FAQ Pillow Plate

Figure: FAQ on Pillow plate

1. Definitions

Question 1: What is a pillow plate (pillowplate)?

Answer 1: A pillow plate is a heat exchanger made from two metal sheets laser-welded in a pattern and then inflated so a heating or cooling medium can flow inside.

• After inflation the surface looks like a pillow; that is where the name comes from.
• On keppelslaserwelding.com the term means a laser-welded, inflated plate — not a pre pressed dimple sheet.
• The same product family is also called dimple jacket, dimple plate, thermo plate, thermplate, laserplate or laser plate.
• Keppels Laser Welding builds the laser welding machines that make them and can also supply finished pillow plates.
• The weld pattern sets the flow path; the inflation sets the channel height.

Question 2: What is a dimple jacket / dimple plate?

Answer 2: Dimple jacket is the older trade name for a heating or cooling jacket on a tank; in many US shops it already means a laser-welded pillow plate.

• Pre-formed dimple is a different route: a pressed sheet welded onto a finished tank by hand.
• Always ask which process the customer means before you quote pressure or price.
• A laser-welded dimple jacket / pillow plate is welded flat as two sheets and inflated after welding.
• Typical published limit for classic pre-formed dimple is about 4–5 bar (60–70 psi).
• Laser-welded pillow plates can be designed for higher working pressure (400 bar) when the pattern and thickness allow it.

Question 3: Is a pillow plate the same as a dimple jacket?

Answer 3: Same job — heat transfer on a tank or plate — but not always the same production route.

• Sales language often mixes pillow plate and dimple jacket.
• Laser-welded pillow plates allow free CAD patterns and welding from one side.
• Classic pre-formed dimple is pressed first and usually hand-welded onto a finished vessel.
• Engineering decisions must follow the actual geometry, not the catalogue name.
• In a US enquiry, dimple jacket may already mean laser-welded pillow plate — confirm it.

Question 4: What is the difference between a laser-welded pillow plate and a pre-formed dimple plate?

Answer 4: A laser-welded pillow plate is welded flat as two sheets and then inflated; a pre-formed dimple plate is pressed first and then welded onto the vessel, usually by hand.

• Pre-formed dimple: typical published pressure about 4–5 bar (60–70 psi).
• Laser pillow plate: free CAD pattern, one-side welding, optional film on the product face.
• Laser plates can be designed for higher working pressure than classic dimple when the pattern is proven.
• The tank inside is not electrode-marked with laser welding.
• Do not transfer a pre-formed dimple pressure number onto a laser pillow plate, or the other way around.

Question 5: What does single embossed vs double embossed mean?

Answer 5: Single embossed is a thin sheet on a thick base so only the thin sheet inflates; double embossed is two equal (or similar) sheets that both form the channel.

• Single embossed is the usual tank-jacket / dimple jacket construction.
• Common single-embossed pairs: 0.8 mm on 2.0 mm; 1.0 mm on 2.5 mm; 1.2–1.5 mm on 4–15 mm; 2.0 mm on 5–15 mm.
• Milk tanks often use 0.8 + 2.0 mm with protection film on the base.
• Double embossed pairs: 0.8+0.8, 1.0+1.0, 1.2+1.2, 1.5+1.5, 2.0+2.0 mm.
• Double embossed is typical for falling-film chillers, ice banks, refrigeration plates and immersion banks.

Question 6: What is a thermo plate / laser plate?

Answer 6: Thermo plate, thermoplate, thermplate, Laser Plate and Temp-Plate are brand or trade names for the same physics as a pillow plate: two sheets welded in a pattern and inflated.

• The name does not tell you the pressure, pattern or production method.
• Ask whether the plate is laser-welded or pre-formed dimple.
• Ask whether it is single embossed or double embossed.
• Keppels uses pillow plate as the canonical term on keppelslaserwelding.com.
• Application names (register, falling film, ice bank) sit on top of the same construction.

Question 7: What is a register plate / falling-film plate / ice-bank plate?

Answer 7: Register, falling-film and ice-bank plates are application names for a pillow plate with a pattern and connections suited to that application.

• A falling-film plate is usually double embossed, often 1.0+1.0 mm 304L.
• Published falling-film example: max working pressure 19 bar, test 25 bar, about 2–2.5 liters medium per m².
• Ice-bank plates freeze a water inventory on the plate surface for later cooling.
• Register plates are immersion or pack plates, not tank jackets.
• Keppels sizes connections and headers and can supply designs and plates or complete falling-film and ice-bank systems.

Question 8: What is the difference between a pillow-plate tank jacket and a pillow-plate heat exchanger (plate pack in a shell)?

Answer 8: A tank jacket is usually a single-embossed pillow plate on a vessel wall or bottom; a pillow-plate heat exchanger pack is a set of double-embossed plates with product between them.

• The jacket heats or cools the tank contents through the vessel wall.
• The pack is itself the exchanger — product flows between plates, medium inside the pillows.
• Jacket design follows tank diameter, rolling sequence and vessel code.
• Pack design follows header flow, hold-up and two-phase behavior if it is a refrigerant.
• Keppels calculates both duties for tank jacket or heat-exchanger.

2. How the product works

Question 9: How is a pillow plate made?

Answer 9: Two sheets are laser-welded flat in a CAD pattern, inspected, then inflated to form the flow channel.

