GESTRA BW 31A User manual

Return-Temperature Control Valve
BW 31
BW 31A
Original Installation Instructions
819026-01

Contents
Preface................................................................................................................................................3
Availability.............................................................................................................................................3
Text layout ............................................................................................................................................3
Safety..................................................................................................................................................3
Usage for the intended purposeand obvious misuse or abuse...................................................................3
Basic safety notes .................................................................................................................................4
Typographic features of safety notes.......................................................................................................5
Description .........................................................................................................................................5
Scope of supply and equipment specification ..........................................................................................5
Purpose and function.............................................................................................................................8
Storing and transporting the equipment...........................................................................................8
Storing the equipment ...........................................................................................................................8
Transporting the equipment ...................................................................................................................9
Mounting and connecting the equipment.........................................................................................9
Preparing installation .............................................................................................................................9
Connecting the equipment .....................................................................................................................9
Adjusting the closing temperature..................................................................................................10
Adjusting the closing temperature via external setting device .................................................................10
Adjusting the closing temperating without external setting device ...........................................................12
After operation .................................................................................................................................17
Removing external dirt deposits............................................................................................................17
Purging equipment ..............................................................................................................................17
Maintaining equipment ........................................................................................................................19
Servicing equipment ............................................................................................................................19
Troubleshooting ...............................................................................................................................26
Putting equipment out of operation ................................................................................................27
Removing harmful substances..............................................................................................................27
Removing equipment ...........................................................................................................................27
Re-using equipment after storage.........................................................................................................28
Disposing of equipment .......................................................................................................................28
Technical data..................................................................................................................................29
Dimensions and weights ......................................................................................................................29
Pressure & temperature ratings............................................................................................................30
Closing temperatures...........................................................................................................................30
Manufacturer's Declaration.............................................................................................................31

3
Preface
This installation & operating manual will help you
use the return-temperature control valve
KALORIMAT BW 31/BW 31A (referred to as
"equipment" in this document) safely and efficiently
for its intended purpose.
This installation & operating manual is intended for
anyone commissioning, using, operating, servicing,
cleaning or disposing of this equipment and, in
particular, for professional after-sales service
technicians, qualified personnel and authorised and
trained staff.
All of these persons must read and understand the
content of this installation & operating manual.
Following the instructions given in this installation &
operating manual helps avoiding danger and
increases the reliability and service life of the
equipment. Please note that in addition to the
instructions given in this installation & operating
manual you must also observe all locally applicable
rules and regulations concerning the prevention of
accidents as well as approved safety guidelines for
good professional practice.
Availability
Keep this installation & operating manual together
with the plant documentation for future reference.
Make sure that this installation & operating manual
is available to the operator.
The installation & operating manual is part of the
equipment. Please hand over this installation &
operating manual when selling the equipment or
passing it on.
Text layout
Certain text elements of this installation & operating
manual feature a specific typographic design. You
can easily distinguish the following text elements:
Standard text
Cross-reference
Listing
Sub-items in listings
Steps for action.
Here you will find additional useful
information and tips serving to assist you
in using the equipment to its fullest
potential.
Safety
Usage for the intended
purposeand obvious misuse or
abuse
Usage for the intended purpose
The return-temperature control valve KALORIMAT
BW 31/BW 31A, hereinafter called "equipment", is
installed in fluid return lines. It regulates the return
temperature of the fluid as a function of
temperature.
Equipment type BW 31 is only designed for use
with hot water.
Equipment type BW 31A is only designed for
use with hot oil.
Correct use includes compliance with the
instructions given in this installation & operating
manual, in particular obedience to all safety
instructions.
Obvious misuse or abuse
Any other use of the equipment is considered to be
improper.
In particular the use as shut-off valve for the return
line is not permitted.
Note that the equipment is also used incorrectly if
the body material of the equipment is not suitable
for the fluid.

