Grundfos DMH 251, DMH 252, DMH 253, DMH 254, DMH 255 Installation And Operating Instructions Manual

DMH 25x

Dosing pump

GRUNDFOS ALLDOS INSTRUCTIONS

Installation and operating instructions

Declaration of Conformity

We Grundfos Alldos declare under our sole responsibility that the
products DMH 251, DMH 252, DMH 253, DMH 254, DMH 255, DMH 256
and DMH 257, to which this declaration relates, are in conformity with the
Council Directives on the approximation of the laws of the EC Member
States relating to

— Machinery (98/37/EC).

Standard used: EN ISO 12100.

— Electromagnetic compatibility (89/336/EEC).

Standards used: EN 61000-3-2: 1995, + A1 + A2, EN 61000-3-3: 1995
and EN 61326: 1997, + A1 + A2, Class B.

— Electrical equipment designed for use within certain voltage limits

(73/23/EEC) [95].
Standard used: EN 61010-1: 2002.

Pfinztal, 15th November 2007

W. Schwald

Managing Director

Ulrich Stemick

Technical Director

2

3

CONTENTS

Page

1. General 3

1.1 Introduction 3

1.2 Service documentation 3

2. Installation data 4

3. Installation sketch 4

4. General information 5

4.1 Applications 5

4.2 Warranty 5

5. Safety 5

5.1 Identification of safety instructions in this manual 5

5.2 Qualification and training of personnel 5

5.3 Risks when safety instructions are not observed 5

5.4 Safety-conscious working 5

5.5 Safety instructions for the operator/user 5

5.6 Safety instructions for maintenance, inspection and
installation work 5

5.7 Unauthorised modification and manufacture of
spare parts 6

5.8 Improper operating methods 6

5.9 Safety of the system in the event of a failure in
the dosing system 6

6. Technical data 6

6.1 Identification 6

6.2 Type key 7

6.3 Pump types 8

6.4 Pump performance 8

6.5 Sound pressure level 11

6.6 Electrical data 11

6.7 AR control unit 11

6.8 Required energy 11

6.9 Ambient and operating conditions 11

6.10 Dosing medium 11

7. Transport and storage 12

7.1 Delivery 12

7.2 Unpacking 12

7.3 Intermediate storage 12

7.4 Return 12

8. Product description and accessories 13

8.1 General description 13

8.2 Dimensional sketches 17

8.3 Weight 19

8.4 Stroke volume 19

8.5 Materials 19

8.6 Data of contact pressure gauge for diaphragm
leakage detection (optional) 19

9. Installation 19

9.1 General information on installation 19

9.2 Installation location 19

9.3 Mounting 19

9.4 Approximate values when using pulsation dampers 20

9.5 Optimum installation 21

9.6 Installation tips 21

9.7 Tube / pipe lines 22

9.8 Connecting the suction and discharge lines 22

10. Electrical con necti ons 23

10.1 Electric servomotor (optional) 23

10.2 Electronic preselection counter (optional) 23

10.3 Electrically heated dosing head (optional) 23

10.4 Diaphragm controller (optional) 24

10.5 Connecting the power supply cable 24

11. Start-up / shutdown 24

11.1 Initial start-up / subsequent start-up 24

11.2 Start-up / subsequent start-up of
DMH 251, 252 and 253 25

11.3 Start-up / subsequent start-up of
DMH 254, 255 and 257 25

11.4 Setting the pressure relief valve 26

11.5 Zero point adjustments 27

11.6 Operating the pump 27

11.7 Shutdown 27

12. Operation 27

12.1 Switching on/off 27

12.2 Setting the dosing capacity 28

12.3 Using the AR control unit (optional) 28

12.4 Electric servomotor (optional) 28

12.5 Electronic preselection counter (optional) 28

12.6 Electrically heated dosing head (optional) 28

13. Maintenance 28

13.1 General notes 28

13.2 Diaphragm leakage control for diaphragm leakage
detection 28

13.3 Cleaning and maintenance intervals 29

13.4 Checking the oil level 29

13.5 Cleaning the suction and discharge valves 29

13.6 Replacing the diaphragm and gear oil for dosing head
with single diaphragm
(no diaphragm leakage detection) 30

13.7 Replacing the diaphragm for dosing head with
double diaphragm 31

14. Fault finding chart 34

15. Dosing curves 36

16. Disposal 49

1. General

1.1 Introduction

These installation and operating instructions contain all the
information required for starting up and handling the DMH 25x
piston diaphragm dosing pump.

If you require further information or if any problems arise, which
are not described in detail in this manual, please contact the
nearest Grundfos Alldos company.

1.2 Service documentation

If you have any questions, please contact the nearest Grundfos
Alldos company or service workshop.

Warning
These complete installation and operating

instructions are also available on
www.Grundfosalldos.com.

Prior to installation, read these installation and
operating instructions. Installation and operation
must comply with local regulations and accepted
codes of good practice.

4

2. Installation data

Owner:

Grundfos Alldos customer number:

Order number:

Product number:

Pump serial number:

Put into service on:

Location of pump:

Used for:

3. Installation sketch

Note

Please fill in the data below after commissioning.
It will help you and your Grundfos Alldos service
partner to make subsequent adjustments to the
installation.