• The customer drawing becomes a flat welding layout (CAD/DXF).
• Keppels generates a machine program from that layout in a few minutes.
• Sheets are cleaned, clamped and laser-welded from one side on a K1500 or K2000 pillow plate machine.
• Cutting can be before or after welding.
• Inflation, connections and finishing are separate workshop steps — the welding machine does not inflate the plate.

Question 10: Why is the plate inflated after welding?

Answer 10: Inflation creates the flow channel; without it the two sheets stay flat and no medium can pass.

• Inflation pressure is a forming parameter, not the working pressure.
• The pressure is set so later working and test pressure do not reshape the pillow.
• Chain: working pressure < test pressure < inflation pressure < burst pressure.
• Heads are often inflated after they are installed on the vessel.
• An inflation table keeps flat plates flat during forming.

Question 11: At what pressure is it inflated, and how does that relate to working pressure?

Answer 11: They are not the same: production inflation for ordinary patterns is typically 15–250 bar (220–3,630 psi) with water; working pressure is set later by PED or ASME plus a burst panel.

• Never treat inflation pressure as allowable working pressure.
• Special patterns can sit outside the 15–250 bar band.
• A plate can need a high forming pressure and still have a modest working pressure.
• Never burst-test with gas.
• Keppels trains inflation procedures with the laser welding machine; the machine itself does not inflate.

Question 12: How does the medium flow through a pillow plate?

Answer 12: Medium enters at one connection, weaves around the weld spots and leaves at the other.

• Spots carry pressure; borders close the vessel; flow lines steer channels.
• Steam plates usually have no flow lines; condensate must still reach the outlet.
• Corners should be wider than the channel so they do not choke the flow and gives a pressure drop.
• Hold-up is small compared with a conventional double jacket.
• Headers and port place belong in the design from the start, not as an afterthought.

Question 13: Why does the weld pattern create turbulence / better heat transfer?

Answer 13: The weld spots break up a plain gap into a weaving channel, which raises turbulence and improves heat transfer compared with an empty double jacket.

• K-value is not a material constant; geometry and velocity matter as much as steel grade.
• Tighter pitch changes both pressure capability and flow.
• Textbook flat-plate k-values are only a start.
• Keppels calculates Q = A × k × LMTD for the actual duty.
• Fouling and two-phase flow can dominate k more than the spot layout.

Question 14: What is the difference between a spot pattern, line welds and flow channels?

Answer 14: Spots carry pressure, line welds (borders) close the vessel, and flow channels / flow lines steer the medium.

• A pillow plate laser welding machine welds spots, lines and borders in one program / one product pass.
• Steam plates often omit flow lines so condensate is not trapped.
• Headers and oval pitches are used when a water film must stay even (falling film).
• Diamond/staggered layouts are generally stiffer than square / inline.
• There is no single standard pattern for every duty.

Question 15: Does the back of the weld still need grinding or cleaning?

Answer 15: No — laser welding is from one side, so you do not grind electrode marks off the product face the way resistance welding requires.

• The tank inside is not electrode-marked.
• Protection film can stay on a single-embossed base during welding.
• That is a main reason shops move from resistance spot to a laser welding machine.
• Pickling or polish later follows the vessel specification, not the laser recipe.
• Inspect the weld face before inflation; do not hide a defect under forming.

Question 16: Does the product side of a tank stay smooth with laser welding?

Answer 16: Yes — laser welding from one side leaves the product face unmarked, so a single-embossed base can keep mill finish or film.

• This helps food tanks (milk/BMC, wine, beer) where the inside must stay clean.
• FDA / 3-A / EHEDG are still vessel rules; the laser only helps the surface.
• Resistance welding marks both faces and cannot keep film.
• A handheld laser welder is not a substitute for this one-side CNC process.
• Confirm film type and base thickness before you weld.

Question 17: Do you roll the plate before or after inflation for tank jackets?

Answer 17: Both sequences exist: weld flat then inflate then roll, or weld flat then roll uninflated, build the tank, and inflate after assembly.

• Inflate-after-assembly avoids crushing pillows in the roll.
• Inflate-then-roll needs a pattern strong enough for roll shear.
• Published practice includes roll radii above about 100 mm (3.9 in). Diameter 100 mm needs special tools.
• Heavy rolling often wants stronger circles (sometimes double-welded circles).
• Tank heads and cones follow the second idea: form first, inflate after install.

3. Design: pressure, thickness, pattern

Question 18: Which sheet thickness belongs with which working pressure?

Answer 18: Thickness is only one input; pattern, material and temperature set the rest — there is no single thickness-to-pressure table you can copy.

• Top sheet often 0.8–2.0 mm (0.031–0.079 in).
• About 0.8 mm top for milk tanks; 1.0–2.0 mm for general tanks and falling film; 1.2–1.5 mm for steam and thermal oil.
• A 1.0 mm top has a possible tested burst pressure by Keppels of 180 bar (2,610 psi).
• A 2.5 mm sheet can move toward 400–700 bar burst in Keppels produces samples.
• Prove the pattern on a burst panel with the properties of the real product.

Question 19: What is a typical working pressure for water/glycol, NH3/Freon, CO2 and steam?

Answer 19: Published Keppels starting examples: water/glycol/oil about 1–5 bar; NH3/Freon about 19 bar at 20 °C standstill; CO2 about 120 bar; steam about -0.5 to 30 bar.

