Specification sheet

Model NDA

Differential pressure

Deltapi N Series

Pneumatic Transmitters

The blind type dIfferential pressure transmitter, mod. NDA, is

used to measure a differential pressure and convert it into a

proportional pneumatic signal.

force balances that of the measuring element.

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

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

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

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

Oxygen measurements a special degreasing and final test

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.

Thermal drift (for ambient temperature variation between

- span 700 to 3500 kPa (7 to 35 bar): 0.3%/10°C

Bellows C

- span 700 to 1400 kPa (7 to 14 bar): 0.8%/10°C

- span 1400 to 7000 kPa (14 to 70 bar): 0.4%/10°C

Bellows D

- span 1400 to 2800 kPa (14 to 28 bar): 1%/10°C

- span 2800 to 10000 kPa (28 to 100 bar): 0.5%/10°C

Pressure effect for variation of

- Bellows A - 1.75 MPa (17.5 bar): 0.25%

- Bellows B - 3.5 MPa (35 bar): 0.25%

Body bolts and nuts material

high tensile carbon steel;

AISI 316 Class A4-70 per ISO3506;

high tensile stainless steel, in compliance with

AISI 316 L, Monel

PTFE, Viton

Cover material

thermoplastic resin

1/2 in NPT-F

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.

Die cast aluminium alloy with light grey epoxy finish.

lower and upper (M)

min. and max.

170 and 1700 kPa

1.7 and 17 bar

350 and 3500 kPa

3.5 and 35 bar

700 and 7000 kPa

-100 and +100 bar

-100 and +100 bar

(•) Equal to Maximum Working pressure as well as Overrange Limit

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

carbon steel or AISI 316L body and flange; AISI 316L bellows unit; gasket: PTFE;

calibration span: 800 kPa - 8 bar (bellows A), 1700 kPa - 17 bar (bellows B), 3500 kPa - 35 bar (bellows C),

7000 kPa - 70 bar (bellows D).

tag material