5

4. General information

4.1 Applications

The DMH 25x pump is suitable for liquid, non-abrasive and non­inflammable media strictly in accordance with the instructions in
this manual.

4.2 Warranty

Warranty in accordance with our general terms of sale and
delivery is only valid

• if the pump is used in accordance with the information within
this manual.

• if the pump is not dismantled or incorrectly handled.

• if repairs are carried out by authorised and qualified
personnel.

• if original spare parts are used for repairs.

5. Safety

This manual contains general instructions that must be observed
during installation, operation and maintenance of the pump. This
manual must therefore be read by the installation engineer and
the relevant qualified personnel/operators prior to installation and
start-up, and must be available at the installation location of the
pump at all times.

It is not only the general safety instructions given in this "Safety"
section that must be observed, but all special safety instructions
given in the other sections.

5.1 Identification of safety instructions in this manual

If the safety instructions or other advice in this manual are not
observed, it may result in personal injury or malfunction and
damage to the pump. The safety instructions and other advice are
identified by the following symbols:

Information provided directly on the pump, e.g. labelling of fluid
connections, must be maintained in a readable condition at all
times.

5.2 Qualification and training of personne l

The personnel responsible for the operation, maintenance,
inspection and installation must be appropriately qualified for
these tasks. Areas of responsibility, levels of authority and the
supervision of the personnel must be precisely defined by the
operator.

If the personnel do not have the necessary knowledge, the
necessary training and instruction must be given. If necessary,
training can be performed by the manufacturer/supplier at the
request of the operator of the pump. It is the responsibility of the
operator to make sure that the contents of this manual are
understood by the personnel.

5.3 Risks when safety instructions are not observed

Non-observance of the safety instructions may have dangerous
consequences for the personnel, the environment and the pump.
If the safety instructions are not observed, all rights to claims for
damages may be lost.

Non-observance of the safety instructions may lead to the
following hazards:

• failure of important functions of the pump/system

• failure of specified methods for maintenance

• harm to humans from exposure to electrical, mechanical and
chemical influences

• damage to the environment from leakage of harmful
substances.

5.4 Safety-conscious working

The safety instructions in this manual, applicable national health
and safety regulations and any operator internal working,
operating and safety regulations must be observed.

5.5 Safety instructions for the operator/user

Hazardous hot or cold parts on the pump must be protected to
prevent accidental contact.

Leakages of dangerous substances (e.g. hot, toxic) must be
disposed of in a way that is not harmful to the personnel or the
environment. Legal regulations must be observed.

Damage caused by electrical energy must be prevented (for more
details, see for example the regulations of the VDE and the local
electricity supply company).

5.6 Safety instructions for maintenance, inspection

and installation work

The operator must ensure that all maintenance, inspection and
installation work is carried out by authorised and qualified
personnel, who have been adequately trained by reading this
manual.

All work on the pump should only be carried out when the pump is
stopped. The procedure described in this manual for stopping the
pump must be observed.

Pumps or pump units which are used for media that are harmful
to health must be decontaminated.

All safety and protective equipment must be immediately
restarted or put into operation once work is complete.

Observe the points described in the initial start-up section prior to
subsequent start-up.

Note

Explosion-proof pumps are identified from the
pump and motor nameplates. An EC declaration
of conformity is provided in accordance with the
EC directive 94/9/EC, the so-called ATEX
directive. This declaration of conformity replaces
the declaration of conformity in this manual.

Warning
To operate a pump which has been identified as

an explosion-proof pump for the dosing of
inflammable media or for operation in potentially
explosive operating sites in accordance with the
EC directive 94/9/EC, refer to the enclosed
manual "Operating an explosion-proof pump" in
addition to this manual.

Warning
Other applications or the operation of pumps in

ambient and operating conditions, which are not
approved, are considered improper and are not
permitted. Grundfos Alldos accepts no liability
for any damage resulting from incorrect use.

Warning
If these safety instructions are not observed,

it may result in personal injury!

Caution

If these safety instructions are not observed,
it may result in malfunction or damage to the
equipment!

Note

Notes or instructions that make the job easier
and ensure safe operation.

Warning
The pump must be installed in a position where

it is easily accessible during operation and
maintenance work.

Observe the flow direction of valves (indicated by
an arrow on the valve)!

Only tighten plastic valves by hand.
Only use the prescribed line types!
Electrical connections must only be carried out

by qualified personnel!

6

5.7 Unauthorised modification and manufacture of
spare parts

Modification or changes to the pump are only permitted following
agreement with the manufacturer. Original spare parts and
accessories authorised by the manufacturer are safe to use.
Using other parts can result in liability for any resulting
consequences.

5.8 Improper operating methods

The operational safety of the supplied pump is only ensured if it is
used in accordance with section 6. Technical data. The specified
limit values must under no circumstances be exceeded.

If the assumption is made that a safe operation is no longer
possible, switch off the pump and protect it against
unintentional operation.

This action should be taken

• if the pump has been damaged.

• if the pump no longer seems to be operational.

• if the pump has been stored for an extended period of time

in poor conditions.