• These are application examples, not universal allowable pressures.
• NH3/Freon 19 bar (280 psi) is a common standstill figure, not a license to skip PED/ASME.
• CO2 sits much higher because of the saturation curve — about 90-120 bar (1,740 psi) in the published example.
• Steam needs condensate removal and a robust top sheet.
• Keppels sets working pressure from the duty, the burst panel and the applicable code.

Question 20: What burst pressure / test pressure is usual?

Answer 20: Test pressure sits above working pressure and below inflation and burst; a published high burst example is about 180 bar at 1.0 mm top sheet.

• Chain: working < test < inflation < burst.
• Falling-film published examples for Freon or NH3: work 19 bar, test 25 bar.
• If the panel fails at a border or header, you tested the design, not the pattern.
• Useful result: parent sheet fails, weld holds.
• Never burst-test with gas or air.

Question 21: How do I choose the weld pattern (pitch, spot diameter)?

Answer 21: Tighter pitch and larger weld circles raise pressure and lower pillow height; choose the pattern for the duty, not from a catalogue default.

• Diamond/staggered layouts are generally stiffer than square.
• A geometrically perfect diamond can channel during inflation.
• Oval pitches keep a falling-film water sheet more even.
• Steam plates usually skip flow lines.
• Keppels know-how sits in the pattern generator and available as experience.

Question 22: What is the difference between a staggered (diamond) and an inline pattern?

Answer 22: A staggered diamond layout is generally stiffer than an inline square pattern of the same pitch.

• Stiffer pattern → higher pressure capability and less oil-canning for the same thickness.
• Inline can be simpler to program and to roll.
• A perfect diamond can channel during inflation if the path is too regular.
• Falling film often uses application specific patterns.
• There is no single standard pattern for every pillow plate duty.

Question 23: What is the maximum sheet thickness (base + top) that can be welded?

Answer 23: Combined base + top on Keppels pillow plate machines is up to about 30 mm (1.18 in).

• Single embossed often pairs a thin top (0.8–2.0 mm) with a thick base.
• Hydraulic multi-point clamping is there for that thickness range.
• Do not copy a 0.8+0.8 mm program onto a 2+15 mm stack.
• New thickness pairs still need a weld and inflation trial.
• Width limit is 2000 mm, independent of thickness but available material width.

Question 24: How large may one pillow plate be?

Answer 24: Width is a machine limit 2000 mm (K2000); length is a handling and shop-floor limit, not a laser limit.

• Wider jackets are split into panels.
• A full cylinder is normally several panels at 1500 or 2000 mm.
• Heads and cones are welded in the flat, then formed.
• Ask for handling, rolling and inflation-table size when the plate is long.
• Keppels quotes panel layout with the machine or the plate order.

Question 25: What if the plate is wider than the machine width (1500 / 2000 mm)?

Answer 25: Split the jacket into panels at 1500 or 2000 mm and join them on the vessel.

• Do not expect one laser pass across a 3 m-wide sheet on these machines.
• Plan circumferential seams and header strategy at design stage.
• Each panel is still one pillow plate with its own borders and ports.
• Falling-film standard widths in published data include 1000, 1500 and 2900 mm — the 2900×1500 mm plate is welded in one pass on a K1500 or K2000.
• Keppels helps with the panel split when you send the tank drawing.

Question 26: Single embossed: how thick should the base sheet be relative to the top sheet?

Answer 26: The base is the structural sheet and is thicker than the inflating top; common pairs start at 0.8 on 2.0 mm and run up to 2.0 mm on 5–15 mm.

• Milk / BMC Bulk Milk Cooler: often 0.8 + 2.0 mm with film on the base.
• Heavier tanks and steam: thicker base and a 1.2–2.0 mm top.
• Do not over-inflate or the thick side dishes.
• Unequal thickness is normal for single-embossed pillow plates.
• The base thickness also follows vessel design, not only the jacket.

Question 27: Double embossed: when do you use two equal thicknesses?

Answer 27: Use two equal sheets when the plate itself is the heat-transfer surface — refrigeration, falling film, ice banks, registers.

• Common pairs: 0.8+0.8 through 2.0+2.0 mm.
• Published falling-film standard: 1.0+1.0 mm 304L.
• Equal thickness keeps both faces inflating evenly.
• Working pressure still depends on pattern, not only on 1+1 mm.
• Do not treat a double-embossed pack as a tank jacket.

Question 28: How do you calculate heat transfer / LMTD / required area?

Answer 28: Start from Q = A × k × LMTD, then let Keppels calculate k and area for the actual duty — k is a  process specific heat transfer constant.

• Q is duty, A is area, LMTD is the log mean temperature difference.
• k depends on velocity, geometry, fouling, wall and both fluids/gasses.
• Textbook flat-plate k-values are only a start.
• Refrigerant plates are two-phase designs, not water jackets.
• Public pages explain the method; the customer calculation is done by Keppels.

Question 29: Is there a standard design method, or is it application-specific?

Answer 29: It is application-specific; there is no single standard pattern or k-value for every pillow plate.

• Water jackets, NH3 falling film, CO2 plates and steam jackets are different designs.
• Food, chemical and HVAC-chilled-water duties change fouling, CIP and material.
• Burst panels prove a pattern; they do not replace the vessel code.
• Spreadsheets cover most first estimates; CFD is for special applications.
• Send Keppels the duty data rather than copying a plate.

