.2 to 1 bar with zero suppression device 9

EXTRAS
Identification Piping Air filter Pressure
lm tag material material regulator gauge
Stainless Steel -- -- -- 02
Stainless Steel Stainless Steel with -- 10
Stainless Steel Copper with -- 11
Stainless Steel Stainless Steel with with 13
Stainless Steel Copper with with 14

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

 MOUNTING DIMENSIONS

SS/NAD 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.

ABB Ltd. ABB Inc. ABB Instrumentation spa

Howard Road 125 East County Line Road Via Statale, 113
St. Neots, Cambs. Warminster, Pa 18974 22016 Lenno (CO)
England PE19 8EU USA Italia
Tel. (01480) 475321 Tel. (215) 674-6000 Tel. 0344 58111
Facsimile (01480) 217948 Facsimile (215) 674-7183 Facsimile 0344 56278