5.9 Safety of the system in the event of a failure
in the dosing system

DMH 25x dosing pumps are designed according to the latest
technologies and are carefully manufactured and tested.
However, a failure may occur in the dosing system. Systems in
which dosing pumps are installed must be designed in such a
way that the safety of the entire system is still ensured following a
failure of the dosing pump. Provide the relevant monitoring and
control functions for this.

6. Technical data

6.1 Identification

Fig. 1 DMH nameplate

Warning
Make sure that the pump is suitable for the actual

dosing medium!
Observe the chemical manufacturer's safety

instructions when handling chemicals!
Do not operate the pump next to closed valves.

Warning
The pump housing, control unit and sensors

must only be opened by personnel authorised by
Grundfos Alldos!

Repairs must only be carried out by authorised
and qualified personnel!

Wear protective clothing (gloves and goggles)
when working on the dosing head, connections
or lines!

Before removing the dosing head, valves and
lines, empty any remaining medium in the dosing
head into a drip tray by carefully unscrewing the
suction valve.

Caution

The resistance of the parts that come into contact
with the media depends on the media, media
temperature and operating pressure. Ensure that
parts in contact with the media are chemically
resistant to the dosing medium under operating
conditions!

Note

Explosion-proof pumps are identified from the
pump and motor nameplates. An EC declaration
of conformity is provided in accordance with the
EC directive 94/9/EC, the so-called ATEX
directive. This declaration of conformity replaces
the declaration of conformity in this manual.

Warning
To operate a pump which has been identified as

an explosion-proof pump for the dosing of
inflammable media or for operation in potentially
explosive operating sites in accordance with the
EC directive 94/9/EC, refer to the enclosed
manual "Operating an explosion-proof pump" in
addition to this manual.

TM03 8688 2207

Pos. Description

1 Type designation
2 Model
3 Maximum capacity [l/h]
4 Voltage [V]
5 Frequency [Hz]
6 Product number
7 Country of origin
8 Year and week code

9 Marks of approval, CE mark, etc.
10 Maximum pressure [bar]
11 Serial number

7

6.2 Type key

* Only pumps up to and including 0.37 kW and only single-phase pumps

Example:

DMH 100

- 10

AR PP /E /T -F -G 1

B9B9

FE0

Type range Motor variant

DMH E0 PTC motor for frequency control

Maximum flow [l/h]

E1 Motor type EEx de C T3, 3 x 400 V, 50 Hz

Maximum pressure [bar]
Control variant

E2 Motor type EEx de C T4, 3 x 400 V, 50 Hz

B Standard E3 API approval

AR* AR control unit (analog/pulse control)

Mains plug

S1 Stroke output X No plug

AT0 Prepared for servomotor F EU (Schuko)

AT3

Servomotor, 1 x 230 V, 50/60 Hz supply,
4-20 mA control

B USA, Canada

I Australia, New Zealand, Taiwan

AT5

Servomotor, 1 x 115 V, 50/60 Hz supply,
4-20 mA control

E Switzerland

Connection, suction/discharge

AT6

Servomotor, 1 x 230 V, 50/60 Hz supply,
4-20 mA control, EEx d II BT 4

B6 Pipe, 4/6 mm

C2 Pipe, 8/10 mm

AT7

Servomotor, 1 x 115 V, 50/60 Hz supply,
4-20 mA control, EEx d II BT 4

C4 Pipe, 20/25 mm

4 Tube, 6/9 mm

AT8

Servomotor, 1 x 230 V, 50/60 Hz supply,
4-20 mA control, 1 kΩ potentiometer

6 Tube, 9/12 mm

B9 Tube, 19/27 mm, PVC

AT9

Servomotor, 1 x 115 V, 50/60 Hz supply,
4-20 mA control, 1 kΩ potentiometer

Q Tube, 19/27 mm and 25/34 mm

S Tube, 3/8" / 1/2"

Dosing head variant

A Threaded, Rp 1/4, female

PP Polypropylene A1 Threaded, Rp 3/4, female

PV PVDF (polyvinylidene fluoride) V Threaded, 1/4" NPT, female

PVC Polyvinyl chloride A9 Threaded, 1/2" NPT, male

SS Stainless steel, DIN 1.4571 A3 Threaded, 3/4" NPT, female

Y Hastelloy® C A7 Threaded, 3/4" NPT, male

PP-L PP + integrated diaphragm leakage detection

B8 Cementing d. 40 mm and flange DN 32

PV-L PVDF + integrated diaphragm leakage detection

PVC-L PVC + integrated diaphragm leakage detection B1 Tube 6/12 mm/cementing d. 12 mm

SS-L SS + integrated diaphragm leakage detection

B2 Tube 13/20 mm/cementing d. 25 mm

Y-L Y + integrated diaphragm leakage detection

SS-H SS + heating flange in dosing head (electric) B3 Welding d. 16 mm

Gasket material

B4 Welding d. 25 mm

E EPDM B7 Welding d. 40 mm and flange DN 32

VFKM C1 Welding flange DN 32, stainless steel

TPTFE P Flange 1 1/4"

Valve ball material

Valve type

C Ceramics 1 Standard

GGlass 2

Spring-loaded

0.05 bar suction opening pressure;

