Danfoss AQ356845617175 Gasketed And Semi Welded Plate Heat Exchangers Instruction Manual
- June 13, 2024
- Danfoss
Table of Contents
- Danfoss AQ356845617175 Gasketed And Semi Welded Plate Heat Exchangers
- Product Information
- Product Usage Instructions
- Introduction
- Safety alert notices
- Identification of the heat exchanger
- Design/components
- Accessories/optional components
- Function
- Installation
- Operation
- Maintenance
- Troubleshooting
- After sales service
- References
- Read User Manual Online (PDF format)
- Download This Manual (PDF format)
Danfoss AQ356845617175 Gasketed And Semi Welded Plate Heat Exchangers
Product Information
The product is a plate heat exchanger manufactured by Danfoss. It is available in gasket and semi-welded versions. The heat exchanger is designed for various applications and is suitable for single plate and semi-welded plate type heat exchangers.
Safety Alert Notices:
- Always comply with local regulations and legislation when handling the plate heat exchanger.
- Only qualified personnel should handle the heat exchanger during lifting, transportation, installation, commissioning, and maintenance.
- Observe warning symbols and safety notices to prevent accidents.
Identification of the Heat Exchanger:
The heat exchanger is equipped with a nameplate located on the front (head)
of the unit. Additional nameplates may be present if specified and ordered by
the client. The nameplate provides important technical details of the heat
exchanger.
Key information on the nameplate includes:
- Month/year of production
- Certification/approval type (e.g., CE, NoBo, ASME, DNV-GL)
- HEX ID – Calculation number
- Tag number – assigned to identify a project or equipment
- Type designation
- Serial number
- Assembly (A) measure nominal (min./max.)
- Minimum/maximum design temperature
- Maximum differential pressure
- Inlet-outlet connections
- Design pressure
- Test pressure
- Total internal volume
- Fluid type per side
It is essential to ensure that the intended process is compliant with the nameplate data before installation. Never exceed any of the stated values on the nameplate. Do not make changes to the nameplate or repaint it. Avoid using aggressive cleaning detergents when cleaning the heat exchanger if a foil sticker/label is used. The nameplate should not be removed. For single plate heat exchangers (Metal/Stainless steel) with types S-, SF-, SW- (except industrial refrigeration), SWC-, and SEC-, the nameplate also includes information such as month/year of production, certification/approval type, HEX ID, tag number, unit number, plate heat exchanger type, and A-measure nominal (min./max.).
Example nameplate:
- MADE IN DENMARK
- HEX ID: 32-220510115016
- Tag no.: Unit no. 1
- Plate heat exchanger type: S86-IS16
- Month and year: 09-2022
- Serial no.: DKA11322350001
- A-measure nom. (min./max.): 744.2 (725.7 / 762.6)
- Certification/Approval type: 1727
- Min./Max. design temperature: 15.0 / 100.0°C
- Max. differential pressure: Inlet > Outlet
- Design pressure: 15.0 bar
Product Usage Instructions
- Ensure compliance with local regulations and legislation when handling the plate heat exchanger.
- Only qualified personnel should handle the heat exchanger during lifting, transportation, installation, commissioning, and maintenance.
- Refer to the nameplate for important technical details of the heat exchanger.
- Before installation, verify that the intended process is compliant with the nameplate data.
- Never exceed any of the stated values on the nameplate.
- Do not make changes to the nameplate or repaint it.
- Avoid using aggressive cleaning detergents if a foil sticker/label is used.
- Do not remove the nameplate.
For single plate heat exchangers (Metal/Stainless steel) with types S-, SF-, SW- (except industrial refrigeration), SWC-, and SEC-, follow the additional instructions provided on the nameplate.
Introduction
This installation manual is a guide for installation, commissioning, operation, and maintenance of gasketed and semi-welded plate heat exchangers manufactured and supplied by Danfoss. It is meant for those who are responsible for the installation, operation, and maintenance of the heat exchangers. It is recommended that you read this manual carefully before commencing any work with the heat exchanger. This installation manual is applicable for gasketed, and semi-welded plate heat exchangers manufactured and supplied by Danfoss. Danfoss cannot be held responsible or liable for damage because of incorrect installation, use and/or maintenance of Danfoss gasketed and semi-welded heat exchangers or damage caused by as not complying with the instructions in this installation manual. Please note that our plate type heat exchangers are specially designed and built for the optimal design conditions (pressures, temperatures, capacities, type of fluids etc.) provided by the customer during the calculation process – as stated on the nameplate. Sudden pressure peaks or pressure surges which can occur during start-up or shutdown of the system can severely damage the heat exchanger and should be prevented. Danfoss cannot be held responsible for any damage because of any operation deviating from the original design criteria.
- Drawings and figures featured in this document serves as examples and for illustrative purposes only
- Always comply to local regulations and legislation when handling the plate heat exchanger.
- Only qualified personnel should handle the heat exchanger during lifting, transportation, installation, commissioning, and maintenance.
Safety alert notices
The following must always be observed when installing or servicing plate heat exchangers:
- Comply with national/local safety regulations
- Ensure that the heat exchanger is free from pressure and completely drained and flushed with clean water where possible.
- Ensure that the heat exchanger is cooled down to ambient temperature between 10 – 40 °C (50 – 104 °F)
Warning symbols refer to safety alert notices. Warning/safety notices should
be observed carefully to prevent:
Personal injury caused by:
- Wrong transport/lifting
- Burning/freezing because of touching parts with extreme temperatures.
- Burning/freezing/poisoning because of uncontrolled release of pressurized media
- Contact with chemicals
- Touching sharp edges of e.g., plates or cassettes
- Draining or overflowing tanks
Equipment damage caused by:
- Wrong transport/lifting
- Liquid hammering
- External forces
- Corrosion
- Chemical reaction
- Erosion
- Material fatigue
- Thermal and/or mechanical shock
- Freezing
- Blocking of the heat exchanger due to particles
- Operation outside the design criteria
Identification of the heat exchanger
Nameplate
All plate heat exchangers supplied by Danfoss are provided with a name plate
positioned on the front (head) of the heat exchanger. Additional nameplates
can be found elsewhere if specified by the client and ordered as an option. On
the name plate main technical details of the heat exchanger are specified.
Before installation, please make sure that the intended process is compliant
with the name plate data.
- Please note that other nameplates than shown in this operation manual (e.g., customized nameplates, SONDEX® nameplates as well as Danfoss nameplates) may occur.
- Never exceed any of the stated values on the nameplate, at any time!
- Do not make changes to the nameplate or repaint it, at any time.
- Avoid aggressive cleaning detergents for cleaning the heat exchanger when a foil sticker/label is used.
- Do not remove the nameplate.
Technical documentation – data sheets and drawings
Each heat exchanger comes with a data sheet and a dimension drawing unless
other is specified as per customer order.
Please note that other data sheets and drawings than shown in the following
examples may occur.
