Lifting :- Lift from underneath if on a base (pallet).

Lift from lifting lugs (if fitted).

Lift from the top frame bar (close to the head / fixed frame plate, and support leg).

Lift from the tie bolts (in-between the frame plates, close to head frame plate)

Avoid :- Lifting from the connections.

Lifting from the follower / mobile frame plate.

Lifting from the intermediate frame plates.

Lifting from the tie bolts near to the follower / mobile frame plate.

Space :- Leave a minimum of double the width of the exchanger, either side of the unit, to allow for access to the bolts and for the easy removal of the heat transfer plates.

Leakage :- Gasket plate heat exchangers have the potential to leak. Therefore to avoid damage to plant room floor, electrical conduits, etc., we recommend that a drip tray be placed underneath the plate pack.

Safety :- If the unit is to operate above 60 Deg. C., or if it contains corrosive media, thought should be given to protecting nearby personnel. We recommend the fitting of protective screens / shields over the plate pack.

Pipe work :- We recommend the following .....

1) that the pipe work is fully supported to avoid weight/forces acting upon the unit.

2) the fitting of flexible couplings if the pipe work is subject to vibration.

3) the fitting of flexible couplings if operating over 80 Deg. C. (to absorb expansion).

4) that the pipe work is completely flushed before attaching to exchanger.

5) the fitting of suitable vents & drains.

6) the fitting of de-mountable elbow bends onto connections located on follower frame plate - this allows the follower plate to be pushed back fully along the frame bars.

Welding :- If pipe work is to be welded near to the exchanger, then do not use the unit as a grounding mechanism. Electric arcs can occur between the plates, which will damage both the plate material and the gaskets.

Isolate the exchanger before any welding is carried out.

Filtration : Unless otherwise stated, a filter mesh should be used to remove all particles greater than

0.5 m.m. diameter.

Connections: Use two wrenches when attaching unions to threaded stub connections. One to tighten the union, & the other to prevent the stub end from rotating (avoids damage to gasket inside the unit which seals against the back on the stub connection).

Use a none hardening thread sealant for best results.

Plastic Connections - avoid over-tightening. For best results use a parallel thread union with a gasket O-ring seal inside.

Flanged connections - If the connection nozzle hole is rubber lined, the liner will act as the flange gasket. Bolt the connecting flange directly to the endplate using the drilled & tapped holes provided. Tighten bolts evenly - do not over-tighten as this could strip the threads cut into the frame plate.

If stand-off, or loose backing flanges are fitted to the exchanger, a suitable gasket is required to seal the flange.

Shock :- It is essential that the exchanger is not subjected to thermal or mechanical shock as this could lead to premature gasket failure.

Start up :-

• • Fully vent system.
  • Close isolation valves between pump & exchanger.
  • Fully open valve fitted into return line from the exchanger.
  • Start the circulation pump.
  • Gradually open closed valve fitted to inlet line of exchanger.
  • Vent circuit again if necessary.
  • Repeat for other circuit(s).

Checks :- 1) Check for pressure pulses in system caused by the pumps or control valves. If found, stop operation, and rectify. Continuous pressure pulses will result in fatigue failure of the plates.

2) Visually check unit for leaks.

3) Check that all pump vents are closed to prevent air being sucked into system.

Steam :- Use only slow acting control valves and mechanisms.

Before start up :-

a) ensure that the steam control valve is fully closed.

b) ensure that the exchanger is fully drained of condense.

Start cold circuit first, then the steam side.

Open steam control valve slowly - this prevents water hammer of any condensate in the steam line, and reduces the pressure / thermal shock to the exchanger.

Ensure that the steam trap is correctly sized to allow full condensate discharge - this prevents water clogging inside the exchanger.

Warning :- Water hammer & thermal shock can damage the exchanger resulting in loss of fluid from one, or more, of the liquid circuits.

Water hammer occurs when a flowing liquid is suddenly halted. Pressure waves then travel along the pipes creating a hammering effect as they bounce off any restrictions within the pathway.

Thermal shock occurs when the bulk temperature of the exchanger is suddenly

raised or lowered. The resulting expansion or contraction of the unit can result

in leakage - sometimes quite severe from the plate pack.

Both water hammer & thermal shock can be avoided by not using fast acting

control valves, therefore, sufficient consideration should be given to protecting

the heat exchanger when designing the associated control systems.

Shut down :-

Storage :- If the unit is to taken off line for an extended period of time, then the following procedure can be followed :-

Tools Ratchet spanners and ring or open ended spanners, plus light machine oil.

