Spare parts

Plate heat exchangers (PHE) are vital equipment on production lines in all types of industrial applications. An incident in one of the plate heat exchangers often results in the unscheduled shutdown of an entire production line with consequent losses and economic losses. For this reason, Laygo’s Technical Maintenance Service recommends and offers preventive maintenance of complete plate packages.

Preventive maintenance also corrects the loss of equipment performance due to fouling and the resulting energy losses.

Properly scheduled preventive maintenance by experts reduces the risk of unexpected production stoppages and represents significant energy savings.


Laygo’s heat exchanger gaskets are 100% compatible with the most widely used equipment on the market. Among them we can find: Alfa Laval, SPX (APV), Fischer, KELVION (Gea), Junkers, Tranter, Chester Jensen, Swep, API Schmidt Bretten, Sondex, Funke, Cipriani, AGC Engineering, Reheat, Rosenblads, Vicarb, Stork – Pierre Guerin.

LAYGO™ gaskets enjoy 1 year of guarantee for watertightness complying with the FDA standard for the following qualities: NBR, HNBR, EPDM, BUTYL-HT, FPM-B and FPM-G, while our EPDM quality exceeds USP CLASS-VI.

Storage of gaskets

When purchasing Laygo® gaskets as warehouse spare parts it is important to follow some procedures. These methods ensure that the components that make up the elastometer do not deteriorate and maximize the life of the gasket:

– Store Laygo® gaskets where the temperature does not exceed 25ºC. There will be a gradual deterioration of the physical properties of the elastometer above this temperature. If there is a choice, the optimum temperature should be 15°C. Never store the gaskets where the temperature can reach 0ºC.

– The recommended relative humidity is 70%.

– Keep gaskets away from sunlight or ultraviolet light.

– Store gaskets without tensioning them. Do not tie the gaskets tightly or store them hanging; do not add talcum powder to the gaskets which, apart from not serving to maintain them in an optimum state, considerably harm them.

– Prevent them from being near ozone sources such as welding equipment or electric motors.

– Do not store gaskets near organic solvents or acids.

– Avoid that they are stored near to heat sources (radiators, etc.).

– Keep gaskets in boxes to minimize contact with air. It is also recommended to store them in dark opaque bags; if the gaskets are in fluorelastometer quality.

– Rotate the stock so that the oldest gaskets are used first.

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Plates package

Today, manufacturers of heat exchanger plates are limited to make-to-order production and no longer stock replacement plates. This can lead to delivery times of up to 8 weeks.

At Laygo we can supply complete plate packages with gaskets according to the layout of the original equipment design. This minimizes downtime of your facility as a reconditioned package can always be available for replacement within a few hours for the next maintenance.

On the other hand, our technicians, with more than 30 years’ experience in the design of exchangers, can advise you to adapt the arrangement of plates to new service conditions or to their possible optimization.


Immediate availability of replacement plates is a priority for plate heat exchanger maintenance services. At Laygo we have a wide range of original and/or compatible plates for models and materials most often used in the market.

“In situ” sat

On-site reconditioning of PHEs

The reconditioning of a plate heat exchanger can be carried out by our specialists on site. an internal protocol is completed to determine the status of the equipment as well as its tightening dimensions before any equipment is opened. After that, the depressurised equipment is opened and the frame plates are disassembled.

The plates with mechanically fixed joints can be reconditioned “in situ”, although it is always recommended to move them to our facilities in order to carry out a deep cleaning by immersion in baths with specific cleaning agents and the subsequent inspection of the plates with penetrating liquids.

On-site reconditioning may include the following work:

  • Opening of the equipment
  • Disassembly of plates
  • Verification and possible repair of the frame.
  • Transfer of the set of plates to our facilities and return (*).
  • Assembly of the reconditioned plates in the frame.
  • Closure of the equipment and watertightness tests.

(*) or cleaning with hot or cold pressurised water.

Disassembly of plate packs and assembly of reconditioned plates

An internal protocol is completed to determine the status of the device as well as its tightening dimensions before the equipment is opened. After that, the depressurised equipment is opened and the frame plates are disassembled. The plates are properly prepared for later transport to our facilities.

Once the plates have been reconditioned in our facilities, our Specialists proceed with the assembly of the plates in the frame, the tightening of the plate package and the testing of the equipment for watertightness.

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Fluorescein Integrity Tests

Our “in situ” Fluorescein Integrity Test is a reliable procedure that allows non-contamination to be controlled by sections in the plate sets of the exchangers, without having to open them.

This procedure makes it easy to carry out preventive maintenance that complies with the latest European directives and that protects our customers from the costs and problems that a contamination of their products would entail.

It is only necessary to interrupt production for a few hours, as opposed to the various days required by classic procedures.

This procedure makes it possible to reliably control the absence of contamination by means of fluorescein circulating under pressure through one of the circuits and water from the low pressure network circulating through the second circuit. Samples are taken and monitored by means of a fluorometer (unit of measurement in PPT) in order to check the stabilisation or evolution of the water.

This allows the test to be carried out under real conditions of use and to prevent any risk of damage to the plate after the control, for example during assembly.