4
Basic safety notes
Risk of severe injuries
The equipment is under pressure and hot during
operation. Before carrying out any work on the
equipment make sure that the following
requirements are met:
The pipes must be depressurized (0 bar).
The fluid must be completely removed from
the pipes and the equipment.
During work on the equipment the
installation must be switched off and
protected against unauthorised or
unintended activation.
The pipes and the equipment must have
cooled down to room temperature (approx.
20 °C).
If the equipment is used in contaminated areas
there is a risk of severe injuries or death caused
by harmful substances in or on the equipment.
Before working on the equipment make sure
that it is completely decontaminated. Always
wear the protective clothing prescribed for
contaminated areas when working on the
equipment.
The equipment must only be used with fluids
that do not attack the body material and the
gaskets and sealings. Otherwise leaks may
occur and hot or toxic fluid could escape.
The equipment and its component parts must
only be mounted or removed by qualified
personnel. A qualified person must be
acquainted with and experienced in the
following:
Making pipe connections.
Working with dangerous (contaminated, hot
or pressurized) fluids.
Risk of minor injuries
Sharp edges on internals present the danger of
cuts to hands. Always wear industrial gloves
when servicing the equipment.
If the support of the equipment during
installation is insufficient the equipment might
fall down, thereby causing bruises or injuries.
Make sure the equipment is safely held in place
during installation and cannot fall down. Wear
protective safety footwear.
Risk of property damage or malfunctions
Malfunctions will occur if the equipment is
installed in a wrong position or with the flow
arrow pointing in the opposite direction of the
fluid flow. This may result in damage to the
equipment or the installation. Make sure that
the flow arrow on the equipment body matches
the indicated direction of the fluid flow in the
pipe.
If the body material is unsuitable for the fluid,
increased wear may occur and fluid may
escape. Before mounting the equipment make
sure that the body material is suitable for the
fluid used in your installation.
Incorrect temperature settings can affect the
proper performance of the installation.
Consequently, parts of the installaton could be
damaged.
Make sure that only qualified and trained
personnel change the closing temperature
setting.
Do not adjust a closing temperature that is
below the factory setting. For more
information on default factory settings see
chapter
“Adjusting the closing temperature“
on page 10.
An inclined installation position can lead to
increased wear on the equipment. Please
contact the manufacturer if the equipment
cannot be installed with the cover pointing
vertically upwards or hanging downwards.

5
Typographic features of safety
notes
Danger note
DANGER
Notes with the heading DANGER warn
against imminent dangerous
situations that
can lead to death or serious injuries.
WARNING
Notes with the heading WARNIN
G warn
against possibly dangerous situations that
could lead to death or serious injuries.
CA
UTION
Notes with the heading CAUTION warn
against dangerous situations that could
lead to minor or moderate injuries.
Information on environmental and property
damage
Attention!
This note warns against situations that
may lead to environmental and/or property
damage.
Description
Scope of supply and equipment
specification
Scope of supply
Our equipment is delivered packed and ready for
assembly.
Equipment specification
The equipment consists of the following main
components:
Body,
Cover and
Regulator.
For the designation of the individual component
parts please refer to the following pages.

6
No.
Designation
1
Nuts (only DN40)
2
Cover
3
Distance sleeve (only DN40)
4
Adjustment nut
5
Bimetallic regulator plates
No.
Designation
6
Thermovit regulator
7
Socket-head bolts
8
Name plate with flow direction arrow
9
Body
10
Gaskets (2 for DN40)
An external setting device is available as optional
extra. This external setting device allows you to
change the closing temperature during operation
without having to remove the cover. There are
different external setting devices depending on the
equipment type.