Example of a data sheet for a gasketed heat exchanger:
Danfoss HEXSelector 1.0.17
Customer | A | Date | 6.10.2021 |
---|---|---|---|
Project | Montes del Plata 3039 – HU Cooler Improv | Engineer | Heikki |
Saaros
HEX Type| S44A-IG16-80-TLA| Contact Person
E- mail
Units Connected| 1 (Parallel)|
Calculated Parameters Unit| Side 1| | Side 2
---|---|---|---
Flow Type| | CounterCurrent
Heat Load kW| | 100,37
Inlet Temperature °C| 59,4| | 31,0
Outlet Temperature °C| 35,0| | 39,7
Mass Flow Rate kg/s| 2,12| | 2,76
Volumetric Flow Rate L/min| 145,00| | 166,67
Total Pressure Drop kPa| 82,11| | 13,80
Pressure Drop in Port kPa| 0,29| | 0,39
Surface Margin %| | 2,58
LMTD K| | 9,8
HTC (Available/Required) W/m²·K| | 319 / 311
Port Velocity m/s| 0,73| | 0,84
Shear Stress Pa| 62,83| | 10,30
Properties of Fluid| Unit| Side 1| Side 2
---|---|---|---
Fluid| | Oil ISO VG 150| Water
Liquid Viscosity| mPa·s| 86,9600| 0,7181
Liquid Density| kg/m³| 879,0000| 994,6086
Liquid Heat Capacity| kJ/kg.K| 1,9380| 4,1758
Liquid Thermal Conductivity| W/m·K| 0,1346| 0,6206
Specifications| | Unit| Side 1| Side 2
---|---|---|---|---
HEX Type| | | S44A-IG16-80-TLA
Number of Plates| | | 80
Grouping| | | 1×40 + 0x0 / 1×39 + 0x0
Plate Thickness| | mm| 0,4
Plate Material| | | AISI316L
Effective Area| | m²| 32,84
Gasket Material| | | NBRH (HangOn)
Frame| Type Length
Maximum Number of Plates
| mm| IG 639 99
Volume| | l| 60,0| 58,5
Weight, empty/operating| | kg| 499 / 610
Paint Category| | | Category C2L
Paint Color| | | BLUE RAL 5010
Connection| Inlet
Outlet
| | F1: DN 65 Flange rubberlind HT PN10/PN16
F4: DN 65 Flange rubberlind HT
PN10/PN16
| F3: DN 65 Flange rubberlind HT
PN10/PN16
F2: DN 65 Flange rubberlind HT
PN10/PN16
Certification/Approval Type| | | PED 2014/68/EU, Art. 4.3
Minimum Design Temperature °C
0,0
Maximum Design Temperature °C
90,0
Maximum Differential Pressure __ bar
16,0
Maximum Test Pressure| | bar| 20,0
Maximum Design Pressure| | bar| 16,0| 16,0
Type designation for a gasketed heat exchanger (Stated on the data sheet)
Design/components
-
Frame
The heat exchanger frame consists of a frame plate (head), a pressure plate (follower), a carrying bar, a guiding bar, and a column. The tie rods are used to press the plate pack together. The size and number of tie rods depend on the type of heat exchanger and the pressure rating. The (ring) gasket material is carefully selected to match the combination of temperature and chemical resistance requirements (e.g., NH₃ and compressor oil on the welded side).
Single Plates
Single plate pack consists of single plates fitted with a flow gasket on each plate to seal the plate pack. The number of plates, size and other criteria depend on the thermal output required. The number of plates determines the total heat transfer area (surface). -
Semi-welded plates (plate cassettes)
A plate cassette consists of two single flow plates welded together, creating a sealed flow channel. The cassettes are fitted with two individual gaskets, a ring gasket, and a flow gasket, to seal the plate pack preventing the intermixing of media. This gasket design allows the use of different gasket materials for the ring and flow gaskets respectively for best fit to the actual media and temperature conditions. -
Gaskets
The following gasket types are used in Danfoss plate heat exchangers:- SonderLock gaskets
- Hang-on gaskets (type A, B, AD, AE, A2 and B2)
- D-LockTM gaskets
- Glued gaskets for sanitary plate heat exchangers (Recommended glue/adhesive that is FDA compliant – DOWSIL™ 786 Silicone Sealant-M Clear, for non food application you can use 3M 1099)
-
Right (R)/ Left (L) plates
Most of the plates are designed in such a way that they can be used both as right and left plates, by alternately turning them 180°. Semi-welded cassettes are not turned. On a right plate the media flows from porthole F2 to F3 or reverse from porthole F3 to F2. On a left plate the media flows from porthole F1 to F4 or reverse from porthole F4 to F1.
Accessories/optional components
Insulation jackets/covers
We offer insulation jackets for our range of plate heat exchangers. For heat
insulation, we use mineral wool, and for applications with condensation risk
on external surfaces of heat exchanger we offer closed cell PU foam.
Drip/condensation tray
A drip/condensation tray collects any remaining water after drainage (when the
unit has been opened for inspection and maintenance), as well as the water
that has condensed on the outside of the heat exchanger during operation. We
offer two types of drip/condensation trays, either insulated or uninsulated.
Both types come with a 0,8 mm electro galvanized sheet metal. The insulated
version comes with a 60 mm of PU-foam insulation inside the drip/condensation
tray. The insulated drip/condensation tray is equipped with holes (and
reinforcements) for connecting, with the foot units of the plate heat
exchanger. Depending on the length of the heat exchanger it is placed inside
the drip/condensation tray and only the column is located outside the
drip/condensation tray, or it is hanging underneath the heat exchanger.
Note: place the insulated drip tray before lifting the plate heat
exchangers in place.
Safety cover
If the plate heat exchanger is being used with temperatures above 45°C or with
aggressive fluids, we advise that you cover the plate heat exchanger with a
screen plate to prevent the risk of human exposure to the surface and fluids.
Inline filter/filtration
If the fluid in the plate heat exchanger contains particles larger than the
free channel between the plates, it is recommended to fit an inline filter.
The inline filter is placed in the portholes in the plate pack (inserted from
the follower side) on the inlet connections of the heat exchanger. The inline
filter offers a last line of defence in case of faliure in the main filter
system or if foreign objects are introduced into the pipe system during
maintenance. The filters are supplied in custom length, to suit the total
length of the plate pack, and supplied in AISI316L or Titanium.
Instrumentation (for marine applications)
We offer inline instrumentation flanges fully fitted with:
- Thermometer
- A 1/ valve used as drainage valve or air bleed valve, depending on orientation
- Pressure gauge
Sectioning
In some applications it can be useful to add intermediate frames with special
flow diverting corner pieces/blocks. Using these, it is possible to combine
several plate heat exchangers into one, e.g., pasteurizers in the dairy
industry. Intermediate frames are only available for IS and FS frames.
Connections
Depending on the heat exchanger application, various connection types are
available e.g.,
- Standard flange, threaded holes on head
- Stud bolts on head
- Flange welded on pipe
- Threaded connection
- Dairy type connections: SMS, RJT, DS, DIN
- Elbow flange
Standard flange
The standard flange connection is the most used option for DN50 and bigger.
The head has threaded holes suitable for DIN or ANSI flanges, depending on the
requirements. The port holes can be uncladded (porthole only covered by
paint), cladded (AISI304/316/Titanium or Hastelloy), assembled with a gasket,
or be equipped with a rubber liner which also acts as a gasket.
Stud bolts on head
The head can also be supplied with stud bolts fitted or shipped as loose parts
.
Threaded connection
Threaded connections are available up to DN50/2”
Welded-on pipe
Flanges are welded onto pipe and head respectively (flange elbows are also
possible).
Dairy connection
For dairy applications and other food applications with strict hygiene
demands, a selection of different types of dairy type clamps/stainless steel
welded connectors are available.