0.05 bar discharge opening pressure

T

PTFE

3

Spring-loaded

0.05 bar suction opening pressure;

0.8 bar discharge opening pressure

SS Stainless steel, DIN 1.4401

Y Hastelloy

®

C 4

Spring-loaded, discharge side only,

0.8 bar opening pressure

Control panel position

5 For abrasive media

X No control panel

Supply voltage

F Front-mounted (opposite to the dosing head) 0 Without motor, IEC flange

S Side-mounted (same side as the stroke-length adjustment knob) F Without motor, NEMA flange (US)

Sx Side-mounted (side opposite to the stroke-length adjustment knob) G 1 x 230 V, 50/60 Hz

W Wall-mounted H 1 x 120 V, 50/60 Hz

5 3 x 230/460 V, 60 Hz

E

230/400 V, 50/60 Hz
440/480 V, 60 Hz

K 3 x 500 V 50 Hz

8

6.3 Pump types

The DMH 25x dosing pump is available for a variety of
performance ranges in various sizes. Pump type and designation,
see pump nameplate.

The following is indicated on the pump nameplate (see section

6.1 Identification):

• The pump type which specifies the stroke volume, connection
size and performance data (see below).

• The pump serial number which is used to identify the pump.

• The most important characteristics of the pump configuration
e.g. for dosing head and valve materials. They are described
in section 6.2 Type key.

• Maximum flow rate and maximum counter-pressure.

• Mains frequency.

The following is indicated on the motor nameplate:

• required energy

• mains frequency

• power consumption

• enclosure class.

6.4 Pump performance

Performance data at maximum pump counter-pressure

Pump type 50 Hz 60 Hz 100 Hz

Single pump Double pump

Q* p max.

Max.

stroke

rate

Q* p max.

Max.

stroke

rate

Q* p max.

Max.

stroke

rate

[l/h] [bar] [n/min] [l/h] [bar] [n/min] [l/h] [bar] [n/min]

DMH 251

DMH 2.4-10 DMH 2.4-10/2.4-10 2.4 10 14 2.9 10 17 5 10 29
DMH 5-10 DMH 5-10/5-10 5 10 29 6 10 35 10 10 58
DMH 13-10 DMH 13-10/13-10 13 10 63 16 10 75 25 10 126
DMH 19-10 DMH 19-10/19-10 19 10 96 23 10 115 — — —
DMH 24-10 DMH 24-10/24-10 24 10 120 — — — — — —
DMH 2.3-16 DMH 2.3-16/2.3-16 2.3 16 14 2.8 16 17 4.5 16 29
DMH 4.9-16 DMH 4.9-16/4.9-16 4.9 16 29 5.9 16 35 9.8 16 58
DMH 12-16 DMH 12-16/12-16 12 16 63 14 16 75 24 16 126
DMH 18-16 DMH 18-16/18-16 18 16 96 22 16 115 — — —
DMH 23-16 DMH 23-16/23-16 23 16 120 — — — — — —
DMH 2.2-25 DMH 2.2-25/2.2-25 2.2 25 14 2.6 25 17 4.4 25 29
DMH 4.5-25 DMH 4.5-25/4.5-25 4.5 25 29 5.4 25 35 9 25 58
DMH 11-25 DMH 11-25/11-25 11 25 63 13 25 75 22 25 126
DMH 17-25 DMH 17-25/17-25 17 25 96 20 25 115 — — —
DMH 21-25 DMH 21-25/21-25 21 25 120 — — — — — —

DMH 252

DMH 11-10 DMH 11-10/11-10 111029131035221058
DMH 24-10 DMH 24-10/24-10 24 10 63 29 10 75 48 10 126
DMH 37-10 DMH 37-10/37-10 37 10 96 44 10 115 — — —
DMH 46-10 DMH 46-10/46-10 46 10 120 — — — — — —
DMH 10-16 DMH 10-16/10-16 10 16 29 12 16 35 20 16 58
DMH 23-16 DMH 23-16/23-16 23 16 63 27 16 75 46 16 126
DMH 36-16 DMH 36-16/36-16 36 16 96 43 16 115 — — —
DMH 45-16 DMH 45-16/45-16 45 16 120 54 16 144 — — —
DMH 54-16 DMH 54-16/54-16 54 16 144 — — — — — —

DMH 253

DMH 21-10 DMH 21-10/21-10 21 10 29 25 10 35 46 10 58
DMH 43-10 DMH 43-10/43-10 43 10 63 52 10 75 87 10 126
DMH 67-10 DMH 67-10/67-10 67 10 96 78 10 115 — — —
DMH 83-10 DMH 83-10/83-10 83 10 120 99 10 144 — — —
DMH 100-10 DMH 100-10/100-10 100 10 144 — — — — — —

DMH 254

DMH 50-10 DMH 50-10/50-10 50 10 26 60 10 31 101 10 52
DMH 102-10 DMH 102-10/102-10 102 10 54 122 10 65 203 10 108
DMH 143-10 DMH 143-10/143-10 143 10 75 172 10 90 286 10 150
DMH 175-10 DMH 175-10/175-10 175 10 92 210 10 110 — — —

9

* l/h per dosing head; double the capacity for double pumps.