7
External setting device for BW 31
No.
Designation
11
Star grip knob
12
Temperature scale
13
Forked adjustment piece
External setting device for BW 31A
No.
Designation
13
Forked adjustment piece
14
Adjustment stem
15
Locknut
16
Twin nipple
Equipment with an external setting device
is fitted with a square nut instead of a
n
adjustment nut.
End connections
The equipment is available with the following end
connections:
Butt-weld ends
Butt-weld ends via transition pieces
Socket-weld ends
Flanges
Screwed sockets
Name plate
The following items are indicated on the name
plate:
Type designation
Nominal size
Nominal pressure
Differential pressure
Temperature
Flow arrow
The
name plate is pointed on one side.
This serves as an additional indication of
the flow direction.
In addition, you will find the following indications on
the body or cover:
Material specification
Factory set closing temperature
Application of European Directives
Pressure Equipment Directive
The equipment conforms to this directive (see
"Manufacturer's Declaration" section) and can be
used for the following media:
BW 31
Fluids of group 2
BW 31A
Fluids of group 1
Fluids of group 2

8
ATEX Directive
The equipment does not have its own potential
ignition source and is not subject to this directive
(see "Manufacturer's Declaration" section).
When installed, static electricity may arise between
the equipment and the connected system.
When used in potentially explosive atmospheres,
the plant manufacturer or plant operator is
responsible for discharging or preventing possible
static charge.
If it is possible for medium to escape, e.g. through
actuating mechanisms or leaks in threaded joints,
the plant manufacturer or plant operator must take
this into consideration when dividing the area into
zones.
Purpose and function
Purpose
The equipment regulates and controls distribution
processes in industrial heating systems. As the fluid
temperature falls the equipment increases the fluid
flow in the return line. The fluid will only flow off if
its temperature is below the closing temperature.
Consequently, the flowrate, pressure and
temperature of the fluid are maintained at a fairly
constant level and heat loss is minimized.
The closing temperature is set at our factory. You
can change these default settings within the
adjustable temperature range. For more information
see chapter
“Adjusting the closing temperature“ on
page 10.
Function
The equipment regulates the flow of the fluid by
means of a Thermovit regulator and the force of a
spring.
As the fluid temperature falls the orifice opens.
More fluid can flow through. As the fluid
temperature rises the orifice of the Thermovit
regulator closes. Less fluid can flow through.
The orifice always remains slightly open,thereby
allowing a small flowrate ("bleed flow") to pass
through. The Thermovit regulator is therefore
always surrounded by fluid and can react
instantaneously if the temperature changes.
Storing and transporting the
equipment
Attention!
Equipment can be damaged if stored or
transported improperly.

Close all openings with the sealing
plugs or covers supplied with the
equipment or use similar sealing
covers.

Protect the equipment against
moisture and corrosive atmospheres.

Please contact the manufacturer if the
specified transport and/or storage
requirements cannot be met.
Storing the equipment
Please observe the following items when storing the
equipment:
Do not store the equipment for more than 12
months.
Use the supplied sealing plugs or other suitable
seal caps in order to seal off all openings and
make the equipment watertight.
Protect the sealing surfaces and contact areas
against mechanical damage.
Protect the equipment and all components
against hard shocks and impacts.
Store the equipment only in closed rooms that
meet the following environmental conditions:
Air humidity below 50 %, not condensing
Indoor air: clean, salt-free and non-corrosive
Temperature 5–40 °C.
Make sure that all these requirements are
always met when storing the equipment.
Please contact the manufacturer if you cannot
comply with the recommended storage
conditions.

9
Transporting the equipment
Meet the requirements for storage also when
transporting the equipment.
Prior to transport seal off connections with
sealing plugs.
If you do not have the sealing plugs
supplied wi
th the equipment use
appropriate seal caps to seal off the
connecctions.
For short distances (only a few metres) you can
transport the equipment unpacked.
When transporting the equipment over larger
distances use the original packaging.
If you do not have the original packaging use a
box that protects the equipment adequately
against corrosion and physical damage.
For a short period of time the equipment
may be transported even if the
temperature is below 0
°C, provided that
the equipment is completely empty and
dry.
Mounting and connecting the
equipment
Preparing installation
Take the equipment out of the transport
packaging.
Check the equipment for transport damage.
Contact the manufacturer if you detect any kind
of shipping damage.
When supplied by the factory, the connections are
sealed off with sealing plugs.
Remove sealing plugs before mounting the
equipment.
Keep the sealing plugs for further use.
DANGER
Personnel working on pipes are exposed to
safety risks and may suffer severe injuries,
burns, poisoning or even loss of life.

