UPGR KNOWLEDGE · HVAC

Gasketed plate heat exchangers

A compressed pack of plates and replaceable gaskets sits in a frame. Opening the pack gives access to the heat-transfer surfaces for inspection and cleaning.

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Hot stream →← Cold stream

Grey lines are separating plates. The dashed arrow shows heat transfer through a plate.

Conceptual counterflow channel section, not to scale. Other flow arrangements exist; actual paths and port positions depend on the design.

Plate heat exchanger overview

Gasketed heat exchanger components

A gasketed unit combines a plate pack, seals, a load-bearing frame, guiding elements and piping connections. The inventory below identifies the parts individually; optional details must be checked against the equipment drawing and parts list. This list locates each part; the following sections explain servicing and replacement identification.

Heat-transfer plate
Forms the heat-transfer surface and flow channels.
End and pass-divider plates
Closes or divides the specified flow arrangement.
Plate gasket
Seals the plate channels.
Port and end-position seals
Seals port interfaces and end positions.
Fixed frame plate
Provides the fixed end of the frame.
Movable pressure plate
Compresses the pack and moves for service.
Upper carrying bar
Suspends the plates and supports movement during service.
Lower guiding bar
Keeps the lower plate positions aligned.
Rear support column
Supports the rear end of the frame structure.
Pressure-plate roller and suspension
Supports movement of the pressure plate where fitted.
Tie bolts or tie rods
Clamps the plate pack to the specified dimension.
Nuts, washers and bearing boxes
Transfers the tightening force at the tie bolts.
Nozzles and flange connections
Connects the exchanger to the external circuits.
Connection liners and flange seals
Lines or seals the specified connection interface.
Support feet and anchoring brackets
Positions and anchors the frame on its foundation.

Applications and selection conditions

Service access is one reason to consider a gasketed construction, but the gasket, plate and channel design must suit the fluid and duty. Hygienic product contact requires an appropriate execution and documentation; it cannot be inferred from dismantlability.

Heating and domestic hot water

Specify the temperatures, flows and allowable pressure losses of the separate circuits. In domestic hot water duty, include the water quality and required product-contact conditions.

Process fluids and heat recovery

Compare plate and gasket compatibility, channel geometry and required cleaning access. Dismantlability is a service property, not proof of suitability for every fluid.

Plates

Heat-transfer plate

A profiled metal sheet separates the fluids and transfers heat. Its corrugations, distribution area, port openings and gasket groove form one part.

During servicing: With the pack open, inspect both faces, the sealing groove and the hanging points. Retain the specified plate order and orientation.
For replacement: Plate code, corrugation pattern, port configuration, metal grade, thickness and hanging arrangement. The same outer dimensions do not establish interchangeability.

End and pass-divider plates

The first, last and any pass-divider plates complete the specified flow arrangement. Their openings and gasket layout may differ from an ordinary channel plate.

During servicing: Keep each special plate in its documented position. A thin end plate inside the pack is distinct from the thick pressure plate of the frame.
For replacement: Exact position in the plate-hanging list, part code, open and closed ports, and the gasket arrangement specified for that position.

Gaskets and seals

Plate gasket

The shaped elastomer gasket seals the plate perimeter and separates flow paths around the ports. Its profile follows the plate groove.

During servicing: Check seating, damage and loss of elasticity. Clip-on and bonded gaskets use different fitting procedures; the groove must be prepared for the specified system.
For replacement: Plate and gasket codes, elastomer grade, attachment method and operating fluids. EPDM, NBR or FKM identifies a material family, not a complete part specification.

Port and end-position seals

Separate ring seals or a special end gasket may be used at particular positions. The sealing arrangement is defined by the plate-pack drawing.

During servicing: Identify these seals separately when dismantling. A ring seal, a connection liner and a flange gasket perform different jobs.
For replacement: Position, ring or gasket code, section, material and quantity from the equipment parts list; do not order solely by the port diameter.

Frame plates and supports

Fixed frame plate

The stationary end of the frame carries the fixed side of the compressed pack and the bar attachments. Connections are often located on this plate.

During servicing: Check the supporting structure, connection zones and bar attachments. It normally remains in position while the plate pack is opened.
For replacement: Frame designation, drawing revision, connection execution and manufacturer part number. Plate-pack size alone does not identify the frame plate.

Movable pressure plate

The movable frame plate closes the pack against the fixed plate. It moves away from the pack to provide service access.

During servicing: Keep the movement parallel to the fixed plate as specified in the manual. Any connections on the movable plate must allow the required service movement.
For replacement: Frame type, thickness and connection execution, suspension or roller arrangement, and the corresponding drawing.

Support feet and anchoring brackets

Transfer the frame load to its foundation and provide the specified fixing points. Their arrangement depends on the frame.

During servicing: Check stability, fasteners and foundation condition before opening a heavy pack. Leave the service clearance required by the manufacturer.
For replacement: Support drawing, mounting-hole pattern and corresponding frame designation.

Carrying bar and guiding system

Upper carrying bar

Supports the suspended plates and, in the relevant frame design, the pressure plate. Plates move along it when the pack is opened.

During servicing: Inspect the running surface, attachment points and the available travel. The manufacturer determines how plates are removed from the bar.
For replacement: Frame series, bar profile, length, attachments and hanging geometry. A lower guiding bar is not a substitute for this load-bearing part.

Lower guiding bar

Locates the lower edges of the plates and helps keep the pack aligned. In the relevant design it also guides the pressure plate.