Elbow flange
If the heat exchanger has multiple passes (please refer to the multi-pass
solution section), it will have 1-4 flange connections on both head and
follower. This makes servicing a little more complicated, as the heat
exchanger is locked between two sets of pipes. To counter this, we suggest the
use of flange type elbows, as the needed pipe dismantling can be reduced to a
minimum in this manner. Elbow connections should be designed in a way, that
their removal will allow follower frame plate to slide across carrying bar
(when plate pack is loosened for service needs) without obstacles.
Function
Single-pass solution
Single-pass heat exchangers (gasketed and Semi-welded units) allow the two
fluids to pass each other only once, a single-pass heat exchanger has all
connections on the head. Single-pass solutions are available with co-current
or counter-current flow depending on the specified duty.
With all connections on the head, maintenance and cleaning of single-pass solutions is much easier, as opening the plate heat exchangers do not interfere with the pipe installation.
Multi-pass solution
Multi-pass heat exchangers allow the fluid to pass through the heat exchanger
several times before exiting. The main purpose it to change the flow direction
of one or both fluids and this is done by using combi-plates (e.g., plates
with 1, 2 or 3 un-holed ports). A multi-pass solution has connections on the
head and the follower.
Multi-section solution
Multi-section plates heat exchangers can be used for heating and cooling of
two or more medias. A multi-section solution can be considered as multiple
(two or more) heat exchangers in one frame. The multi-section heat exchanger
is delivered with intermediate frames with corner blocks dividing the plate
heat exchanger into various sections where e.g., pre -heat ing, pasteurization
and cooling can take place all at once Intermediate frames are only available
for IS and FS frames.
Installation
Before installation
Prior to installation, check if the assembly measure (A measure) is in
accordance with the name plate as the tie rods may have loosened during
transportation. If the assembly measure does not comply to the nameplate the
heat exchanger must be tightened, follow the “Closing the heat exchanger”
section.
Foundation
Install the plate heat exchanger on a flat foundation providing enough support
for the frame and sufficient space for service and maintenance.
All mount brackets as well as bottom of the header should be fully supported
by foundation or support frame. Foundations and support frame should be able
to carry load of heat exchanger when it is full of working medias (see fig. 17
).
Space requirement
Ensure enough space around and above the plate heat exchanger for maintenance
purposes (e.g., replacement of plates and/or gaskets, tightening of the plate
pack etc.) as well as the lifting equipment to be used. As a rule of thumb,
free space around the unit should be 1.5 x Width (where “W” equals the width
of the header) on each side of the unit. Free height above the unit should be
0,5 x Height (where “H” equals the height incl. the roller of the unit), see
fig. 18. Place the insulated drip/condensation tray before putting the plate
heat exchangers in installation place.
Short-term storage rules (less than 1 month) Make sure heat exchanger is emptied/dried and has no (or achievable minimum) leftovers of working media inside. Always avoid, storing the heat exchanger in areas with high ozone content (example around brushed electric motors or welding equipment), salt air and other corrosive atmospheres. All connections must be closed to prevent water or mechanical particles/debris to enter the heat exchanger. Factory provided cover plugs can be used for that purpose. To prevent damage to the gaskets, do not store organic solvents or acids near by the heat exchanger and avoid direct sunlight, intensive heat radiation or ultraviolet radiation. Preferably the plate heat exchanger should be stored inside in dry conditions at room temperatures round 15 – 20 °C (59 – 68 °F) and a humidity of max. 70%. Minimum and maximum storage temperatures should be inside of design range of heat exchanger (see the product label). All connections should be covered to prevent any dirt or water to enter the plate heat exchanger. The tie rods should be well coated with a suitable grease or similar lubricant. Loosen the tie rods to supply air flow to the heat exchanger, so that any moisture does not damage the equipment and to extend the lifetime of the gaskets, as the rubber material may lose its elastic property when it is subjected to pressure for more than 6 months.
Long-term storage rules (more than 1 month) Apply rules of short-term storage,
plus:
To extend gasket service lifetime, it is recommended to relax the gaskets by
loosening the tie rods by approximately 10% of the compressed plate pack
dimensions. Grease all tightening rods with thin layer of grease. Place the
plate heat exchanger in a protective box provided with a lining on the inside
that will prevent against moisture penetration. The protective box should
protect heat exchanger from atmospheric effects (rain, snow, strong wind) and
mechanical damages. Examine packing condition at least once a month.
For certain applications it’s good practice to fill the HEX with e.g., nitrogen gas during transportation (max. 1 bar)
Before raising / lifting – warnings
The plate heat exchanger may fall or be damaged if the raising and lifting
instructions are not followed or if improperly lifting equipment or procedures
are used.
- CAUTION: Only use lifting equipment that is approved for the weight of the heat exchanger and is in full compliance with the specification and limitation of the equipment. The weight of the heat exchanger can be found on the datasheet.
- CAUTION: Never use steel cables/ropes, chains, hooks, or damaged lifting slings when lifting the plate heat exchanger.
- Always have authorized personnel to lift and move the plate heat exchangers and always observe the correct procedures when lifting and/or moving the equipment.
- Never lift the heat exchanger using any other method than described and never use the connections, studs, tie rods, the column, or intermediate frames (if fitted) for lifting.
Raising the unit from a lying position
The following description applies to all SONDEX® and Danfoss frame types (ST,
IG, DG, FG, IS, DS) with a length up to 2500 mm. These units are usually
delivered lying with the head/fixed cover facing down on a pallet. Depending
on the type of connection mounted on the heat exchanger, the unit may be
delivered in an upright position instead.
How to raise the unit:
- Remove all tightening elements from the plate heat exchanger and the pallet
- Place lifting slings under the head and slowly lift the heat exchanger horizontally off the pallet (1)
- Remove the pallet and place two timber beams on the floor and slowly lower the plate heat exchanger on to the timber beams (2)
- IG, DG, FG, IS, DS frames: place lifting slings around the upper tie rods, on each side of the column (3a)
- ST frames: place a lifting sling (a loop) around the carrying bar (3b)
- Slowly raise the unit from its lying position on the timber beams. Use the foot units as support when raising the plate heat exchanger. Pay attention to the unit’s centre of gravity and not to damage the foot units (4)
- Remove the lifting slings and the timber beams. Once the unit is in an upright position follow the procedure “Lifting the unit from an upright position”.
- The plate heat exchanger is delivered on a pallet and can be packed in a wooden box or wrapped in stretch film. The centre of gravity as well as measurements and weight are marked on the box or on the stretch film.
CAUTION: Always be careful when raising the unit to avoid sliding and
damages to the equipment.
The frame type can be found on the data sheet or on the nameplate.
Lifting the unit from an upright position
The following description applies to all SONDEX® and Danfoss frame types with
a length longer than 2500 mm. These units are usually delivered standing
upright.
How to lift the unit:
Remove all tightening elements from the plate heat exchanger and the pallet
- Secure lifting shackles in the dedicated lifting lug on both the header and the follower (4 fixation points)
- Secure a lifting sling (4 fixation points) in each of the lifting shackles and carefully lift and move the unit to its final position
- Slowly lower the unit and mount the heat exchanger securely to the floor, using the foot units
- Remove the lifting slings and the shackles.
CAUTION: Always be careful when lifting the unit to avoid damages to the
plate heat exchanger.