Make sure that no hot or hazardous
fluid is in the equipment or the pipes.

Make sure that the installation is
switched off and protected against
unautho
rised or unintended activation.

Make sure that the equipment and the
pipes have cooled down to room
temperatures.
Drain pipes until they are empty.
Switch the installation off and protect it against
unauthorised or unintended re-activation.
Connecting the equipment
DANGER
Incorrectly connected equipment can
cause fatal accidents or severe injurie
s.

Make sure that only qualified skilled
personnel connect the equipment to
pipes.

Make sure that the flow arrow on the
equipment body matches the direction
of flow in the pipe.
Specialist personnel must be highly qualified and
fully experienced in making pipe connections for the
respective type of end connection.

10
Attention!
Equipment will b
e damaged if the end
connections are undersized.

Make sure that the connections are
strong and rigid enough to support the
weight of the equipment and to
withstand the forces that occur during
operation.
The equipment should be fitted in a horizontal
pipe with the cover in a vertical position.
In exceptional cases the equipment can
also be instal
led with the cover in an
inclined plane.
Attention!
An inclined installation position of
the
cover can affect the performance of the
equipment and increase wear on the
Thermovit regulator.

Please contact the manufacturer if an
installation with the cover in a vertical
position is not possible in your plant.
Mount the equipment in the desired installation
position.
Make sure that the equipment is safely mounted
and that all connections are made correctly.
To remove residues from the pipes and the
equipment after installation purge the
pipes with the fluid to be used. For more
information see chapter
"Purging
equipment"
on page 17.
Adjusting the closing temperature
When delivered, the equipment features a factory-
set closing temperature in accordance with the
design data.
Attention!
Risk of malfunctions or damage due to
incorrect setting of Thermovit regulator.

Make sure that only qualified
personnel change the closing
temperature setting.

Do not adjust a closing temperature
that is below the factory-set closing
temperature.
Note that closing temperatures below the factory
setting may damage the Thermovit regulator.
If you want to set a lower closing temperature
you have to use different equipment.
To re
-set the factory setting of the closing
temperature use the
set value indicated in
the table in chapter "Adjusting the closing
temperating without external setting
device"
.
Adjusting the closing temperature
via external setting device
The external setting device enables you to change
the closing temperature without having to remove
the cover.
You can therefore change the closing temperature
setting also during operation.
The are different procedures for BW 31 and
BW 31A.
Adjusting the closing temperature for BW 31
Use the star grip knob of the external setting device
to adjust the desired set value. The current closing
temperature is indicated by the scale. When the
equipment is delivered the closing temperature is
set to the lowest value.

11
Attention!
Risk of malfunctions or damage due to
incorrect setting of Thermovit regulator.

Make sure that only qualified
personnel change the closing
temperature setting.

Do not adjust a closing temperature
that is below the factory-set closing
temperature.
To lower the closing temperature turn the star
grip knob clockwise.
To raise the closing temperature turn the star
grip knob anticlockwise.
To check the setting measure the return
temperature of the fluid downstream of the
equipment.
Repeat the setting procedure if the return
temperature does not meet the set value.
Adjusting the closing temperature for BW 31A
The closing temperature is set via the slide lift.
When the equipment is delivered, the following
temperature settings as a function of nominal size
are possible:
Factory setting for BW 31A with external
setting device
Nominal
size
Closing
temperature
[°C]
Set value X
[mm]
Lift
Y
[mm]
DN15
90
27.0
4.6
DN20, DN25
70
27.6
4.0
DN40
70
48.4
6.6
These factory settings are calculated for ambient
temperatures of 18 – 21 °C.
To change the settings proceed as follows:
WARNING
Injuries such as burns or poisoning may
occur if fluid escapes through the external
setting device.