6.4.1 Accuracy

• Dosing flow fluctuation: smaller than ± 1 %

• Linearity deviation: ± 1 % of the full-scale value (for water with
a fully deaerated dosing head).

6.4.2 Inlet pressure and counter-pressure / suction lift

Maximum inlet pressure

Minimum counter-pressure at the discharge valve of the
pump

DMH 213-10 DMH 213-10/213-10 213 10 112 255 10 134 — — —
DMH 291-10 DMH 291-10/291-10 291 10 153 — — — — — —
DMH 46-16 DMH 46-16/46-16 46 16 26 55 16 31 92 16 52
DMH 97-16 DMH 97-16/97-16 97 16 54 116 16 65 193 16 108
DMH 136-16 DMH 136-16/136-16 136 16 75 163 16 90 271 16 150
DMH 166-16 DMH 166-16/166-16 166 16 92 200 16 110 — — —
DMH 202-16 DMH 202-16/202-16 202 16 112 242 16 134 — — —
DMH 276-16 DMH 276-16/276-16 276 16 153 — — — — — —

DMH 255

DMH 194-10 DMH 194-10/194-10 194 10 54 233 10 65 387 10 108
DMH 270-10 DMH 270-10/270-10 270 10 75 324 10 90 540 10 150
DMH 332-10 DMH 332-10/332-10 332 10 92 398 10 110 — — —
DMH 403-10 DMH 403-10/403-10 403 10 112 484 10 134 — — —
DMH 550-10 DMH 550-10/550-10 550 10 153 — — — — — —

DMH 257

DMH 220-10 DMH 220-10/220-10 220 10 28 264 10 34 440 10 56
DMH 440-10 DMH 440-10/440-10 440 10 56 528 10 67 880 10 112
DMH 575-10 DMH 575-10/575-10 575 10 73 690 10 88 1150 10 146
DMH 750-4 DMH 750-4/750-4 750 4 73 900 4 88 1500 4 146
DMH 770-10 DMH 770-10/770-10 770 10 98 924 10 118 — — —
DMH 880-10 DMH 880-10/880-10 880 10 112 1056 10 134 — — —
DMH 1150-10 DMH 1150-10/1150-10 1150 10 146 — — — — — —
DMH 1500-4 DMH 1500-4/1500-4 1500 4 146 — — — — — —

Pump type 50 Hz 60 Hz 100 Hz

Single pump Double pump

Q* p max.

Max.

stroke

rate

Q* p max.

Max.

stroke

rate

Q* p max.

Max.

stroke

rate

[l/h] [bar] [n/min] [l/h] [bar] [n/min] [l/h] [bar] [n/min]

Note

The pump can be operated in the range between
10 % and 100 % of the maximum dosing capacity.

Pump type [bar]

DMH 251 8
DMH 252 8
DMH 253 5
DMH 254 5
DMH 255 0.8
DMH 257 0.8

Pump type [bar]

DMH 251 2
DMH 252 2
DMH 253 2
DMH 254 2
DMH 255 2
DMH 257 2

Note

A positive pressure difference of at least 2 bar is
required between the suction valve and the
discharge valve in order for the dosing pump to
operate correctly.
If the total counter-pressure (at the dosing point)
and geodetic height difference between the
suction valve and the dosing point is less than
2 bar (20 m WC), a pressure-lo ading valve must
be installed immediately before the dosing point.

10

Maximum counter-pressure*

* Observe the maximum permissible temperatures.

Maximum suction lift* (continuous operation) for media with
a viscosity similar to water

* Applies to a filled dosing head.

Pump type

p max.

[bar]

Single pump Double pump
DMH 251

DMH 2.4-10 DMH 2.4-10/2.4-10 10
DMH 5-10 DMH 5-10/5-10 10
DMH 13-10 DMH 13-10/13-10 10
DMH 19-10 DMH 19-10/19-10 10
DMH 24-10 DMH 24-10/24-10 10
DMH 2.3-16 DMH 2.3-16/2.3-16 16
DMH 4.9-16 DMH 4.9-16/4.9-16 16
DMH 12-16 DMH 12-16/12-16 16
DMH 18-16 DMH 18-16/18-16 16
DMH 23-16 DMH 23-16/23-16 16
DMH 2.2-25 DMH 2.2-25/2.2-25 25
DMH 4.5-25 DMH 4.5-25/4.5-25 25
DMH 11-25 DMH 11-25/11-25 25
DMH 17-25 DMH 17-25/17-25 25
DMH 21-25 DMH 21-25/21-25 25

DMH 252

DMH 11-10 DMH 11-10/11-10 10
DMH 24-10 DMH 24-10/24-10 10
DMH 37-10 DMH 37-10/37-10 10
DMH 46-10 DMH 46-10/46-10 10
DMH 10-16 DMH 10-16/10-16 16
DMH 23-16 DMH 23-16/23-16 16
DMH 36-16 DMH 36-16/36-16 16
DMH 45-16 DMH 45-16/45-16 16
DMH 54-16 DMH 54-16/54-16 16