CAUTION: Ensure the Centre of Gravity is well checked to prevent
unexpected tilting.
Transportation
Usually, the heat exchanger will be supplied horizontally on a pallet, this
applies to all SONDEX® and Danfoss frame types (ST, IG, DG, IS, DS) with a
length up to 2500 mm The back side of the head will then be secured to the
pallet. This allows the unit to be transported by means of a forklift truck.
WARNING: Make sure to fully support the pallet with the forklift forks
during transportation. Avoid tilting the pallet.
WARNING: The centre of gravity is not package centre-lined on the pallet.
Ignoring this warning might result in tiling forklift truck and material
damage.
Installing the pipe connections
- Most plate heat exchangers are intended for counter-current flow directions, but some specific applications require co-current flow. Refer to the nameplate for information about flow direction (inlet > outlet).
- Danfoss plate type heat exchangers are provided with various connection types depending on size, application, and design criteria, please refer to the data sheet/drawing for your specific connection type.
- Single plate heat exchangers are fitted with threaded pipe connections or studded flanges ready for counter/blind flanges.
- Semi-welded heat exchangers for industrial refrigeration are fitted with factory installed welding flanges. The refrigerant side is hermetically closed by blind plates and might be pressurized with nitrogen.
- Before connecting any piping to the plate heat exchanger make sure to clean and flush the piping system thoroughly for any foreign objects.
- When connecting the piping system to the plate heat exchanger make sure that the piping system does not subject the plate heat exchanger to stress or strain. Connections are designed to withstand suitable forces and moments indued by the piping. Please refer to the tables (fig. 25 and 26) indicating a suitable initial estimate of primary loadings for connections either in standard or severe service.
- Make sure that the piping system, connected to the plate heat exchanger, is secured against pressure peaks/surges and temperature shocks!
- When doing any welding for flange/valve/ pipe make sure that earthing is made next to the welding. Never use the heat exchanger for earthing as heat plates gaskets etc. might be severely damaged.
- Ensure during installation and setting- adjustments, that the (process) temperature will never exceed the temperature limits indicated on the name plate, to prevent gasket damage.
- When fitting threaded pipe to the threaded plate heat exchanger connection make sure that the connection does not rotate during tightening as this might damage internal ring gaskets. A secure counter-hold is needed (fig. 10).
- For studded (blind) flange connection, insert the gaskets before bolting the blind flanges to the head or follower.
- Tighten the bolts evenly – do not over-tighten as this might damage the bolts/threads.
Note:
- Identify actual flow inlets/outlets on the name plate before commencing piping work.
- Heavy piping should be supported. This will prevent heavy forces on the plate heat exchanger. If information about the max. nozzle load is required, please reach out to your local Danfoss sales rep.
- To be able to open/close and dismantle the plate heat exchanger, shut off valves should be installed in all connections.
- Depending on your application, blind flanges or plastic caps must be removed prior to start working on the piping system.
- Nitrogen pressurized refrigerant side must be depressurized through the small valve in the blind plate before removing the flanges.
- Always install flexible connections on the follower to prevent vibrations on the plate heat exchanger. The flexible connections also help prevent expansion of the pipes, which could be caused by temperature influence.
- Flexible connections must be fitted perpendicular to the header/follower.
- Install vents on side 1 and side 2 of the upper connections of the plate heat exchanger, at a minimum of a half inch. For additional information refer to the “Shut down – for a short period of time” section.
- The vents should be fitted on the highest point in the direction of the media flow.
- The installation must be fitted with safety valves according to current pressure vessel regulations.
Standard-service nozzle loading
Nom. size| PN6| PN10| PN16| PN25| PN40
F (N)| M (Nm)| F (N)| M (Nm)| F (N)| M (Nm)| F (N)| M (Nm)| F (N)| M (N*m)
DN25| 77| 0| 80| 0| 86| 0| 95| 0| 109| 0
DN40| 135| 35| 142| 36| 152| 36| 167| 37| 192| 38
DN50| 177| 73| 185| 74| 198| 74| 218| 76| 251| 78
DN80| 311| 221| 326| 224| 349| 227| 384| 232| 442| 240
DN100| 406| 343| 427| 347| 457| 353| 502| 362| 577| 377
DN150| 661| 707| 694| 719| 743| 737| 817| 764| 939| 809
DN200| 934| 1144| 981| 1170| 1050| 1209| 1154| 1268| 1327| 1366
DN250| 1221| 1642| 1282| 1690| 1372| 1761| 1508| 1869| 1734| 2047
DN300| 1520| 2197| 1595| 2275| 1708| 2392| 1877| 2568| 2159| 2860
DN350| 1829| 2806| 1920| 2924| 2055| 3101| 2258| 3368| 2597| 3811
DN400| 2147| 3466| 2253| 3635| 2412| 3890| 2651| 4272| 3049| 4908
DN450| 2473| 4176| 2595| 4409| 2779| 4759| 3054| 5284| 3512| 6159
DN500| 2807| 4936| 2945| 5246| 3153| 5711| 3465| 6408| 3985| 7571
Standard-service nozzle loading
Nom. size| PN6| PN10| PN16| PN25| PN40
F (lbf)| M (lbfft)| F (lbf)| M (lbfft)| F (lbf)| M (lbfft)| F (lbf)| M
(lbfft)| F (lbf)| M (lbf*ft)
DN25| 17| 0| 18| 0| 19| 0| 21| 0| 25| 0
DN40| 30| 26| 32| 27| 34| 27| 38| 27| 43| 28
DN50| 40| 54| 42| 55| 45| 55| 49| 56| 56| 58
DN80| 70| 163| 73| 165| 78| 167| 86| 171| 99| 177
DN100| 91| 253| 96| 256| 103| 260| 113| 267| 130| 278
DN150| 149| 521| 156| 530| 167| 544| 184| 563| 211| 597
DN200| 210| 844| 221| 863| 236| 892| 259| 935| 298| 1008
DN250| 274| 1211| 288| 1246| 308| 1299| 339| 1379| 390| 1510
DN300| 342| 1620| 359| 1678| 384| 1764| 422| 1894| 485| 2109
DN350| 411| 2070| 432| 2157| 462| 2287| 508| 2484| 584| 2811
DN400| 483| 2556| 506| 2681| 542| 2869| 596| 3151| 685| 3620
DN450| 556| 3080| 583| 3252| 625| 3510| 687| 3897| 790| 4543
DN500| 631| 3641| 662| 3869| 709| 4212| 779| 4726| 896| 5584
Standard-service nozzle loading
Inch| PSI 100| PSI 150| PSI 250| PSI
300| PSI 400
F (N)| M (Nm)| F (N)| M (Nm)| F (N)| M (Nm)| F (N)| M (Nm)| F (N)| M (N*m)
1| 77| 0| 81| 0| 87| 0| 91| 0| 97| 0
2| 179| 73| 186| 74| 201| 75| 209| 75| 224| 76
3| 314| 222| 328| 224| 354| 228| 367| 229| 394| 233
4| 411| 344| 428| 347| 463| 354| 480| 358| 515| 365
6| 669| 710| 697| 720| 753| 741| 781| 751| 838| 772
8| 945| 1149| 984| 1172| 1064| 1217| 1104| 1239| 1183| 1285
10| 1235| 1653| 1287| 1694| 1391| 1776| 1443| 1817| 1547| 1899
12| 1537| 2214| 1602| 2282| 1731| 2416| 1796| 2484| 1925| 2618
14| 1849| 2832| 1927| 2934| 2083| 3138| 2161| 3240| 2317| 3444
16| 2171| 3504| 2262| 3650| 2445| 3942| 2537| 4089| 2719| 4381
18| 2501| 4228| 2606| 4429| 2817| 4831| 2922| 5032| 3132| 5434
20| 2838| 5005| 2957| 5273| 3196| 5807| 3316| 6074| 3555| 6608
Standard-service nozzle loading
Inch| PSI 100| PSI 150| PSI 250| PSI
300| PSI 400
F (lbf)| M (lbfft)| F (lbf)| M (lbfft)| F (lbf)| M (lbfft)| F (lbf)| M
(lbfft)| F (lbf)| M (lbf*ft)
1| 17| 0| 18| 0| 20| 0| 20| 0| 22| 0
2| 40| 54| 42| 55| 45| 55| 47| 55| 50| 56
3| 71| 164| 74| 165| 80| 168| 83| 169| 89| 172
4| 92| 254| 96| 256| 104| 261| 108| 264| 116| 269
6| 150| 524| 157| 531| 169| 547| 176| 554| 188| 569
8| 212| 847| 221| 864| 239| 898| 248| 914| 266| 948
10| 278| 1219| 289| 1249| 313| 1310| 324| 1340| 348| 1401
12| 346| 1633| 360| 1683| 389| 1782| 404| 1832| 433| 1931
14| 416| 2089| 433| 2164| 468| 2314| 486| 2390| 521| 2540
16| 488| 2584| 509| 2692| 550| 2907| 570| 3016| 611| 3231
18| 562| 3118| 586| 3267| 633| 3563| 657| 3711| 704| 4008
20| 638| 3691| 665| 3889| 718| 4283| 745| 4480| 799| 4874
Tightening sequence
To obtain a leak-free flange connection the bolt tension must be tightened
correctly according to the described tightening sequence..