Make sure that the twin nipple of the
external setting device is fixed and
cannot work loose.
Use an open-end spanner (US: wrench) to
secure the twin nipple (16) against inadvertent
misadjustment.
To loosen the locknut (15) turn it anticlockwise.
To raise the closing temperature turn the
adjustment stem (14) anticlockwise.
Attention!
Risk of malfunctions or damage due to
incorrect setting of Thermovit regulator.

Make sure that only qualified
personnel change the closing
temperature setting.

Do not adjust a closing temperature
that is below the factory-set closing
temperature.

12
To lower the closing temperature turn the
adjustment stem (14) clockwise.
The following table indicates the closing
temperature that will be set by giving the
adjustment stem a certain number of full turns.
Note that the indicated values are based on the
factory setting.
Number of
turns
DN15
DN20
DN25
DN40
1
104
83
80
2
120
95
90
3
137
109
102
4
156
123
116
5
180
137
136
6
210
158
165
7
260
180
196
8
–
210
237
9
–
255
–
To set the max. closing temperature of 280 °C turn
the adjustment stem as often as indicated in the
following table.
Nominal size
Number of full turns
DN15
7.2
DN20, DN25
9.4
DN40
8.7
Attention!
Incorrect setting if the adjustment stem is
turned inadvertendly when tightening the
locknut.

Use a screwdriver to secure the
adjustment stem against turning when
tightening the locknut.
To secure the adjustment stem (14) against
turning fasten locknut (15) hand-tight, while
securing the adjustment stem with a
screwdriver.
To check the setting measure the return
temperature of the fluid downstream of the
equipment.
Repeat the setting procedure if the return
temperature does not meet the set value.
Adjusting the closing temperating
without external setting device
Remove cover to change the closing temperature
without using the external setting device. When
delivered, the equipment features the closing
temperature setting specified in the order.
There is a set value for each closing temperature.
The set value X is measured between the upper and
the lower spring plate.
Equipment of size DN 15 does not have a
lower spring plate. With this equipment
you have to measure the set value
between the upper spring plate and the top
edge of the h
exagon part.

13
DANGER
Personnel working on pipes are exposed to
safety risks and may suffer severe injuries,
burns, poisoning or even loss of life.

Make sure that no hot or hazardous
fluid is in the equipment or the pipes.

Make sure that the installation is
switched off and protected against
unauthorised or unintended activation.

Make sure that the
equipment and the
pipes have cooled down to room
temperatures.
Remove the cover as described on page 18.
Attention!
Risk of malfunctions or damage due to
incorrect setting of Thermovit regulator.

Make sure that only qualified
personnel change the closing
temperature setting.

Do not adjust a closing temperature
that is below the factory-set closing
temperature.
Ascertaining set value
The set value depends on the type of equipment
and the desired closing temperature.
Refer to the following tables for the required set
value.
Ascertaining the set value for BW 31
The number of plate pairs used in the Thermovit
regulator depends on the required closing
temperature.
Closing temperature
Number of plate pairs
DN15
20–140 °C
7
145–160 °C
6
DN20, DN25
20–115 °C
9
120–160 °C
8
DN40
20–130 °C
7
135–160 °C
6
Attention!
Risk of malfunctions or dam
age due to
incorrect setting of Thermovit regulator.
Only the correct number of plate pairs
ensures that the set value yields the
correct closing temperature.

Before adjusting the set value make
sure that the correct number of plate
pairs is used.

If necessary mount a Thermovit
regulator with the correct number of
plate pairs.