DMH 253

DMH 21-10 DMH 21-10/21-10 10
DMH 43-10 DMH 43-10/43-10 10
DMH 67-10 DMH 67-10/67-10 10
DMH 83-10 DMH 83-10/83-10 10
DMH 100-10 DMH 100-10/100-10 10

DMH 254

DMH 50-10 DMH 50-10/50-10 10
DMH 102-10 DMH 102-10/102-10 10
DMH 143-10 DMH 143-10/143-10 10
DMH 175-10 DMH 175-10/175-10 10
DMH 213-10 DMH 213-10/213-10 10
DMH 291-10 DMH 291-10/291-10 10
DMH 46-16 DMH 46-16/46-16 16
DMH 97-16 DMH 97-16/97-16 16
DMH 136-16 DMH 136-16/136-16 16
DMH 166-16 DMH 166-16/166-16 16
DMH 202-16 DMH 202-16/202-16 16
DMH 276-16 DMH 276-16/276-16 16

DMH 255

DMH 194-10 DMH 194-10/194-10 10
DMH 270-10 DMH 270-10/270-10 10
DMH 332-10 DMH 332-10/332-10 10
DMH 403-10 DMH 403-10/403-10 10
DMH 550-10 DMH 550-10/550-10 10

DMH 257

DMH 220-10 DMH 220-10/220-10 10
DMH 440-10 DMH 440-10/440-10 10
DMH 575-10 DMH 575-10/575-10 10
DMH 750-4 DMH 750-4/750-4 10
DMH 770-10 DMH 770-10/770-10 10
DMH 880-10 DMH 880-10/880-10 10
DMH 1150-10 DMH 1150-10/1150-10 4
DMH 1500-4 DMH 1500-4/1500-4 4

Pump type

Maximum suction lift

[m WC]
DMH 251 1
DMH 252 1
DMH 253

DMH 21-10 1
DMH 43-10 1
DMH 67-10 1
DMH 83-10 1
DMH 100-10 Flooded suction

DMH 254

DMH 50-10 1
DMH 102-10 1
DMH 143-10 1
DMH 175-10 1
DMH 213-10 1
DMH 291-10 Flooded suction
DMH 46-16 1
DMH 97-16 1
DMH 136-16 1
DMH 166-16 1
DMH 202-16 1
DMH 276-16 Flooded suction

DMH 255 Flooded suction
DMH 257

DMH 220-10 1
DMH 440-10 1
DMH 575-10 1
DMH 770-10 1
DMH 880-10 Flooded suction
DMH 1150-10 Flooded suction
DMH 750-4 Flooded suction
DMH 1500-4 Flooded suction

Pump type

p max.

[bar]

Single pump Double pump

11

Maximum suction lift (continuous operation) for media with
maximum permissible viscosity

6.5 Sound pressure level

* Testing according to DIN 45635-01-KL3.

6.6 Electrical data

6.6.1 Enclosure class

The enclosure class depends on the motor variant selected,
see motor nameplate.

The specified enclosure class can only be ensured if the power
supply cable is connected with the same degree of protection.

Pumps with electronics: The enclosure class is only met if the
sockets are protected! The data regarding the enclosure class
applies to pumps with correctly inserted plugs or screwed-on
caps.

6.6.2 Motor

Version: see motor and pump nameplates.

6.7 AR control unit

Functions of pumps with electronics:

• "Continuous operation" button for function test and dosing
head deaeration

• memory function (stores a maximum of 65,000 pulses)

• two-stage tank-empty signal (e.g. via Grundfos Alldos tank
empty sensor)

• stroke signal/pre-empty signal (adjustable), e.g. as a feedback
to the control room

• dosing controller function (only with sensor – optional)

• diaphragm leakage detection (only with sensor – optional)

• access-code-protected settings

• remote on/off

• Hall sensor

• operating hours counter

• motor monitoring.

Operating modes:

• manual
Stroke frequency: manually adjustable between zero and
maximum

• contact signal control
Multiplier (1:n) and divisor (n:1)

• current signal control 0-20 mA / 4-20 mA
Adjustment of stroke frequency proportional to the current
signal. Weighting of current input.

6.7.1 Inputs and outputs

AR control unit factory settings

• Inputs and outputs: NO (normally open)
or

• inputs and outputs: NC (normally closed).

6.8 Required energy

Power supply for AC voltage

Maximum permissible mains impedance

(0.084 + j 0.084) Ohm (testing according to DIN EN 61000-3-11).
These details apply to 50 Hz.

6.9 Ambient and operating conditions

• Permissible ambient temperature: 0 °C to +40 °C
(for an installation height up to 1000 m above sea level).

• Permissible storage temperature: –20 °C to +50 °C.

• Permissible air humidity: max. relative humidity:
70 % at +40 °C, 90 % at +35 °C.

Pumps with AR control unit only

Maximum permissible mains impedance: 0.084 + j 0.084 Ω
(testing according to EN 61000-3-11).

6.10 Dosing medium

The dosing medium must have the following basic characteristics
for the standard pumps:

• liquid

• non-abrasive
The dosing of abrasive media is possible with certain versions,
on request.

• non-inflammable
The dosing of inflammable media is possible with certain
versions of explosion-proof pumps, in accordance with ATEX.