During servicing: Check for damage, dirt and misalignment before moving or rehanging plates. Dismantling the guiding bar is not a universal opening step.
For replacement: Profile, length, plate engagement geometry and fastening points from the frame drawing.

Rear support column

Supports the free ends of the frame bars in a column-type frame. Compact frames can use a different supporting arrangement.

During servicing: Check the bar joints, stability and foundation attachment. The column is part of the frame support, not a stop to force the pressure plate against.
For replacement: Frame execution, height, bar attachment pattern and support-foot arrangement.

Pressure-plate roller and suspension

Where fitted, a roller or carriage helps the heavy pressure plate travel along the carrying bar. Its position and construction vary by frame.

During servicing: Check free travel and the condition of the roller, axle and retainers before moving the pressure plate.
For replacement: Roller or carriage assembly code, bearing or axle specification, mounting arrangement and frame model.

Plate-pack tightening hardware

Tie bolts or tie rods

Apply the clamping force that compresses the plate pack between the fixed and movable plates. Their layout belongs to the frame design.

During servicing: Inspect threads and load-bearing surfaces. Use the equipment-specific opening sequence, closing sequence and final pack dimension.
For replacement: Part number, length, thread, strength specification and coating. Connection studs and tie bolts are separate items.

Nuts, washers and bearing boxes

Nuts and washers transfer the tightening load. Some frames include bearing boxes or other friction-reducing hardware.

During servicing: Keep the specified hardware arrangement and inspect damaged threads or bearing surfaces. A bearing box is present only where the frame specification includes one.
For replacement: Thread, strength, washer dimensions and any bearing-box assembly code from the parts list.

Nozzles and connection seals

Nozzles and flange connections

Connect the heat exchanger to external piping. They feed the internal port passages; a pipe connection and an opening in a thin plate are different elements.

During servicing: Check connection seals, fasteners and pipe loads. Identify which connections, if any, must be disconnected for the specified opening movement.
For replacement: Port position, connection size and standard, pressure rating, material and sealing face or thread execution.

Connection liners and flange seals

A connection can have a metal or elastomer liner. Separate flange seals may also be fitted; their presence depends on the connection design.

During servicing: Inspect the wetted lining and its sealing surfaces. Distinguish a damaged connection seal from leakage at a plate gasket.
For replacement: Connection drawing, liner or gasket code, material and mounting dimensions; the nominal pipe size is only one parameter.

Protective covers and accessories

Protective sheets, insulation and port filters are optional assemblies. Identify their purpose and mounting arrangement separately from the plate pack. A port filter and its retention method must match the manufacturer’s connection design.

Cleaning and maintenance

Cleaning without opening

CIP can be considered when the deposits and cleaning chemistry permit it. Confirm compatibility with the plate, gasket and adhesive if present. A cleaning connection alone does not prove that a proposed chemical process is suitable.

Opening for inspection

A dismantled pack provides access to individual plates. Record the plate arrangement and follow the unit’s opening, cleaning and closing instructions. The assembly dimension and plate order belong to the specific equipment.

Identifying replacement parts

A matching outline is insufficient: check plate profile, port pattern and gasket groove, material grade and full part reference. Record quantity and whether a plate, gasket or complete plate pack is required.

Opening and reassembling the plate pack

Opening provides access to plates and gaskets, while the frame bars support and guide the parts. The sequence below explains the role of each assembly. Work must follow the service manual for the exact equipment, including the plate-hanging list and specified closing dimension.

Isolation and preparation

Isolate both circuits, remove pressure, bring the equipment to a safe service temperature and drain the fluids using the prescribed procedure. Check space for moving the pressure plate and handling the plates.

Record the pack arrangement

Record the equipment identification, plate order and orientation, gasket arrangement and current pack dimension. Compare these with the drawing and plate-hanging list before dismantling.

Release the compression

Check the tie-bolt threads and the guiding surfaces. Release the designated fasteners in the manufacturer’s sequence, keeping the pressure plate parallel; fastener functions and lengths can differ.

Move the pressure plate and spread the plates

Move the pressure plate along its supporting system and spread the suspended plates for inspection. Check the roller where fitted. Remove individual plates only by the method provided for that frame.

Restore the specified pack

Return plates and correctly seated gaskets in their prescribed order. Close the pack using the documented sequence and assembly dimension for the actual configuration, while maintaining alignment.

Check sealing before return to service

Carry out the manufacturer’s post-maintenance checks and the specified leak or pressure test. Test limits, circuit conditions and start-up procedure must be taken from the equipment documents.

Spare-parts identification

Start with the manufacturer, full equipment designation, serial number and parts list. Identify the assembly and its position before selecting the replacement. Appearance alone does not confirm compatibility.

Plates and cassettes

Record the part code, material, thickness, profile, port pattern, position in the pack and quantity. For a welded cassette, identify the complete cassette and its sealing arrangement.

Gaskets and rings

List plate gaskets, special end gaskets, port rings and connection seals separately. Include the code, compound, attachment method and quantity of each item.

Frame and guiding parts

Use the frame designation and drawing for the fixed and pressure plates, bars, column, roller and feet. Record the mounting interfaces and the manufacturer’s part references.

Fasteners and connections

Separate tie bolts, tightening hardware, connection studs, liners and flange seals. Confirm size, material or strength specification, execution and quantity against the equipment parts list.

Equipment catalogue

Equipment specifications are compared after the duty, materials, connections and service requirements have been defined.

Plate heat exchanger catalogue

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Prepare a specification from the data you know. Review and complete the resulting text before sending it to an engineer. This form does not send the request.

Prepare a selection brief