14
Closing temperature
[°C]
Set value [mm]
DN15
DN20,
DN25
DN40
20
22.4
23.6
41.8
25
22.8
24.2
42.7
30
23.2
24.8
43.6
35
23.6
25.3
44.4
40
24.0
25.8
45.2
45
24.4
26.4
46.0
50
24.8
26.9
46.8
55
25.2
27.4
47.6
60
25.6
28.0
48.5
65
26.0
28.5
49.3
70
26.4
29.0
50.1
75
26.7
29.5
50.9
80
27.1
30.1
51.7
85
27.5
30.7
52.4
90
27.9
31.3
53.0
95
28.3
31.8
53.5
100
28.7
32.3
54.0
105
29.0
32.8
54.4
110
29.4
33.3
54.8
115
29.8
33.8
55.1
120
30.2
32.7
55.5
125
30.6
33.0
55.8
130
30.9
33.3
56.2
135
31.2
33.6
54.5
140
31.5
34.0
54.8
145
30.4
34.3
55.0
150
30.7
34.6
55.3
155
31.0
34.9
55.5
160
31.2
35.1
55.7
The set value is based on ambient temperatures of
18 – 21 °C. If the ambient temperature is higher or
lower use the following table to adjust the set value.
Ambient temperature
[°C]
Correction value [mm]
DN15
DN20,
DN25
DN40
9–12
+0.75
+0.9
+1.5
12–15
+0.5
+0.6
+1.0
15–18
+0.25
+0.3
+0.5
18–21
0
21–24
–0.25
–0,3
–0.5
24–27
–0.5
–0.6
–1.0
27–30
–0.75
–0.9
–1.5
Please contact the manufactur
er if the
ambient temperature passes outside the
indicated temperature range.

15
Ascertaining the set value for BW 31A
Closing temperature
[°C]
Set value [mm]
DN15
DN20,
DN25
DN40
20
22.4
23.6
41.8
30
23.0
24.4
43.1
40
23.6
25.2
44.4
50
24.3
26.0
45.7
60
25.0
26.8
47.1
70
25.7
27.6
48.4
80
26.4
28.4
49.7
90
27.0
29.2
50.9
100
27.7
30.0
52.0
110
28.4
30.7
52.9
120
29.0
31.4
53.6
130
29.6
32.1
54.2
140
30.2
32.7
54.8
150
30.7
33.2
55.3
160
31.2
33.7
55.7
170
31.6
34.2
56.1
180
32.0
34.6
56.5
190
32.4
35.0
56.9
200
32.7
35.3
57.3
210
33.0
35.6
57.6
220
33.2
35.8
57.9
230
33.4
36.1
58.2
240
33.6
36.3
58.5
250
33.8
36.5
58.7
260
34.0
36.7
59.0
270
34.1
36.9
59.2
280
34.2
37.0
59.3
The set value is based on ambient temperatures of
18 – 21 °C. If the ambient temperature is higher or
lower use the following table to adjust the set value.
Ambient temperature
[°C]
Correction value [mm]
DN15
DN20,
DN25
DN40
9–12
+0.6
+0.75
+1.2
12–15
+0.4
+0.5
+0.8
15–18
+0.2
+0.25
+0.4
18–21
0
21–24
–0.2
–0.25
–0.4
24–27
–0.4
–0.5
–0.8
27–30
–0.6
–0.75
–1.2
Changing set value
Attention!
Risk of malfunctions or damage due to
incorrect setting of Thermovit regulator.
Only the correct number of plate pairs
ensures that the set value yields the
correct closing temperature.

Before adjusting the set value make
sure that the correct number of plate
pairs is used.

If necessary mount a Thermovit
regulator with the correct number of
plate pairs.

16
Use the Thermag nut (4) to adjust the desired set
value.
The Thermag nut used in equipment DN 15 to DN
25 is a nut type M6 and in equipment DN 40 a nut
M8. It is locked and sealed with Loctite 222.
To reduce the set value fasten the Thermag nut.
The closing temperature is reduced.
To increase the set value loosen the adjustment
nut.
The closing temperature is increased.
Use Loctite 222 to lock and seal the Thermag
nut against inadvertent misadjustment.
Attach cover to the equipment as described on
page 18.
To check the setting measure the return
temperature of the fluid downstream of the
equipment.
Repeat the setting procedure if the return
temperature does not meet the set value.

17
After operation
DANGER
If the equipment is used in contamin
ated
areas there is a risk of severe injuries or
death caused by harmful substances in or
on the equipment.