First pass
Lightly tighten the bolts, to 30% of the final torque value.
Second pass
Tighten the bolts to a maximum of 60% of the final torque value.
Third pass
Tighten the bolts to the final torque value.
Flanges with gasket grooves (Narrow ring gaskets) Carbon Steel Bolts Class 8.8
Nom. size| PN16| PN25| PN40
Qty.| Size| Torque [Nm]| Qty.| Size| Torque
[Nm]| Qty.| Size| Torque [Nm]
DN65| 8| M16| 65| 8| M16| 60| 8| M16| 55
DN65| 4| M16| 135| –| –| –| –| –| –
DN80| 8| M16| 75| 8| M16| 70| 8| M16| 60
DN80| 4| M16| 140| –| –| –| –| –| –
DN100| 8| M16| 130| 8| M20| 150| 8| M20| 130
DN150| 8| M20| 230| 8| M24| 250| 8| M24| 230
DN200| 12| M20| 200| 12| M24| 220| 12| M27| 230
DN250| 12| M24| 295| 12| M27| 310| 12| M30| 320
DN300| 12| M24| 345| 16| M27| 275| 16| M30| 290
DN350| 16| M24| 385| 16| M30| 455| 16| M33| 465
DN400| 16| M27| 490| 16| M33| 565| 16| M36| 590
DN500| 20| M30| 545| 20| M33| 570| 20| M39| 655
DN600| 20| M33| 715| 20| M36| 760| 20| M45| 920
Flanges Flat Face (Wide gaskets) Carbon Steel Bolts Class 8.8
Nom. size| PN16| PN25| PN40
Qty.| Size| Torque [Nm]| Qty.| Size| Torque
[Nm]| Qty.| Size| Torque [Nm]
DN50| 4| M16| 165| 4| M16| 170| 4| M16| 175
DN65| 8| M16| 145| 8| M16| 150| 8| M16| 155
DN65| 4| M16| 109| –| –| –| –| –| –
DN80| 8| M16| 155| 8| M16| 160| 8| M16| 165
DN80| 4| M16| 205| –| –| –| –| –| –
DN100| 8| M16| 160| 8| M20| 285| 8| M20| 295
DN150| 8| M20| 300| 8| M24| 495| 8| M24| 510
DN200| 12| M20| 300| 12| M24| 500| 12| M27| 730
DN250| 12| M24| 490| 12| M27| 740| 12| M30| 1030
DN300| 12| M24| 545| 16| M27| 745| 16| M30| 1055
DN350| 16| M24| 595| 16| M30| 1075| 16| M33| 1485
DN400| 16| M27| 830| 16| M33| 1440| 16| M36| 2015
DN500| 20| M30| 1130| 20| M33| 1490| 20| M39| 2310
DN600| 20| M33| 1590| 20| M36| 1960| 20| M45| 3635
Flanges Flat Face (Wide gaskets) Carbon Steel Bolts SA 193
| 150 psig| 300 psig
ANSI B16.5| Qty.| Size| Torque [Nm]| Qty.|
Size| Torque [Nm]
2”| 4| 5/8| 170| 8| 5/8| 131
2.5”| 4| 5/8| 188| 8| 3/4| 155
4”| 8| 5/8| 285| 8| 3/4| 295
6”| 8| 3/4| 495| 12| 3/4| 383
8”| 8| 3/4| 625| 12| 7/8| 730
12”| 12| 7/8| 931| 16| 9/8| 1055
For threaded connections, use a pipe wrench to hold the nozzles in place when
connecting the pipes, as the pipes may rotate and potentially damage the
internal gasket.
Always remember to lubricate the threads with suitable grease or similar
lubricant, before tightening the torques.
Operation
Commissioning
Commissioning, control during operation, maintenance and repair of the
installation should be done by authorized, trained, and properly instructed
staff. Before commissioning check if all connections are fitted and tightened
correctly and that the A-measure is correct according to the nameplate Measure
AF1, AF2, AF3, AF4 dimension according to fig. 35. Check the pressures and the
temperatures of the media and make sure they are within the limits of the
values specified on the name plate. The plate heat exchanger must not be
subject to thermal or mechanical shock as this could lead to premature gasket
failure. Commissioning of heat exchangers containing refrigerants must always
comply to local regulations and legislation.
Start-up process – Single plate heat exchanger
For plate heat exchangers with liquid on both sides (liquid/liquid flow), the
flow with an operating temperature closest to the ambient temperature is to
start first. Assumed is, that no back pressure is present and check valves in
piping will prevent backflushing effect when the plate heat exchanger return
valves are opened. Also assumed is that bleed valves can safely be opened (no
extreme pressure, vapours, gasses, or temperatures), that could harm
environment or operators. Local precautions to be taken to make such a safe
operation.
Side 1 (cold) / Flow 1
Delta T to ambient temperature lowest.
- Ensure that valve 10 is closed
- Open return valve on cold side (1)
- Open air bleed valve on cold side (2)
- Start pump on cold side (3)
- Gradually open supply valve on cold side (4) and close air bleed valve (2) when no further air is present in the system
Side 2 (warm) / Flow 2
Delta T to ambient temperature highest.