4. Materials

Question 30: Which materials can you laser-weld into a pillow plate? (304L, 316L, 254SMO, titanium, copper, aluminum)

Answer 30: Daily work is austenitic stainless from 304L through 254SMO; duplex and carbon steel are possible; copper, aluminum and titanium have been welded on Keppels IPG fiber machines but need qualified parameters.

• 304L / 1.4307 is the falling-film workhorse.
• 316L and 254SMO follow corrosion duty.
• Do not copy a 304 procedure onto copper or titanium.
• New alloys still need a weld and inflation trial.
• You cannot claim “all metals standard” on a pillow plate laser welding machine.

Question 31: Can you weld dissimilar materials or unequal thicknesses?

Answer 31: Unequal thickness is normal for single-embossed plates; unequal materials are possible only after a qualified trial.

• 8 mm top on 2.0 mm base is everyday single-embossed practice.
• Do not assume 304-to-316 or stainless-to-copper is a stock recipe.
• Thermal expansion and weld metallurgy change with dissimilar metals.
• Inflation behavior changes when one sheet is much stronger than the other.
• Ask Keppels for a trial before you apply a dissimilar pair.

Question 32: What is difficult about titanium / copper / aluminum?

Answer 32: Each needs its own parameters: titanium needs oxygen-free shielding, copper is highly conductive and thin, aluminum is alloy- and oxide-sensitive.

• Do not copy a 304 program onto these metals.
• Copper published top gauges sit about 0.1–1.5 mm.
• Titanium inflation and cleanliness rules are stricter than stainless.
• Aluminum alloy and surface condition matter as much as thickness.
• Keppels has welded all three on IPG fiber machines; production still starts with a trial.

Question 33: Is a weld and inflation trial needed per material?

Answer 33: Yes for a new alloy, a new thickness pair or a new production condition — a material name is not a welding qualification.

• 304L 1.0+1.0 mm falling film is established practice.
• Copper, aluminum and titanium always start with a trial.
• Burst-test the representative panel, not only a coupon.
• Keep the trial with the WPS/PQR file if the vessel is PED or ASME.
• Keppels treats a new stack as process development, not as a catalogue tick-box.

Question 34: Which thicknesses are realistic for copper?

Answer 34: Published copper tops sit in the thin-sheet range, about 0.1 to 1.5 mm (0.004–0.059 in).

• Copper is not a drop-in for 1.0 mm stainless.
• Conductivity helps heat transfer but makes welding and inflation different.
• Qualify the exact alloy and temper.
• Do not promise vessel-code copper jackets without a trial panel.
• Keppels has produced copper pillow plates on IPG fiber machines.

5. Applications

Question 35: Where are pillow plates used?

Answer 35: Anywhere a compact metal heat-transfer surface can sit on a tank, in a pack or in a process machine — jackets, falling film, ice banks, bulk solids, clamp-on panels.

• Single embossed: beer, wine, milk/BMC, chocolate, process, fermenting, truck tanks, troughs, oven walls, freeze-dry plates.
• Double embossed: ice water 0.5 °C, glycol, Freon, ammonia R717, CO2, falling-film chillers, ice banks, immersion registers.
• Also heat recovery from air or wastewater and battery cold plates.
• Keppels calculates the pillow plate area for the actual duty.
• A pillow plate can be the jacket or the exchanger itself.

Question 36: How do you apply pillow plates on milk tanks / BMC, wine and beer tanks, process vessels?

Answer 36: Use a single-embossed pillow plate / dimple jacket on the shell and often the bottom, with film on the product-side base and a pattern designed for the tank pressure and CIP.

• Milk / BMC often 0.8 + 2.0 mm.
• Laser welding keeps the product face unmarked.
• Roll after weld, or inflate after the vessel is built — both are used.
• Food rules (FDA / 3-A / EHEDG) stay with the tank builder.
• Keppels sizes the jacket area from the cooling or heating duty.

Question 37: How do ice banks and falling-film chillers work with pillow plates?

Answer 37: Double-embossed pillow plates form the cold surface: falling film runs a thin product film down the plate; an ice bank freezes a water inventory on the plate for later cooling.

• Published falling-film chillers: 50 – 1200 kW duty.
• About 2–2.5 litres medium per m².
• The water film runs over the cold plate.
• These are two-phase refrigerant designs, not water jackets.
• Keppels can supply plates or complete falling-film and ice-bank systems.

Question 38: What is a bulk-solid heat exchanger with pillow plates?

Answer 38: A bulk-solid heat exchanger uses pillow plates as the walls or internals that a powder, granule or grain slides against, so the solid is heated or cooled without a jacketed tank.

• Plates can be vertical banks, hoppers or vibratory-feeder decks.
• Duty is conduction into a moving solid, not a tank liquid.
• Pattern and flatness matter because the solid must keep contact.
• Hold-up on the medium side stays small.
• Keppels calculates this BSHE duty with the own developed BSHE heat transfer calculation software.

Question 39: When immersion / submerged plates vs tank jackets?

Answer 39: Use a tank jacket when the vessel wall is the heat-transfer surface; use immersion / register plates when you need extra area inside the liquid or when the tank wall cannot take a jacket.

• Jackets suit beer, wine, milk and process tanks.
• Immersion registers suit ice water, baths and retrofit cooling.
• A jacket is usually single embossed; a register is usually double embossed.
• CIP and dead legs change with internal plates.
• Keppels sizes both; do not swap the constructions without a new calculation.

