Pressure

Differential pressure gauge

With integrated working pressure indication (DELTA-plus)
Model DPG40
WIKA data sheet PM 07.20

for further approvals see

page 5
DELTA-plus

Applications

Monitoring of filtration, flow and level for:

■ Boilers and pressure vessels
■ Drinking and cooling-water treatment plants
■ Pressure-boosting and pumping stations
■ Heating technology
■ Fire-extinguishing systems

Special features
■ Shatterproof window and robust aluminium or stainless
steel measuring chamber for increased requirements
■ Low scale ranges from 0 ... 160 mbar
■ High accuracy down to 1.6 %
■ Optionally with approvals for hazardous areas
Fig. left: With aluminium measuring chamber
■ Helium leak tested
Fig. right: With stainless steel measuring chamber

Description

The differential pressure gauges of the DELTA-line product Furthermore, this saves on an additional measuring and
family are primarily used for the monitoring of low differential sealing point, reducing additional expense for piping and
pressures where there are high requirements in terms of mounting.
one-sided overload and static pressure.
Typical markets for these products are the process heating As a result of the low scale range of 0 … 160 mbar, the
technology, the heating, ventilation and air-conditioning instrument can also be used for applications with low differ-
industries, the water/wastewater industry, and machine build- ential pressures. A further key feature is the high accuracy of
ing and plant construction. For these, the main function of the down to 1.6 % which is important for most applications.
measuring instruments is the monitoring of filters, compres-
sors and pumps. The measuring chamber, depending on the requirement and
application, can be made from aluminium or stainless steel.
Often in these applications, alongside the indication of Through the increased stability, the stainless steel measuring
the differential pressure, the current working pressure is chamber is also suitable for gaseous media.
also relevant. A version with integrated working pressure
indication is therefore available for the model DPG40. The
two easily readable, mechanical on-site displays enable
the simultaneous reading of the working and the differential
pressure.

WIKA data sheet PM 07.20 ∙ 12/2021 Page 1 of 8

Data sheets showing similar products:

DELTA-comb, differential pressure gauge with micro switches; model DPGS40; see data sheet PV 27.20
DELTA-switch, differential pressure switch; model DPS40; see data sheet PV 27.21
DELTA-trans, differential pressure gauge with output signal; model DPGT40; see data sheet PV 17.19
Operating principle
 
The display case (1) is connected directly with the measuring
chamber (2) and the process connections integrated in it.

Pressures p1 and p2 act on the media chambers ⊕ and ⊖,

which are separated by an elastic diaphragm (3). 

The differential pressure (∆p = p1 - p2) leads to an axial

deflection of the diaphragm against the measuring range
springs (4).

The deflection, which is proportional to the differential 
pressure, is transmitted to the movement (7) in the display

14077369.01
case via a pressure-tight and low-friction rocker arm (6).

Overload safety is provided by metal bolsters (5) resting  ⊖ ⊕
against the elastic diaphragm.

Overview of versions
Measuring chamber material Working pressure indication Ex approval
Aluminium Stainless steel Without Ø 22 mm
x x Option
x x -
x x Option

→ For information on approvals, see page 5

Specifications

Basic information
Nominal size
Differential pressure display Ø 100 mm
Working pressure indication ■ Without
■ Ø 22 mm

Window Plastic, with plug screw for switch point setting

Case version Display case, aluminium, EN AC-AI Si9Cu3(Fe)
→ Measuring chamber, see table “measuring element”

Measuring element
Type of measuring element
Differential pressure display Measuring chamber with diaphragm and media chambers ⊕ and ⊖
Working pressure indication ■ Without
■ Bourdon tube

Material
Measuring chamber (differential pressure display) ■ Aluminium, EN AC–Al Si9Cu3(Fe), black painted
■ Stainless steel 1.4571

Diaphragms, sealings ■ FPM/FKM

■ NBR

Bourdon tube (working pressure indication) Copper alloy

Leak tightness of measuring chamber Helium tested, leakage rate: < 5∙10-3 mbar l/s

WIKA data sheet PM 07.20 ∙ 12/2021 Page 2 of 8

 Accuracy specifications
Accuracy class
Differential pressure display ■ 2.5
■ 1.6 (only selectable for scale ranges from 0 ... 1 bar to 0 ... 10 bar)

Working pressure indication 4

Temperature error On deviation from the reference conditions at the measuring system:
max. ±0.8 %/10 K of full scale value
Zero point setting External, via adjustment screw under the window
Reference conditions
Ambient temperature +20 °C

Scale ranges for differential pressure Scale ranges for working pressure
Scale range Scale range
mbar psi bar
0 ... 160 0 ... 5 0 ... 10
0 ... 250 0 ... 15 0 ... 16
0 ... 400 0 ... 25 0 ... 25
0 ... 600 0 ... 40
0 ... 1,000 0 ... 60
bar kg/cm2
0 ... 0.25 0 ... 0.25
0 ... 0.4 0 ... 0.4
0 ... 0.6 0 ... 0.6
0 ... 1 0 ... 1
0 ... 1.6 0 ... 1.6
0 ... 2.5 0 ... 2.5
0 ... 4 0 ... 4
0 ... 6 0 ... 6
0 ... 10 0 ... 10
kPa MPa
-12.5 ... +12.5 0 ... 0.025
0 ... 16 0 ... 0.04
0 ... 25 0 ... 0.06
0 ... 40 0 ... 0.1
0 ... 60 0 ... 0.16
0 ... 100 0 ... 0.25
0 ... 160 0 ... 0.4
0 ... 250 0 ... 0.6
0 ... 400 0 ... 1
0 ... 600
0 ... 1,000