Pump type

Maximum suction lift

[m WC]

DMH 251 Flooded suction
DMH 252 Flooded suction
DMH 253 Flooded suction
DMH 254 Flooded suction
DMH 255 Flooded suction
DMH 257 Flooded suction

Pump type

DMH 251 55 ± 5 dB(A)*
DMH 252 55 ± 5 dB(A)*
DMH 253 65 ± 5 dB(A)*
DMH 254 65 ± 5 dB(A)*
DMH 255 75 ± 5 dB(A)*
DMH 257 75 ± 5 dB(A)*

Inputs

Contact signal Maximum load: 12 V, 5 mA
Current 0-20 mA Maximum load: 22 Ω
Remote on/off Maximum load: 12 V, 5 mA
Two-stage tank-empty signal Maximum load: 12 V, 5 mA
Dosing controller and diaphragm leakage sensor

Outputs

Current 0-20 mA Maximum load: 350 Ω

Error signal

Maximum ohmic load:
50 VDC / 75 VAC, 0.5 A

Stroke signal Contact time/stroke: 200 ms

Pre-empty signal

Maximum ohmic load:
50 VDC / 75 VAC, 0.5 A

Rated voltage

Permissible deviation from rated

value

230 / 400 V ± 10 %
240 / 415 V ± 10 %
115 V ± 10 %

Caution

The installation site must be under cover!
Do not install outdoors!

Note

In the event of questions regarding the material
resistance and suitability of the pump for specific
dosing media, please contact Grundfos Alldos.

12

Maximum permissible viscosity at operating temperature*

Applies to:

• Newtonian liquids

• non-degassing media

• media without suspended matter

• media with a density similar to water.

* The stated values are approximate values and apply to the

standard pumps.

Permissible media temperature

* For SIP/CIP applications: A temperature of 145 °C at a

counter-pressure of max. 2 bar is permitted for a short period
(15 minutes).

** At 70 °C, the maximum counter-pressure is 9 bar.

7. Transport and storage

7.1 Delivery

The DMH 25x dosing pumps are supplied in different packaging,
depending on pump type and the overall delivery. For transport
and intermediate storage, use the correct packaging to protect
the pump against damage.

7.2 Unpacking

Retain the packaging for future storage or return, or dispose of
the packaging in accordance with local regulations.

7.3 Intermediate storage

• Permissible storage temperature: –20 °C to +50 °C.

• Permissible air humidity: max. relative humidity:
70 % at +40 °C, 90 % at +35 °C.

7.4 Return

The pump must be thoroughly cleaned before it is returned or
stored. It is essential that there are no traces of toxic or
hazardous media remaining on the pump. Drain the oil from the
drive mechanism and package the pump correctly.

Before returning the pump to Grundfos Alldos for service, the
safety declaration at the end of these instructions must be filled
in by authorised personnel and attached to the pump in a visible
position.

If Grundfos Alldos is requested to service the pump, it must be
ensured that the pump is free from substances that can be
injurious to health or toxic. If the pump has been used for such
substances, the pump must be cleaned before it is returned.

If proper cleaning is not possible, all relevant information about
the chemical must be provided.

If the above is not fulfilled, Grundfos Alldos can refuse to accept
the pump for service. Possible costs of returning the pump are
paid by the customer.

The safety declaration can be found at the end of these
instructions.

Note

Note that the viscosity increases with decreasing
temperature!

Pump type

Up to stroke

rate 63
[n/min]

Stroke rate

64-120

[n/min]

From stroke

rate 121

[n/min]

Maximum viscosity* [mPa s ]

DMH 251 300 100 50
DMH 252 300 100 50
DMH 253 300 100 10
DMH 254 300 100 5
DMH 255 200 100 5
DMH 257 200 50 5

Dosing head
material

Min. media

temperature

Max. media temperature

p < 10 bar p < 16 bar

[°C] [°C] [°C]

PVC 0 40 20
Stainless steel,

DIN 1.4571*

–10 100 100

Stainless steel,
DIN 2.4610*

–10 100 100

PP 0 40 20
PVDF** –10 60 20

Warning
Observe the chemical manufacturer's safety

instructions when handling chemicals!

Caution

The dosing medium must be in liquid form!
Observe the freezing and boiling points of the

dosing medium!
The resistance of the parts that come into contact

with the media depends on the media, media
temperature and operating pressure. Ensure that
parts in contact with the media are chemically
resistant to the dosing medium under operating
conditions!

Make sure that the pump is suitable for the actual
dosing medium!

Caution

Do not throw or drop the pump.
Do not use the protective packaging as transport

packaging.

Caution

Grundfos Alldos accepts no liability for damage
caused by incorrect transportation, missing or
unsuitable packaging of the pump, residual
media or leaking oil!

Caution

If a pump has been used for a medium which is
injurious to health or toxic, the pump will be
classified as contaminated.

Caution

The replacement of the power supply cable must
be carried out by an authorised Grundfos Alldos
service workshop.

13

8. Product description and accessories

8.1 General description

The DMH 25x are oscillatory positive-displacement pumps with
hydraulic diaphragm control. The operation procedure of the
dosing pump is shown in the sectional drawing. See fig. 1.