Procedure :-

• • Allow unit to cool.
  • Release all pressure from inside of exchanger.
  • If fitted, remove the pipe work connected to mobile / follower frame plate, & the intermediate frame / divider plates.
  • Lightly oil tie bolt threads.
  • Undo the clamping bolts uniformly - keep the frame plates as parallel as possible during this operation.
  • Push / pull back the mobile frame plate away from plates pack & secure if necessary.
  • Separate heat transfer plates carefully, avoiding damage to gaskets.

Use gloves to handle the plates - the edges can be sharp.

Safety :- Wear gloves & eye goggles when using cleaning detergents.

Brushing :- Use nylon or other types of "soft" scrubbing brushes with detergent. Never use a metal brush, steel wool, or sand/glass paper.

Gasket glue :- Use Acetone, or other types of solvents which do not contain chlorine, to remove old gasket glue. Alternatively, use an LP gas flame, heating the reverse side of the plate. Do not use any other type of gas which may produce a "harder" flame.

Boiling water can be used with some success.

Detergents :- Consult a cleaning specialist for a suitable choice of detergent. Ensure that all detergents used are compatible with the plate and gasket material before use.

• • Oxide or chalk deposits - use 2 to 5% nitric acid solution.
  • Organic, protein containing deposits - use 2% solution of sodium hydroxide at temperature of 50 Deg. C.
  • Grease deposits - use neat kerosene, or an emulsifying agent (Jizer or Gunk).
  • Lime deposits - 10% nitric acid soak at room temperature for 10 minutes, followed by a caustic soda wash.

C.I.P. :- If the solution requires recirculation, select a flow that is as high as possible, and certainly no less than the service or product flows.

Follow the instructions as given by the detergent supplier / cleaning specialist. We suggest that for recirculated cleaning detergent methods, the fluid should be pumped through the exchanger for no less than 30 minutes.

• • Milk deposits - circulate 1.5% nitric acid at 65 Deg. C.
  • Organic or grease deposits - circulate 1.5% sodium hydroxide (NaOH) at 85 Deg. C.

Each plate is identified by the gasket arrangement, the number of port holes open, and the

angle of the pressing.

Example :- L1234 Long

L = Left hand flow (No gasket O-rings around port holes on

the left hand side of the plate).

1234 = All port holes open

Long = Thermal length of the plate (angle of the pressing).

See the Fig 3. for further examples of plate types.

A left handed plate and a right handed plate are effectively the same, except, one is rotated 180 degrees to the other.

The plates are arranged in the pack so that they alternate between left & right handed plates.

If any of the plates become damaged, these can be removed, however, in order to respect the

See Fig. 4 for gasket types.

O-rings :- Where these are fitted, the flat side of the gasket is fitted into the circular gasket groove. If

the O-ring is not flat on one side, then the thinnest part / side of the ring should be located into the gasket groove. It may be necessary to apply a small amount of gasket glue, or

"Locktite" to hold the O-ring in place whilst the plate pack is being assembled.

Plate gaskets :- If the gaskets are to be replaced, ensure that the same plate port holes remain "open" as with the old gasket. If a number of gaskets are to be replaced, and the plates have been  cleaned so the outline of the old gasket has been removed, then before attaching the gaskets, stack the plates with all of the pressing / herringbone patterns face in the same direction -  the "arrow heads" facing towards you. Fix all gaskets to the plates so that the two port holes on the right hand side of the plate are surrounded by the gasket O-rings.

Adhesive :- Chlorine free glues only, such as Pliobond 20 or 30, Bostic 1782, 3M EC 1099, and Bond Spray 77. If no instructions are provided by the adhesive manufacturer, then we suggest that a thin layer of glue is spread into the plate gasket groove, using either a narrow paint brush or a syringe. Contact adhesives (such as Pliobond 25 or 30) also require a thin layer of adhesive to be applied to the flat faced side of the gasket. Check that, once stuck, the gasket will be correctly  positioned, then fix the gasket to the plates, ensuring that all parts are seated into the gasket grooves, with no parts of the gasket stretched or "bunched". Stack the plates, and leave to set. Warm oven curing accelerates the drying process.

Snap in types :- These require no adhesive - they are located by pushing the gasket fully down into the gasket groove. The gaskets are held into place by the interference fit - narrowed portions of the gasket groove are pressed to ensure a secure fit.

Rubber liners :- On some model types, the rubber frame plate nozzle liners have an O-ring moulded into the liner itself. This moulded O-ring fits into the gasket groove in the first plate. Therefore, if new gaskets have been fitted, the O-ring portion of the gasket around the nozzle hole will have to be cut off prior to assembly back into the frame.