WIKA data sheet PM 07.20 ∙ 12/2021 Page 3 of 8

Further information on: Scale ranges
Special scale ranges Other scale ranges on request
Unit ■ bar
■ psi
■ mbar
■ kg/cm²
■ MPa
■ kPa
Dial
Scale colour Black
Material Aluminium
Special scales Other scales on request
Pointer Blue

Process connections
Standard ■ EN 837
■ DIN EN ISO 8434-1

Size
EN 837 ■ 2 x G ¼, female thread, centre distance 26 mm
■ 2 x G ¼ B, male thread, centre distance 26 mm

DIN EN ISO 8434-1 ■ 2 x compression fitting with ferrule for pipe ∅ 6 mm

■ 2 x compression fitting with ferrule for pipe ∅ 8 mm
■ 2 x compression fitting with ferrule for pipe ∅ 10 mm

Materials (wetted)
Measuring chamber (differential pressure display) ■ Aluminium, Al Si9Cu3(Fe), black painted
■ Stainless steel 1.4571

Process connection ■ Identical to measuring chamber (only 2 x G ¼ female thread)

■ Copper alloy
■ Stainless steel
■ Steel (only compression fittings with ferrule)
Diaphragms, sealings ■ FPM/FKM
■ NBR

Bourdon tube (working pressure indication) Copper alloy

Operating conditions
Medium temperature -10 ... +90 °C [14 ... 194 °F]
Ambient temperature ■ -10 ... +70 °C [14 ... 150 °F] for Non-Ex instruments
■ -10 ... +60 °C [14 ... 140 °F] for Ex instruments

Storage temperature -20 ... +60 °C [-4 ... +140 °F]

Pressure limitation
Steady Full scale value
Fluctuating 0.9 x full scale value
Overload safety Max. 25 bar
On one, both and alternatingly on the ⊕ and ⊖ sides
Ingress protection per IEC/EN 60529 IP65

WIKA data sheet PM 07.20 ∙ 12/2021 Page 4 of 8

Approvals

Approvals included in the scope of delivery

Logo Description Country
- CRN Canada
Safety (e.g. electr. safety, overpressure, ...)

Optional approvals
Logo Description Country
EU declaration of conformity European Union
ATEX directive
Hazardous areas
- Ex h Gas II 2G Ex h IIC T6 ... T1 Gb X
Dust II 2D Ex h IIIC T85 °C T450 °C Db X

EAC Eurasian Economic Community

Hazardous areas
Ex Ukraine Ukraine
Hazardous areas
PAC Russia Russia
Metrology, measurement technology
- PAC Ukraine Ukraine
Metrology, measurement technology

Certificates (option)
Certificates
Certificates ■ 2.2 test report per EN 10204 (e.g. state-of-the-art manufacturing, indication accuracy)
■ 3.1 inspection certificate per EN 10204 (e.g. indication accuracy)

Recommended recalibration interval 1 year (dependent on conditions of use)

→ Approvals and certificates, see website

WIKA data sheet PM 07.20 ∙ 12/2021 Page 5 of 8

Dimensions in mm

Model DPG40 with aluminium measuring chamber, 2 x G ¼ female thread, centre distance 26 mm

120 22
4 6 4.4

114-117

27
100

30
14
13

G1/4
20,5 15

14077751.01
26 Weight
approx. 1.3 kg

Model DPG40 with stainless steel measuring chamber, 2 x G ¼ female thread, centre distance 26 mm

125 132
4 5,5 4,8

116
100

30

30
56

45
15
13

G1/4
14412474.01

20,5
Weight
26 15 approx. 3.7 kg

WIKA data sheet PM 07.20 ∙ 12/2021 Page 6 of 8

Model DPG40, 2 x compression fitting with ferrule Model DPG40, 2 x G ¼ B, male thread

19
19

13
2
17

14077971.01
5
for pipe ∅ 6, 8 and 10 mm 10
G1/4B

Accessories and spare parts

Model Description Order number

- Panel mounting flange, aluminium 14074004

Panel mounting flange, stainless steel 14075088

910.17 Sealings -
→ See data sheet AC 09.08

910.15 Syphons -
→ See data sheet AC 09.06

IV3x 4-way valve block, stainless steel 2043559

→ For dimensions see page 8

4-way valve block, brass 2043567

→ For dimensions see page 8

- Compression fittings with ferrule or clamp ring for pipe diameters 6, 8 On request
and 10 mm
6, 8 and 10 mm

WIKA data sheet PM 07.20 ∙ 12/2021 Page 7 of 8

 Dimensions in mm

4-valve manifold

6 26
Pressure compensating valve
≈ 37,5

23
Vent valve

25

98

42
38

22

2261821.01
G1/8 Shut-off valve G1/4 Shut-off valve
⊕ side ⊖ side
30 30
≈ 105 50

Ordering information
Model / Scale range / Process connection / Material of diaphragm and sealings / Options

© 11/2007 WIKA Alexander Wiegand SE & Co. KG, all rights reserved.
The specifications given in this document represent the state of engineering at the time of publishing.
We reserve the right to make modifications to the specifications and materials.

WIKA data sheet PM 07.20 ∙ 12/2021 Page 8 of 8

12/2021 EN

WIKA Alexander Wiegand SE & Co. KG

Alexander-Wiegand-Straße 30
63911 Klingenberg/Germany
Tel. +49 9372 132-0
Fax +49 9372 132-406
info@wika.de
www.wika.de