Question 40: Can a pillow plate itself be the structure?

Answer 40: Yes — a double-embossed pillow plate can be the wall of a trough, hopper, freeze-dry shelf or pack, not only a jacket on a separate tank.

• The plate then carries both pressure and structure.
• Edges, frames and supports must be designed with the pillows.
• Do not treat a self-supporting plate as a thin clamp-on jacket.
• Burst and deflection belong in that design.
• Keppels flags this when the drawing shows the plate as the vessel.

Question 41: Pillow plate vs half-pipe coil vs double jacket vs shell-and-tube?

Answer 41: Laser pillow plate: free pattern, low hold-up, one-side weld, higher pressure when designed for it; half-pipe is heavy and slow; a double jacket has large hold-up; pre-formed dimple is typically 4–5 bar; shell-and-tube is a separate exchanger, not a jacket.

• Half-pipe: line-wise coverage, more welding hours.
• Double jacket: simple but slow to heat and hard to drain.
• Pre-formed dimple: hand weld on a finished tank.
• Pillow plate / dimple jacket: CAD pattern and small volume.
• Pick by duty, pressure, hold-up and shop skill — not by habit.

Question 42: Can you make conical heads, dished heads or cylinder + jacket in one plate?

Answer 42: Weld in the flat, leave an unwelded band if the head must be pressed, form, install, then inflate — a full cylinder is normally several panels, not one giant plate.

• Heads and cones follow the form-then-inflate sequence.
• Machine width is 2000 mm. Keppels Laser Welding as build a special 2500 mm width pillow plate machine.
• A trough can combine straight walls and a rounded bottom.
• Published roll radii start above about 100 mm.
• Keppels trains this sequence with the laser welding machine after installation on your site..

Question 43: Can you put a clamp-on jacket on an existing tank?

Answer 43: Yes — a pillow plate can be built as an external clamp-on or panel jacket when you cannot integrate it into the vessel wall.

• Contact quality and insulation decide the real k.
• Pressure stays inside the pillow plate, not in a new vessel jacket space.
• Useful for retrofit and for tanks you must not cut.
• Still design ports, drains and thermal expansion.
• Keppels calculates the area knowing it is clamp-on, not integral.

Question 44: Do food vs chemical vs HVAC chilled-water designs differ?

Answer 44: Yes — food cares about the unmarked product face and CIP; chemical cares about alloy and corrosion; HVAC chilled water is usually a modest-pressure water/glycol jacket.

• Food: film on the base, 304L/316L, vessel hygiene rules.
• Chemical: 316L to 254SMO or better, design pressure and medium compatibility.
• HVAC: 1–5 bar water/glycol examples, fouling and pump ΔP.
• Refrigerant HVAC (NH3, CO2) is not “chilled water”.
• Do not copy one industry’s pattern onto another.

Question 45: Can the jacket run thermal oil at high temperature?

Answer 45: Yes, thermal-oil jackets are done; published starting tops are about 1.2–1.5 mm and the design must follow oil temperature, pressure and expansion, not a water-jacket pattern.

• Thermal oil is not water — viscosity and film coefficients change k.
• Metal temperature and differential expansion matter on a thick base.
• Thermal oil can be used to 320 degrees Celsius, oil temperature, the process can be hotter.
• Working pressure example band for steam is 0.5 to under 30 bar; oil is 3 bar.
• Send Keppels the oil type, temperatures and allowable ΔP.

6. Thermo-hydraulics

Question 46: What is the pressure drop ΔP in the channel?

Answer 46: ΔP depends on pillow height, path length, corners, headers, connections and velocity — it is a design result, not a catalogue constant.

• Corners should be wider than the channel to reduce pressure drop.
• Small hold-up is good only if velocity stays in range.
• Headers can dominate or reduce ΔP on wide plates.
• Spreadsheets cover most first estimates.
• Keppels includes allowable pressure drop in the customer application calculation.

Question 47: What is the hold-up volume / contents of the jacket?

Answer 47: Hold-up is pillow height times free area and is much smaller than a conventional double jacket; a published falling-film figure is about 2–2.5 liters of medium per m².

• Small volume means faster response and a smaller pump inventory.
• It also means you must keep velocity high enough, Keppels has the know-how.
• Steam and refrigerant hold-up follow two-phase rules.
• Drain ability of the pillow is a connection design issue.
• Ask Keppels for hold-up when you size expansion vessels or refrigerant charge.

Question 48: How do fouling, CIP and dead corners in the pattern work?

Answer 48: Product-side CIP is a tank problem; the pillow side needs drainable connections; dead corners in the pattern are avoided by wider corners and sensible flow lines.

• Fouling belongs in k, not as an afterthought.
• Steam needs condensate removal so the top sheet does not waterlog.
• Refrigerant oil logging is a two-phase layout issue.
• Do not promise CIP of the pillow plate without drain points.
• Food tanks still follow 3-A / EHEDG on the product face.

Question 49: How do condensation / evaporation work in the jacket (steam, NH3)?

Answer 49: Steam and NH3 jackets are two-phase: vapor must reach the surface and liquid must leave — they are not water jackets with a different name.