Only qualified personnel are allowed to
perform work on contaminated
equipment.

Always wear the protective clothing
prescribed for contaminated areas
when working on the equipment.

Make sure that the equipment is
completely decontaminated before
carrying out any service work.

Follow the pertinent instructions for
handling the hazardous substances in
question.
Removing external dirt deposits
Use fresh water and a cloth to remove dirt and
contaminants from the equipment body.
Purging equipment
Rinse the equipment in order to remove any dirt
particles or fluid residues inside the equipment.
When fixing the cover onto the equipment
body the gasket will be compressed. As a
result the gasket can no longer seal
properly if the cover is taken off again. It is
therefore essential that you always insert a
new gasket whenever you remove and re
-
attach the cover.
Attention!
Malfunctions due to dirt deposits on
Thermovit regulator.

Remove Thermovit regulator before
rinsing the equipment.
To remove the Thermovit regulator proceed as
follows:
DANGER
Personnel working on pipes are exposed to
safety risks and may suffer severe injuries,
burns, poisoning or even loss of life.

Make sure that no hot or hazardous
fluid is in the equipment or the pipes.

Make sure that the installation is
switched off and protected against
unauthorised or unintended activation.

Make sure that the equipment and the
pipes have cooled down to room
temperatures.

18
Removing cover
The cover of equipment DN 15 to DN 25 is fixed in
place by means of four 8 mm socket-head cap
screws. The cover of equipment DN 40 is fixed in
place by means of four hexagon-head bolts M13
and nuts.
Slacken the four cover screws or bolts.
Take the four nuts off the equipment (DN 40).
Lift the cover off the body.
Removing Thermovit regulator
The Thermovit regulator is screwed to the body via
a hexagon piece A. F. 24 mm (DN 40: A. F. 36
mm).
Unscrew the Thermovit regulator off the body at
the hexagon piece.
Mounting cover
Attention!
Equipment may leak if the gasket is
damaged.

It is therefore essential that you
always insert a new gasket before re-
attaching the cover.

Make sure that the cover is not tilted
or skewed when refitted.
Fix cover to equipment body.
Fasten screws / nuts and bolts with the
following tightening torque:
DN15 to DN25: 35 Nm
DN40: 45 Nm
Purging pipes
Attention!
Equipment may be damaged by unsuitable
cleaning fluid.

Rinse the pipe with the same fluid that
is used during normal operation.

Make sure that the cleaning fluid does
not come into contact with the fluid
used during normal operation.

Make sure that the cleaning fluid does
not damage the equipment material if
you use a different fluid for cleaning
than the normal operating fluid.
Switch on the installation and rinse the pipes.
Check connections for leaks.
After rinsing keep the installation switched on
until the pipes are completely empty.
Switch the installation off and protect it against
unauthorised or unintended re-activation.

19
Mounting Thermovit regulator after purging
Remove the cover as described on page 18.
Attention!
Malfunctions due to inadvertent
misadjustment of Thermovit regulator.

Make sure that the setting of the
Thermovit regulator is not changed
when mounting or servicing the
equipment.
Fasten the Thermovit regulator with the
following tightening torque:
DN15 to DN25: 90 Nm
DN40: 140 Nm.
Attach cover to the equipment as described on
page 18.
Maintaining equipment
The equipment is maintenance-free.
Servicing equipment
You may exchange the following component parts
in case of wear or damage:
Thermovit regulator
Gasket between cover and body
External setting device (if provided)
Gasket for external setting device (if provided)

20
Spare parts for BW31 without external setting device
No.
Designation
DN
Temperature
range
[°C]
Qty.
Stock code #
6 Thermovit regulator, complete 15
20–90
1
184726
60–130
1
031884
20, 25
20–90
1
184560
40–115
1
004339
40
20–65
1
184544
50–110
1
004342
10
Gasket
15, 20, 25
20*
560493
40
20**
375699
* one piece required
** two pieces required