The rotational movement of the drive motor (1p) is converted via
the worm gearing (2p) and eccentric (3p) into the oscillatory
suction and stroke movement of the piston (6p). The piston has
a hollow bore and a row of radial control holes, which provide a
hydraulic connection between the drive area and the piston
stroke area. The sliding plug (5p) envelops the holes during the
stroke and seals the stroke area from the drive area.

The hydraulic excursion of the solid PTFE diaphragm (Q)
displaces an equivalent volume of dosing medium from the
dosing head (2) into the discharge line. With the suction stroke,
the piston creates a low pressure, which propagates in the dosing
head, the ball valve (3b) on the dosing side closes and the dosing
medium flows through the suction valve (3a) into the dosing head.

The stroke volume size is solely determined by the position of the
sliding plug. The active stroke length and corresponding average
dosing flow can therefore be changed continuously and linearly
from 10 % to 100 % using the stroke-length adjustment knob and
Nonius (L).

Fig. 2 DMH 251, 252

Fig. 3 DMH 253

TM03 6448 4506

1p

F

L

ME3b

3a 9p 3p2p5p6p2Q

TM03 6449 4506

1p

F

L

ME3b

3a 9p 3p2p5p6p2Q 4p

14

Fig. 4 DMH 254

Fig. 5 DMH 255

TM03 6450 4506

1p

F

L

M3b

3a 9p 3p2p5p6p2Q 4p

TM03 6451 4506

1p

F

L

M3b

3a 9p 3p2p5p4p2Q 6p

15

Fig. 6 DMH 257

8.1.1 Combined overpressure and degassing valve

The combined overpressure and degassing valve (M) opens if
there is an excessive pressure build-up in the dosing system and
provokes the constant degassing of the hydraulic medium.

8.1.2 Diaphragm protection system AMS

The diaphragm protection system AMS (9p) has a keypad, which
is connected to the dosing diaphragm. The dosing diaphragm
oscillates freely in the dosing head and cannot be overstretched
due to a fault in the dosing system since the diaphragm protection
valve closes if such a fault occurs.

8.1.3 Double-diaphragm system / diaphragm leakage
detection (optional)

General

The piston diaphragm and high-tech dosing pumps with drift-free
diaphragm leakage detection are equipped with the following:

• dosing head with PTFE double-diaphragm system

• ball non-return valve with built-in contact pressure gauge.

Double-diaphragm system

Dosing pumps with a double-diaphragm system with no
diaphragm leakage detection have no pressure gauge. In this
case the ball non-return valve is fitted with a locking unit. The
valve, however, can be retrofitted with a contact pressure gauge.

Ball non-return valve

In order for the diaphragm leakage detection to work and to
protect the diaphragms, the gap must be fully deaerated. Dosing
heads with a double diaphragm are equipped with a ball non­return valve (T) to prevent air from flowing back during the filling
and deaeration process (2u).

Fig. 7 Contact pressure gauge

2) For dosing heads with a double diaphragm with no contact

pressure gauge (no diaphragm leakage detection), a locking
unit is fitted instead of the contact pressure gauge.

TM03 6452 4506

1p

F

L

M3b

3a 9p 3p2p5p6p2Q 7p

Pos. Components

1p Motor
2p Worm gearing
3p Eccentric
4p Recuperating spring (not with drive size 3)
5p Sliding plug
6p Piston
7p Crank

M Combined overpressure and degassing valve
E Degassing valve

9p Diaphragm protection system (AMS)

Q Dosing diaphragm

2 Dosing head
3a Suction valve
3b Discharge valve

L Stroke-length adjustment knob

F Oil-filling screw with dipstick

TM03 6453 4506

Pos. Components

S Contact pressure gauge
T Ball non-return valve
U Connection piece

T

5u

4u

3u

2)

U

5s

3u

2u

S

6s

16

Functional principle of diaphragm leakage detection

The non-return valve and the gap between the diaphragms are
factory-filled with a separating agent (paraffin oil). They are set in
such a way during start-up on the test stand that there is always a
hydraulically separated equilibrium between the valve and
diaphragm gap (the pressure gauge indicates "0" when the pump
is running and when it is stopped).

If one of these diaphragms breaks, the dosing or hydraulic
medium penetrates into the gap between the diaphragms and,
when the ball is removed, into the valve. The system pressure is
therefore impinged on the valve and the contact pressure gauge
is activated. Depending on the design of the system, the
electrically isolated reed contact can trigger an alarm device or
the pump can be switched off.

The contact is triggered at the preset pressure as is shown in the
table below:

Description/use

Set pressure

[bar]

For pumps up to 10 bar
Pressure gauge 0 to 10 bar

1.5

For pumps up to 10 bar
Explosion-proof pressure gauge 0 to 10 bar

1.5

For pumps 16 to 100 bar
Pressure gauge 0 to 100 bar

10

For pumps 16 to 100 bar
Explosion-proof pressure gauge 0 to 100 bar

10

Warning
The contact pressure gauge (Ex) in explosion-

proof version with switch amplifier should be
used if the pump is fitted with an explosion-proof
motor.