• Steam plates usually have no flow lines so condensate is not trapped.
• NH3 falling film uses an oval pattern in the published Keppels data.
• Robust top sheet for steam and thermal oil.
• Working-pressure examples: steam -0.5 to under 30 bar; NH3 about 19 bar standstill.
• Keppels designs these as two-phase duties.

Question 50: Which glycol concentration, freeze point and pump selection belong with that?

Answer 50: Specify glycol as a mixture with freeze point and concentration — not as the word “glycol” — then size the pump on viscosity, flow and ΔP of that mix.

• Water/glycol jackets often sit in the 1–5 bar example band.
• Viscosity at the cold end drives pump power more than density.
• Hold-up is small, so inventory is small, but velocity still matters.
• Do not use an NH3 plate design for glycol water.
• Send Keppels the mix, freeze point and allowable ΔP.

Question 51: When is CFD needed, and when is a spreadsheet enough?

Answer 51: A spreadsheet covers most first estimates of Q = A × k × LMTD and ΔP; CFD is for awkward headers/plates, misdistribution or unusual geometries.

• Uniform jackets and standard falling-film plates rarely start in CFD.
• Wide plates with short headers are the usual CFD case.
• CFD does not replace a burst panel or a vessel code.
• Keppels decides this on the actual drawing.
• Do not buy CFD when the duty is a textbook milk-tank jacket.

7. Inflation and finishing

Question 52: Does the machine also inflate the plate, or only weld?

Answer 52: The laser welding machine welds only; inflation is a separate forming step. Keppels trains inflation and can specify and deliver pumps and tables separately.

• Common production inflation: water, 15–250 bar for ordinary patterns.
• Inflation benches and pumps are options, not the gantry.
• Tank heads are inflated after install.
• Liquid is the default for safety at high pressure.
• A “complete system” quote must list inflation gear if you want it in the crate.

Question 53: Water vs oil vs compressed air for inflation?

Answer 53: Water (or another liquid) is the normal production medium; gas is only used when the circuit must stay dry; oil is uncommon and must be justified.

• Liquid stores far less energy than gas at the same pressure, so no explosion if burst.
• Gas is sometimes used on refrigerant plates to keep the circuit dry.
• Never burst-test with gas.
• Compressed air is not a substitute for a 100-bar water pump.
• Keppels trains you the safe medium for the plate you are making.

Question 54: Is a mould / inflation bed needed for flatness?

Answer 54: An inflation table (bed) keeps flat plates flat; it is recommended for panels that must stay flat and is specified separately from the welding machine.

• Without a bed, a free plate can dish or oil-can.
• After inflation a light roll or a 45°/90° edge fold can take remaining oil-canning out.
• Do not over-inflate a single-embossed base.
• Heads inflated on the vessel use the vessel itself as the form.
• Ask for the table in the machine quotation if you make flat packs.

Question 55: How do you handle shrink, straightening and rolling to a tank shell?

Answer 55: The welded top sheet shortens a little along the weld path; operators mark expected rows and correct transport, then roll with a pattern that can take the shear.

• Many layouts add a 40–50 mm tear-off clamp strip so the clamps hold the top sheet.
• Heavy rolling wants stronger circles, double or tripple welded pillow plate laser circles.
• If the rolling is too aggressive the welds can tear.
• Two sequences: inflate then roll, or roll then inflate after assembly.
• Radii above about 100 mm are published practice. Smaller ask Keppels experience.

Question 56: Do you weld inlets and outlets before or after inflation?

Answer 56: A small inflation nipple is often welded before inflation; the process connection, castle-piece or header is finished after the pillow has its shape.

• The cavity can also be reached through the base.
• Headers are cut to the inflated shape and welded on.
• Castle-piece and header detail is workshop practice, not a laser-parameter setting.
• Do not put a finished sanitary ferrule on a flat sheet and then expect it to sit after inflation.
• Keppels trains the connection sequence with the machine.

Question 57: Passivation, pickling, electro polishing — when?

Answer 57: After forming and welding of connections, to the vessel specification — not as part of the laser recipe.

• Food tanks often pickle and passivate the product face.
• Electro polish is a vessel/customer choice.
• Do not pickle as a way to hide a bad weld.
• Film on a single-embossed base may change when you finish the tank.
• Codes (FDA / 3-A / EHEDG) sit with the tank builder.

8. Quality and failure

Question 58: What are typical weld faults (incomplete fusion, pores, leaking spots)?

Answer 58: Large faults come from dirt, gap or poor clamp; small faults are pinholes, heat still in a tight loop, and unstable start/stop.

• Inspect while the plate is still flat.
• Incomplete fusion and porosity show up as leakers at inflation or in a dunk test.
• A leaking spot before inflation is easier to repair than after.
• Stainless reflection and dirty sheet are process issues before they are laser issues.
• Parent sheet should fail in a burst test; the weld should hold.

Question 59: How do you detect a leaking spot before inflation?

Answer 59: Inspect visually while the plate is flat, then use water hold, dunk or soap on a low-pressure check before full inflation.

• Helium if the later duty is vacuum-tight.
• Defects are easier to grind and re-weld before the pillow exists.
• Do not skip the pre-inflation look because “inflation will show it”.
• Clamp marks and start/stop points are the first places to look.
• Keppels trains this quality check with the machine.

Question 60: What if the plate tears during inflation?

Answer 60: Stop, depressurize with liquid still in the system, and treat it as a process or design fault — not as a license to push more pressure.