- Ensure that valve 9 is closed
- Open return valve on warm side (5)
- Open air bleed valve on warm side (6)
- Start pump on warm side (7)
- Gradually open supply valve on warm side (8) and close air bleed valve (6) when no further air is in the system
Inspect for leakages
Start-up process – Semi-welded heat exchanger
For semi-welded plate heat exchangers with refrigerant on one side and
glycol/water on the other side, the glycol/water side, i.e., the liquid flow,
must be started first.
Start liquid flow first, then refrigerant flow
For the liquid flow follow steps mentioned above. For refrigerant flow follow
these steps:
- Keep shut-off valves at the plate heat exchanger connections closed, while evacuating the heat exchanger completely
- Gradually open the shut-off valve at the outlet for pressure equalization and subsequently gradually open the inlet to the heat exchanger
- Activate Side 2 following the previous described procedure
Check during operation
For proper and safe operation of single plate and semi-welded heat exchangers:
- Check the system for potential pressure pulses caused by pumps or control valves. In case of pressure pulses, stop operation and rectify
- Continuous pressure pulses could cause fatigue issues of flow plates, so you need to prevent them from happening or lower down to possible minimum level
- Check that no leakages appear from the unit
- Check that all vents are closed to prevent air being sucked into the system
- Check that the operating conditions including media temperatures and pressures are within the limitations stated on the name plate. These values may not be exceeded.
Water hammering occurs when a fluid media is abruptly stopped or forced to
abruptly change direction, and the same would happen if live steam injection
is used. This creates a pressure spike moving upstream in the system with a
velocity of 1500 meters per second (i.e., faster than a bullet). Water hammer
may cause considerable damage to the equipment and cause refrigerant leakage
to the surroundings.
WARNING: If a wedge is inserted between the follower and the carrying
bar, remove it before commissioning. The wedge is inserted to ensure that no
displacements occur when the exchanger is lifted or during transportation.
Shut down – for a short period of time( <12 hours)
If the plate heat exchanger must be shut down for a short period up to 12
hours, then the following procedure should be followed:
Side 2 (warm) /Flow 2
- Close supply valve on side 2 (warm) (1)
- Stop pump on side 2 (warm) (2)
- Close return valve on side 2 (warm) (3)
Side 1 (cold) /Flow 1
Maintain flow on side 1 (cold) until the heat exchanger temperature is <40°C
or close to the ambient working temperature, then
- Close supply valve side 1 (cold) (4)
- Stop pump on side 1 (cold) (5)
- Close return valve on side 1 (cold) (6)
Close any other connected valves, and check that device is fully depressurized and drained, and ready for e.g., disassembly.
Shut down – for a long duration ( > 12 hours)
Ensure after the heat exchanger has been closed in, that drain valves 9 and 10
are opened and that bleed valves X and Y are opened to facilitate drainage,
see fig. 34. For long duration (>1 month); prior to close in the heat
exchanger it must be flushed with clean liquid (application depending) and the
heat exchanger, should be stored in no freezing conditions. If the unit is to
be shut down for an extended period (more than a few hours) then the following
procedure should be followed:
- Follow the shut down – for a short period of time procedure
- Drain the plate heat exchanger completely
- Rinse/flush the plate heat exchanger and let it dry
- All connections should be covered to prevent any dirt or water/moisture to enter the plate heat exchanger.
- Lubricate threads on the tie rods
- If you are shutting down the plate heat exchanger for more than one month: Loosen tie rods according to the instruction in “opening the plate heat exchanger” section until the length of the plate pack reaches: A-measure nominal +10%
- Cover the plate pack with black plastic to exclude any sunlight
- See the “Storage” section for additional information about storage of the plate heat exchanger for a longer period.
It is recommended to attach a warning notice to the plate heat exchanger to remind personnel that the tie rods need adjustment before the unit can be put back into service
Opening the plate heat exchanger
CAUTION: Ensure unit is depressurized and drained and flushed of hot
and/or aggressive fluid before unit is opened to prevent personal injury.
Before disassembly clean the threads and give them a light coat of suitable
grease or similar lubricant. Use appropriate tools for the disassembly.
When opening and disassembling the plate heat exchangers observe the following:
- Mark the plate package before opening. This can be done by a diagonal line or by numbering each individual plate in sequence
- Measure and note the actual assembly measure (Reference name plate for validation).
- Shut down the heat exchanger as described in section “Shut down”
- Make sure the heat exchanger cools down to the ambient temperature 1<T<40°C (104 °F)
- The heat exchanger should be totally drained on both sides before opening.
- Measure (or read from the label) the A-measure.
- Loosen the tie rods should be done slowly (with small nut travel distance along the tie rod) when you are close to nominal A-measure. The further away from the nominal A-measure you go, bigger nut travel distances can be used.
- Lose the tie rods in max nut travel distance of 3 mm until you reach the A-measure = A nominal (measured/from label) +5%. At this point you can totally loosen and take away pairs of tie rods from top and bottom (indicated as 1 in fig. 35).
- Lose all remaining tie rods with max. travel distance of a nut 6 mm until you reach the A- measure = A nominal + 10%. At this point you can loosen (with max travel 50 mm at once) all remaining short tie rods, if the heat exchanger height is less then 1500 mm. If the height is bigger, keep the short tie rods in place until A-measure = A nominal + 15%.
- Start losing the long tie rods in sequence 2, 3, 4, 5 with maximum nut travel distance of 25 mm until all bars and nuts are loose.
- When the follower is no longer under compression from the plate pack, it can be slid backwards, and the individual plates/cassettes can be inspected and/or removed. For followers with a roller (IS or DS-frames) we recommend making sure they can’t accidentally move along the carrying bar during service. You can strap them to the column.
While opening the plate heat exchanger extra caution must be paid to prevent
the plates sliding off the carrying bar
CAUTION: In case of incorrect disassembly, asymmetric load on tie rods
might happen. Example: tie rod 1 are removed and tie rods 2, 4, 3 are totally
loose, then most of the tightening load will be on tie rod 5. There is a risk
that the thread will not be able to withstand such load and the nut might
“shoot” forward as the thread will be cut off. DO NOT stand directly in front
of the tie rods, due to possible nut trajectory and risk of personal injury,
when assembling or dissembling the unit.
CAUTION: Do not loosen one or all tie bolts fully at once. Loosen the tie
bolts slowly, little by little in the sequence shown in fig. 35. If a
hydraulic tool is used to loosen the tie bolts, the tool must be set on lowest
speed.
CAUTION: The plates/cassettes have sharp edges! Always use personal
protective equipment when handling plates/cassettes to prevent injuries on
hand/arms.
Plate/cassette replacement
If a plate/cassette must be renewed because of serious damage, it is
recommended to replace the plates/ cassettes as well as the plates/cassettes
next to this plate/cassette.
- Plates/Cassettes must be replaced if damaged or not cleanable
- When ordering new plates/cassettes all data from the nameplate is required
- New plates/cassettes can be supplied with complete gaskets ready for immediate installation.
CAUTION: The plates/cassettes have sharp edges! Always use personal protective equipment (gloves as a minimum requirement) when handling plates/cassettes to prevent injuries on hand/arms.
Gasket replacement
Glue free gaskets i.e., SonderLock, Hang-on, D-LockTM gaskets – these gaskets
are mounted without the use of any glue. They are attached to the plate by
pushing the gasket fully down into the gasket groove or fastened by special
devices i.e., SonderLock pins, Hang-on clamps or D-LockTM. Make sure that the
gasket groove and gasket are clean.