For one-step equipment, gas detection systems (Nitron 5 or hydrogen) can also be used, although for correct measurement, the heat exchangers should have previously been emptied of all liquids, even below the level of the lower nozzles. After several tests and empirical tests carried out in collaboration with external companies, Laygo has decided not to recommend gas inspection methods in the case of multi-step equipment.

Reconditioning at our facilities

PHE – Plate Heat Exchanger

An internal protocol is completed to determine the state of the equipment as well as its tightening dimensions after the reception of the equipment at our facilities and before proceeding to its opening. After that, the PHE is opened, the plates are disassembled and the frame is checked. The procedure for reconditioning plates in our facilities is described below.

Once the plates have been reconditioned in our facilities, our Specialists proceed with the assembly of the plates in the frame, the tightening of the plate package and the testing of the equipment for watertightness.

The PHE is properly prepared for subsequent return transport.


We have all the specific means and procedures to clean, inspect and recondition heat exchanger plates effectively, cost-effectively and 100% reliably at our facilities. The usual plate reconditioning procedures are described in more detail in the following sections: Entry Inspection, Cleaning, Inspection of Penetrating Liquids, Assembly of New Gaskets (Glued), Assembly of New Gaskets (Clip – Mechanical Fixation) and Final Inspection and Grouping of Plates.

Entry inspection

After the reception of the plates or the equipment at our facilities the protocol for entry (internal) is completed, which takes into account all the technical details of the equipment as well as of the contracted works.


The disassembly of the gaskets on the plates is carried out by applying heat from the back of the cradle or using liquid nitrogen. Heavily soiled plates are first cleaned with hot or cold pressurised water.

Hot soda baths are used to remove organic dirt and glue residues (not for titanium). Once the plates have been rinsed in water, they are immersed in baths with strippers (acids) and cleaned again using pressurised water.

Baths with hot pickling agents (acids) are used directly to remove inorganic dirt. The exposure times are adjusted and the process is repeated after the rinsing bath depending on the degree of soiling.

It is of vital importance to clean the plates in depth and at the same time avoid a chemical attack of the materials (shading plates).

After cleaning, the plates are dried. Drying time can be reduced by using an industrial kiln.

Inspection with penetrating liquids

The inspection of plates by our SAT Department is always for 100% of the plates. Unlike other maintenance companies, we inspect each plate separately, spraying one side with penetrating liquid. We use fluorescent penetrants because of their greater sensitivity. The fluorescent liquid penetrates any discontinuity that may exist due to the phenomenon of capillarity. After a certain exposure time they are inspected with the help of an ultraviolet light lamp (black light). This visual inspection operation in a “dark room” is carried out by specialised technicians to guarantee maximum reliability.

In certain cases (special plates or heavy wear without perforation) we also use coloured penetrating liquids (red) and developer (white) or combined penetrating liquids (colour + fluorescent). When no perforations are detected, but if a marked wear of the contact points is observed, one of the faces is sprayed with the red dye and after a certain time, this face of the plate is cleaned and sprayed with the developer white to detect microcracks or fissures (not complete).

These areas are adequately marked for possible visual inspection or by means of an electron microscope in the case of perforations, micropores and microcracks.

All defective plates and therefore “unfit” for service (perforated and/or bent) are packed, properly identified and returned to the customer.

The plates that are in good condition and “suitable” for service are cleaned on both sides with pressurized water to remove any remaining penetrating liquid. After drying, they go on to the next reconditioning process, the assembly of the new gaskets.

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Assembly of new (glued) gaskets

The cradles of the plates (gasket housing) are visually inspected in detail before assembling the new gaskets. Except in certain isolated cases (depending on the plate) these deformations are not corrected because the material would no longer offer sufficient mechanical strength. A rejection is already carried out due to marked deformations of the cradles during the protocol of reception of the materials.

The cradles must be perfectly clean and degreased before proceeding with the gluing operations. Specific contact adhesives or bi-component adhesives are used (both FDA, for food or pharmaceutical applications) depending on the plate model and the application. In both cases the adhesive is spread over the appropriate area of the plate (and depending on the adhesive, also over the gasket) using a brush. After the gasket is correctly put in position, the plate is placed in a frame for the later tightening of a certain set/number of plates. It is simply dried or cured inside an industrial oven depending on the adhesive used.

Once this process is finished, all the plates are inspected again (one by one) to eliminate possible remains or excess of adhesive.

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Assembly of new gaskets (CLIP – Mechanical Fastening)

In the case of mechanically fixed gaskets, the assembly of these is carried out according to the “Clip” system of the plate. Sometimes and depending on the degree of deformation of the plates, the position of the gasket is reinforced by means of contact adhesive points (FDA). This last method, always with prior authorisation from the customer.

Final inspection and grouping of plates

The reconditioned plates with new gaskets are placed in the packs (or assembled) following the correct order and arrangement according to the plate diagram.

In the case of complete equipment, the reconditioned plates are assembled in the frame to later tighten the set to its closing level and carry out the corresponding watertightness tests. After the reconditioning work and depending on the state of the plates or the equipment, Laygo can draw up a Technical Report of the intervention.