• If the parent sheet tore and the welds held, you found the pattern limit.
• If a border or header opened, you tested the design, not the pattern.
• Dirt, gap or a weak circle row are common shop causes.
• Never continue a gas inflation after a tear.
• Repair on a depressurized plate; do not weld on trapped pressure.

Question 61: How do you control residual stress, distortion and oil-canning?

Answer 61: Clamp well, keep the pattern stiff enough, use an inflation table for flat work, and take remaining oil-canning out with a light roll or an edge fold.

• A 40–50 mm extra clamp strip helps hold the top sheet.
• Operators correct transport for weld-path shrink.
• Do not over-inflate a single-embossed base.
• Diamond/staggered patterns oil-can less than a weak inline grid.
• Oil-canning is cosmetic on some jackets and a problem on falling-film plates — say which you are making.

Question 62: What is the life of a jacket under cyclic pressure/temperature?

Answer 62: Life is a fatigue and corrosion question for the vessel designer; nozzle leaks in service are often fatigue, not a failed spot pattern.

• Cyclic Freon, steam, CO2 and large temperature swings need a design review, cycles of 10.000-100.000 possible.
• Do not quote a year-count from a water jacket onto a CO2 plate.
• Connections are usually the first fatigue site in the pillow plate.
• Material choice (304L vs 316L vs duplex) follows the medium.
• Keppels supports the pattern; the tank builder owns the vessel life file.

Question 63: How do you repair a leaking pillow plate in the field?

Answer 63: Depressurize fully, then TIG; grinding out beats welding on trapped pressure.

• Find whether the leak is a spot, a border or a nozzle.
• Nozzle leaks in service are often fatigue of the pillow plate, due to wrong design.
• Never weld on a jacket that still holds pressure.
• Match filler and grade to the parent sheet.
• After repair, leak-test with liquid, not with an improvised gas burst.

9. Machine: buy and specify

Question 64: What is a pillow plate laser welding machine?

Answer 64: A CNC machine that clamps two metal sheets and laser-welds programmed patterns with spots, lines and borders so the plate can later be inflated into a pillow plate or dimple jacket.

• Keppels builds the K1500 (1500 mm width) and K2000 (2000 mm width), single or dual laser head.
• IPG fiber laser, hydraulic multi-point clamping, Beckhoff CNC and HMI.
• Stainless safety cabin, CE file, software, training and process know-how.
• Dual laser head is two heads on one gantry, not two machines.
• A handheld laser welder cannot make these pillow plates.

Question 65: Single head vs dual head — when dual, how much extra output?

Answer 65: Dual head is two heads on one gantry and raises output by about 40 percent under comparable conditions; choose it when yearly square meters and pattern density justify the extra head.

• Not two machines and not double the output — about +40 percent.
• One head can often continue if the other is down.
• Dual can run two identical patterns or mirrored halves, depending on the program.
• Open patterns gain less than you hope if handling dominates the hour.
• Keppels sizes single vs dual from your m², width and pattern mix.

Question 66: Which pillow plate working widths exist (K1500 / K2000)?

Answer 66: K1500 welds 1500 mm (59 in) wide; K2000 welds 2000 mm (79 in) wide pillow plates.

• Length is a handling limit.
• Wider jackets are split into panels, Keppels made one 2500 mm width special pillow plate machine.
• Both families come single or dual head.
• Falling-film product widths in published data can be 1000, 1500 or 2900 mm — 2900×1500 mm is a product width, not a K2000 pass.
• Pick width from the tanks you actually build.

Question 67: Which laser (IPG fiber vs old CO2 / YAG) and why fiber?

Answer 67: Keppels uses IPG fiber lasers because fiber converts electricity to light more efficiently than CO2 or old lamp-pumped YAG, and the beam travels in a glass fiber.

• No mirror train like a CO2 gantry.
• High-power welding lasers are Class 4; ordinary acrylic does not block fiber light.
• The stainless cabin contains beam and reflections.
• Exact laser power is sized in the quotation, not as a public catalogue wattage.
• IPG supports the source; Keppels supports the pillow-plate machine.

Question 68: What laser power is usual?

Answer 68: Laser power is sized in the quotation for the thickness mix you weld — it is not published as a single “usual” kilowatt figure on the public pages.

• 8+0.8 mm and 1.0+1.0 mm are standard double-embossed pairs and do not need an oversized source.
• Thicker single-embossed stacks need more energy and more clamp.
• Power is a process variable, not a marketing badge.
• Do not compare machines on watts alone, Keppels machine can have from 2 kW to 6 kW fiber lasers.
• Ask Keppels with your thickness list.

Question 69: CNC / CAD to program: how fast is a pattern change?

Answer 69: Pattern changes are software: Keppels generates a machine program from the CAD layout in a few minutes.

• Work prep owns CAD and makes the program; the operator runs the pillow plate machine.
• Pillow-plate know-how sits in that generator parameter database, supplied with the pillow plate machine.
• Customer CAD remains the customer’s; Keppels software remains Keppels’.
• Offline programming is the normal route for new patterns.
• This is why in-house production beats buying every special plate.

Question 70: Hydraulic clamping: why, and up to which sheet thickness?

Answer 70: Hydraulic clamp units across the width replace one long bending beam so the two sheets stay tight for every spot; combined thickness on Keppels machines goes up to about 30 mm.