Plates :- These must be clean, dry, and free from oil or grease. If there are any oil deposits on the  gaskets, or on the gasket seating area, then there is a strong likelihood that the plates shall slip out of place when the unit is being tightened. If the gaskets are contaminated with dirt, or grit, then these could cause leakage.

Assembly :-

Procedure :-

• • Lightly oil tie bolt threads. Do not allow oil or grease onto the gaskets or the gasket seating faces on the back of the plates. Wet or oil contaminated plates can become misaligned during tightening. In the event, dismantle, clean, and dry all areas in contact with the gaskets.
  • Evenly tighten all bolts. We recommend the use of ratchet spanners.
  • Ensure clamping is as uniform as possible, thus keeping the frames plates parallel throughout the operation. Avoid skewing the frame plates by more than 10 m.m.
  • Tightening is complete when the distance between the inside faces of the two frame plates equals the "A" dimension as shown on the contract drawing.
  • Finally check that all bolts are in tension, and clean any spilt oil off the frame plates.
  • On completion, the unit can be pressure tested (Test pressure is stated on the name plate).

See Fig. 6 for "A" dimension example.

See Fig. 7 for suggested bolt tightening sequence.

Warning -

Do not tighten the plate pack less than the minimum tightening dimension as given on the  contract drawing. Over compression will damage both plates & gaskets. Always check that the number of plates actually fitted is correct because the tightening   dimension is calculated by use of the following equation :-

Tightening dimension = No. of plates x (plate thickness + coefficient)

The coefficients vary depending on the model type. Contact the Sales Offices for the   correct coefficient to use.

1) Nuts tight to turn :- insufficient oil on threads

2) Plates move out of alignment :- remove plates & degrease, then dry.

:- inspect plate hanging system for damage.

pressure drops :-

1) Liquid flows higher than design :- check & adjust

2) Plate channels blocked :- back flush, C.I.P., or dismantle to clean.

3) Inaccurate measurement :- check pressure gauge for accuracy

:- ensure measurement does not include any bend, valve / fitting, & pipe run losses.

4) Liquid temp. below design. :- viscous media generate higher resistance to flow at lower temperatures.

5) Media used not as per design :- the addition of glycol or other additives can increase the pressure drop.

Leakage :-

1) leakage near connection :- check condition of nozzle liner (if fitted).

:- check condition of O-ring gaskets on first plate.

:- check the flange gasket (if fitted).

:- check the stub connection back washer.

:- check the connection O-rings (if fitted)

2) cross contamination :- check all plates for cracks and / or holes.

3) leakage from plate pack :- check tightening dimension

:- check condition of the gaskets.

:- check that all gaskets are seated correctly.

For nearly all leakage problems, it shall be necessary to dismantle the unit before any attempts to rectify the fault can be made. Mark the area(s) from where the leaks are occurring before taking apart the exchanger.

"Cold leakage" - 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 should re-seal after the temperature has stabilised.

Gasket failures are generally a result of :-

1) old age

2) excessive exposure to ozone

3) high operating temperature - above the temp. limit of the material.

4) exposure to pressure surges.

5) chemical attack

6) physical damage - resulting from poor assembly practise, or damage resulting from a misaligned plate (check the hanging system at the top of the plate for distortion).

performance :-

1) plate surfaces require cleaning or de-scaling.

2) pumps or associated controls have failed.

3) plate channels blocked.

4) liquid flows not as per the design specification.

5) associated chillier / cooling tower / boiler under sized.

6) cooling water flow temperature to the exchanger is higher than design.

7) heating media temperature lower than design figures.

8) steam flow not sufficient - control valve malfunction.

9) steam trap broken or jammed - this can cause the unit to become filled with condensate.

9) plate pack has been assembly incorrectly.

10) unit running in co-current flow, instead of counter current - check with contract   drawing and alter pipe work if necessary., and check direction of pump flows.

11) air lock has developed in the plate pack.

Time interval :- once a year as a minimum.

Performance :- check temperatures and flows against commissioning data.

Plate pack :- check the tightening dimension, and look for any signs of leakage.

Nozzles :- check general condition, and for any signs of leakage.

Frame :- wipe clean all painted parts, and check surfaces for signs of damage - "touch up" if necessary.

Bolts & bars :- check for rust, and clean. Lightly coat threaded parts with molybdenum grease, or a corrosion inhibitor (ensure that no grease, etc. falls onto the plate gaskets).

To help identify the unit, it shall be necessary to quote the serial number as given on the nameplate.

Replacement parts and other information can be obtained from :-