Glue type gaskets
The surfaces must be clean and free from oil. Recommended glue/adhesive
DOWSIL™ 786 Silicone Sealant-M Clear or 3M 1099. Follow the instructions of
the manufacturer.
Semi-welded gaskets
The 2 types of gaskets in Semi-welded heat exchangers – ring gaskets for
refrigerant side and field gasket for liquid side – can be replaced
independently (see fig. 8).
CAUTION: When using commercial solvents and adhesives, follow the
manufactures recommendations carefully. Most of these solvents are hazardous.
CAUTION: Always follow local regulations and legislation regarding
recycling and scrapping of any of the components.
D-plates
When ordering D-plate the hanging insert is already mounted on the plate.
-
Fitting the diagonal reinforcement
The diagonal reinforcement is made from an advanced glass-fibre reinforced polymer, able to withstand a wide range of chemicals, acids and alkalis fluids and it withstands temperatures from a range of -20C to +180°C. The diagonal reinforcement is not considered a service part during normal gasket replacement but can be easily replaced if lost during servicing.
For any further information please reach out to your local Danfoss representative or your local Danfoss company.- Flow connections = the port hole without the diagonal reinforcements.
- Left / Right definition = when facing flow connections as illustrated below in fig. 38
-
Fitting the gasket
The patented D-Lock™ gasket system is easy to attach. It snaps the gasket into the D-Lock™ sockets and keeps the gasket firmly in place.
Place the gasket on top of the plate and the reinforcements and click the D-lock™ in place by following the number sequence 1 to 26 as illustrated below . -
Fitting of start plate
The D-plate series usually comes with a dedicated start plate, however if the start plate is missing it can easily be made from an ordinary flow plate.
To ensure that the start plate lies completely flat against the head, the plates corner locks must be removed – this can be done with an angle grinder, fitted with a standard cutting disc of 1.0 to 1.5 mm thickness.
Closing the heat exchanger
Before closing the heat exchanger clean the threads and give them a light coat
of suitable grease or similar lubricant, if not already done. Use appropriate
tools e.g., a ratchet spanner for the disassembly. When assembling and closing
the heat exchanger observe the following:
- Check that all gaskets are correctly attached on the plates/cassettes
- Check that plates/cassettes are hanging correctly on the carrying bar
- Press the plate pack together by pushing the follower towards the head.
- Make sure the plates/cassettes are in the correct position according to the marked diagonal line or the sequential numbering
- Check the plate/cassettes honeycomb profile for uniformity (see fig. 41)
- Identify the A-measure noted prior to opening the heat exchanger (confirm with nameplate)
- Ensure there is no flow to any part of the unit
- Clean the tie rods and grease the threads, if not already done
- Put long tie rods in corresponding positions. Start tightening them with small increments (always keeping diagonal sequence of tightening 1,2,3,4) until you reach A-measure = A- measure nominal +10%.
- Put all short tie rods (except top no. 7 and 5 and bottom no. 8 and 6) in positions. Proceed tightening with maximum travel of nut 6 mm, following diagonal sequence until you reach A- measure = A-measure nominal +5%. For heat exchangers with height equal or bigger than 1500 mm, tighten the short tie rods as soon as you have possibility to do it, and use them for tightening the plate pack together with the long tie rods.
- Add remaining short tie rods to top and bottom positions, proceed tightening with maximum travel of nut 3 mm, following diagonal sequence until you reach A-measure = A-measure nominal.
- Prepare for operation. Follow instructions in section “Start-up process”
- If the heat exchanger does not seal immediately the tie rods can gradually be tightened to A-measure minimum. Please refer to the A-measure stated on the nameplate.
Maximum allowable deviation of parallelism between header and follower of the frame is 5 mm. That means after tightening the frame to required plate pack dimension, difference of A-measure in different corners of plate pack, along tie rods 1, 2, 3, 4 should not deviate more than 5 mm.
Maintenance
CIP cleaning
Clean-in-Place, CIP cleaning, allows cleaning the plate heat exchanger without
opening it and is done by circulating cleaning agents in the heat exchanger.
Refrigeration units:
CIP cleaning of the refrigerant circuit is not allowed. CIP cleaning can be
done only on the brine circuit.
The use of CIP cleaning is relevant for soluble fouling only. Prior to CIP cleaning ensure that all materials in the entire circulation system are resistant to the cleaning agent/CIP liquid used. Check maximum allowable working temperature on the nameplate mounted on the head of the plate heat exchanger before performing CIP cleaning. Maximum working temperature should not be exceeded at any time. Consult Danfoss if in doubt. If the solution requires recirculation, select a flow that is as high as possible (but not higher than stated on the data sheet to prevent over-pressure), and no less than the service or operation flows. Follow the instructions from the supplier of the cleaning agent. For re-circulated cleaning, we recommend that fluid is circulated in the plate heat exchanger for no less than 30 minutes and no longer than 4 hours.
Rinsing
After using any type of cleaning agent, always rinse the plate heat exchanger
thoroughly with fresh water. After CIP cleaning, circulate fresh water for at
least 10 minutes.
We advise to ask for a confirmation from the supplier of the cleaning agent that it will not damage the materials and other process components in the heat exchanger.
Cleaning agents’ guidance
Oil and grease can be removed with a water emulsifying oil solvent. Organic
and grease cover can be removed with sodium hydroxide (NaOH) maximum
concentration 1.5% – max. temp. 85 °C (185 °F). Mixture for 1.5% concentration
= 5 l 30% NaOH per 100 l water.Stone and limestone can be removed with nitric
acid (HNO₃), max. concentration 1.5%, max. temp. 65 °C (Mixture for 1.5%
concentration = 2.4 l HNO₃ 62% per 100 l water).
Do not exceed the max. concentration or max. temperature as nitic acid is very
corrosive toward carbons teel frame parts and tie rods. Nitric acid has a
build-up effect on the passivation film of stainless steel.
CAUTION: Nitric acid and Sodium Hydroxide may cause injury to exposed
skin, eyes, and mucous membranes. Use of protective eyewear and gloves is
strongly recommended.
Cleaning a flow plate
Use a brush with stiff bristles (non-metallic) and use water hose or low-
pressure lance. It is recommended to lay the heat plate on a flat surface when
cleaning to avoid the risk of bending the plate. Use suitable cleaning
solutions, depending on the type of fouling and plate/gasket material. Welded
cassettes are only cleanable on the brine side and all precautions must be
taken to avoid any water or cleaning agent entering inside the cassettes.
Single plates may be immersed into a solvent bath to dissolve hard fouling. We
strongly recommend that gaskets are always removed prior to cleaning as there
is otherwise a risk that acidic cleaning agents can be trapped behind/around
the gasket. When the water in the cleaning agent evaporates, the acid
concentration increases, with risk of corrosion consequently.
Always wear suitable protection when working with acidic or caustic solutions. Always wear gloves when handling plates.
CAUTION:
- Some cleaning agents may cause injury to exposed skin, eyes, and mucous membranes.
- Never allow any water or cleaning agent to enter the welded side of the cassettes.
- Never use abrasive materials (wire brushes, emery cloth, sand/glass paper, angle grinders or similar) when cleaning a heat exchanger plate. This will damage the surface and the passivation film of the plates and may cause faster fouling, or in worst case penetrate the thin material.
- Never use Hydrochloride for stainless steel plates.
- Never use Hydrofluoric for titanium plates.
- Before fitting chemical cleaned plates, they must be thoroughly rinsed with fresh water.
Regular service of the plate heat exchanger
Service sequence – once a year as a minimum
- Check temperatures and flows against commissioning data
- Check general condition and look for any signs of leakage
- Wipe clean, all painted parts and check surfaces for signs of damage – “touch up” if necessary
- Check bolts and bars for rust and clean. Coat threaded parts with molybdenum grease or a corrosion inhibitor (ensure that no grease, etc. falls onto the plate gaskets.
Years after commissioning| Clean fluids/normal conditions|
Dirty fluids/severe conditions
---|---|---
2| –| PHE audit| Leak detection| CIP and manual cleaning| Replace ring
gaskets
3| PHE audit| Leak detection| CIP cleaning| –
5| PHE audit| Replace ring- and flow gaskets| Leak detection| CIP and
manual cleaning| PHE audit| Replace ring- and flow gaskets| Leak detection|
CIP and manual cleaning
6
7| PHE audit| Leak detection| CIP cleaning| –| PHE audit| Leak
detection| CIP & manual cleaning| Replace ring gaskets
8
10| Replace ring- and flow gaskets| Leak detection| CIP and manual
cleaning| –| PHE audit| Replace ring- and flow gaskets| Leak detection|
CIP & Mmanual cleaning
12
13| PHE audit| Leak detection| CIP cleaning| –| PHE audit| Leak
detection| CIP & manual cleaning| Replace ring gaskets
15
PHE audit: Visual inspection of operating conditions, leaks, corrosion,
and general condition
CIP: Clean in place (See section “clean in place”)
Manual cleaning: Plate pack disassembly/plate cleaning Replace gaskets:
Plate pack disassembly/replace gaskets At extreme fluids/conditions audits
should be performed more frequent
Troubleshooting
Most common problems with a plate heat exchanger, can be solved by own trained personnel. Below table lists a summary of possible problems together with relevant possible causes and solutions. To maintain a continuous proper function of the plate heat exchanger, it is essential to keep the operating pressure and temperature within the ranges stated on the nameplate. Exceeding these values, even as short-lasting peaks, may damage the unit or could be the cause of problems/issues. To avoid costly repairs, it is recommended to have the installation and maintenance carried out by properly trained personnel.
Problem | Possible cause | Possible solution |
---|
Leakage
|
Connection sealing damaged
| Check the rubber liners (if fitted)
Check the flange gasket (if fitted)
Check the ring gasket at first plate
Fit the pipes tension-free
Mixing of primary and secondary circuit
| Check the plates for holes and/or cracks
Check the diagonal part of the field gasket and ring gasket
Plate package sealing damaged
| Check the assembly distance “A”
Check the condition of the gaskets
Check the proper position of the gaskets
The operating conditions deviate from the specification| Adjust the operating
conditions
Insufficient capacity
| Air in the system| Vent the piping system
Check the pipe work for possible air traps
The operating conditions deviate from the specification| Adjust the operating
conditions
The heat exchanger is fouled internally| Clean the heat exchanger
The connections have been interchanged| Redo the pipe work
Too high pressure drop
| Flow larger than the design flow| Adjust the flow
Channels in plates blocked| Flush / clean
Incorrect measurement| Check the pressure indicator
Fluid deviating from the specification| Check the chemical composition
Air in the system| Vent the piping system
Check the pipe work for possible air traps
For nearly all leakage problems it will be necessary to dismantle the unit before any attempts to rectify the fault can be made. Mark the area(s) where the leakage seems located with a felt tip marker or similar before disassembling the plate heat exchanger. Follow the instructions in section “Opening the plate heat exchanger”. “Cold leakage” is caused by a sudden change in temperature. The sealing properties of certain elastomers are temporarily reduced when the temperature changes suddenly. No action is required as the gaskets most often re-seal after the temperature has stabilized.
Gasket failures
Gasket failures are generally a result of
- Material aging/degradation
- Excessive exposure to ozone
- High or low operating temperature – outside specified material limits
- Exposure to pressure surges
- Attack by chemicals from cleaning, refrigerants, or oils
- Physical damage from incorrect assembly work
- Misaligned plates (check the hanging system at the top of the plate for distortion)
Decrease in performance
Decrease in performance is generally a result of
- Plate surfaces require cleaning or de-scaling
- Pumps or associated controls failing
- Plate channels blocked
- Liquid flows not as specified
- Associated chiller / cooling tower / boiler under sized or dirty
- Cooling fluid temperature to the plate heat exchanger is higher than the design temperature
- Heating fluid temperature to the plate heat exchanger is lower than the design temperature
- Refrigerant trap broken or jammed – unit becomes filled with condensate
- Plate package has been assembled incorrectly
- Plate heat exchanger is running with co-current flow, instead of counter current. (Check direction of pump flows)
- Air trap has developed in the plate package or piping work
After sales service
Ordering parts
When ordering spare parts, it is important to provide correct data for:
- Plate heat exchanger type and serial number. On the nameplate a unique serial number is stated, this will be needed to ensure correct spare part selection as well as trouble shooting advise
- Required parts
Also indicate if there have been any design changes of the plate heat exchanger since commissioning date. When ordering separate plates, it is important that the correct plate code index (the plate code index describes which port holes are open e.g., 1234 means that all portholes are open, 0000 means that all port holes are blinded (end plate)) and type of plate is stated e.g., plate material, plate thickness, thermal plate pattern TS/TL etc. Also, gasket material and liner type is required for correct spare part delivery or on-site service. When ordering separate gaskets, it is important to indicate the correct gasket material. When ordering tie rods, the existing bolts should be measured to get spare bolts with the same dimensions.
Modifications to the heat exchanger
Please note that a plate heat exchanger is specific designed and built for the
operating parameters (pressures, temperatures, capacity, and type of fluids)
initially provided by the customer. If the plate heat exchanger needs to
operate at a different capacity this can be achieved by adding or removing
plates/cassettes. Modification of the plate heat exchanger to match other
parameters may also be considered. Consult Danfoss for redesign and/or
approval of any change to operating parameters. After approval by Danfoss a
new name plate will be issued. You may only commission a plate heat exchanger
under modified conditions after written approval by Danfoss
- Always use genuine parts – Danfoss cannot guarantee performance or product lifetime, etc., when using parts from other product brands.
- For any questions regarding spare parts reach out to your local Danfoss representative or your local Danfoss (Service) company.
Scrapping
At end of use, the heat exchanger should be dismantled, and its components
sorted, recycled, and scraped, according to local regulations and legislation.
For any further information please reach out to your local Danfoss
representative or your local Danfoss company.
Always follow local regulations and legislation regarding recycling and
scrapping.
Danfoss A/S
Climate Solutions • danfoss.com • +45 7488 2222
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oraliatiotonia yount de sia doveria, shane considered ormative, technical data
in grifanct to anuals, extent, explicit reference is made in a quotation or
order confirmation. Danfoss cannot accept any responsibility for possible
errors in catalogues, brochures, videos and other material. Danfoss reserves
the right to alter its products without notice. This also applies to products
ordered but not delivered provided that such alterations can be made without
changes to form, fit or function of the product. All trademarks in this
material are property of Danfoss A/S or Danfoss group companies. Danfoss and
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