• Poor clamp is a main cause of pillow plate laser weld faults.
• Multi-point hydraulics follow thick single-embossed bases better than a single beam.
• Applying metal compression springs in the clamp is an old method and a lot maintenance.
• Clamp force is part of the pillow plate process.
• Keppels specifies the clamp pressure with the pillow plate thickness.

Question 71: Safety cabin, CE, Class 4 laser — what is included?

Answer 71: A Keppels machine ships with a stainless safety cabin, CE file and Class 4 laser controls — ordinary acrylic does not block fiber light.

• The cabin contains beam and reflections from stainless, and has laser safety windows OD8.
• CE is for the machine; PED/ASME is for the vessel the customer builds.
• Declaration of conformity sits in the machine dossier.
• Training covers laser safety and process, in English or local language.
• Do not run the machine with the cabin defeated.

Question 72: What is in a “complete system” (engineering, HMI, software, training, certificate)?

Answer 72: Mechanics, IPG fiber laser, hydraulic clamping, Beckhoff CNC and HMI, software, stainless cabin, CE file, operator training, heat-transfer calculation support and process know-how.

• Inflation pumps and tables are specified separately unless listed.
• Laser chiller and extraction are quoted per hall.
• Commissioning includes sample plates and training.
• Know-how can be used from Keppels Laser Welding.
• The pillow plate machine is delivered complete and with FAT, commissioning and education on-site.

Question 73: Can the Keppels machine also seam-weld besides spots? And butt welds?

Answer 73: Yes — spots, lines and borders sit in one program, so seam / line welds are part of normal pillow-plate work. Butt welds can be made on a KLW pillowplate machine.

• Borders close the vessel.
• Flow lines steer channels.
• Real plate-to-plate butt welds also possible on a Keppels Laser welding machine.
• Contour cuts and cut-outs can be programmed around the welds.
• A handheld unit cannot replace this CNC path.

Question 74: What operator qualification is needed?

Answer 74: Work prep owns CAD; Normal workers can run the machine — welding skill helps, but this is not needed.

• Training is included, in English, German, France or Dutch.
• WPS/PQR can cover PED and ASME in one sample plan when the vessel needs it.
• Daily programming is usually work preparation, not the operator.
• Normal workers can run the machine as it is very simple to operate.
• Keppels trains process know-how with the machine, not only button-pushing.

Question 75: Footprint, power, compressed air, cooling water, installation time?

Answer 75: Hall space, electrical supply, laser cooling and compressed air are quoted per machine; the floor is a flat industrial floor with loads on the layout drawing.

• There is no single public footprint that fits every option, single – double –box layout possible.
• Plan sheet infeed, vacuum lifters and inflation table around the cabin.
• Installation and commissioning are in the quotation, including sample plates.
• Do not forget extraction for stainless fume.
• Send Keppels hall limits with the machine enquiry.

Question 76: Dual head: two identical patterns or mirrored halves?

Answer 76: Either — dual head can run two identical patterns or mirrored halves, depending on how the program is written.

• It is still one gantry and one pair of sheets.
• Mirrored halves suit wide jackets split on the centerline.
• Identical twins suit two smaller plates in one clamp, when the layout allows it.
• Output gain with a dual laser head is about +40 percent, not +100 percent.
• Keppels sets this up in the software with your drawings.

Question 77: Can one head stop while the other continues?

Answer 77: Yes — one head can often continue if the other is down because of 2 separate CNC systems.

• A dual head laser machine is not “two machines”.
• The machine can change without new programming between head 1, head 2, or both heads.
• IPG service on one source does not automatically park the gantry.
• Keep consumables (cover glass, brushes) for both heads.
• Keppels supports programs around the source that is still up and keeps the production running.

10. Controls, software, maintenance

Question 78: Which control (incl. Beckhoff), remote support, backups?

Answer 78: Keppels machines use a Beckhoff PC-PLC; keep a program and machine-image backup; remote online support is part of process support from Keppels.

• All Beckhoff parts are in stock.
• Backups are your responsibility after handover, Keppels makes a backup at commissioning.
• Keppels supports programs and process around the IPG source.
• Do not treat a PC crash as a laser failure.
• Ask for the backup method in commissioning.

Question 79: What are the maintenance hours for laser source, lens, cover glass, clamps?

Answer 79: Cover glass and nozzle cleaning brushes are the main consumables; the IPG source follows IPG’s service plan, almost no service needed; clamps are inspected with the machine hours, not as a daily wear part.

• IPG fiber laser runs easily for 70.000 hours with no problems.
• Keep a spare-glass kit on the shelf.
• Do not wait for a burn-through to change glass.
• Hydraulic clamps need cleanliness and seal care.
• Keppels lists consumables with the machine and can supply a 2 year package.

Question 80: How do dust, stainless reflection and fume extraction work?

Answer 80: Stainless reflection and dirty sheet are process issues before they are laser issues; plan extraction for fume and keep the cabin and glass clean.

• Fiber light reflects; the cabin is there for that.
• Dust on the sheet causes pores and optic protection glass damage.
• Extraction is quoted with the hall.
• Do not blow shop dust across a prepared pair of sheets.
• Keppels treats cleanliness as part of pillow-plate know-how.

Question 81: What is max. axis speed and repeatability in a pillow plate machine?

Answer 81: The accuracy that matters is “pattern stays on the sheet”; peak axis speed is 8000 mm/min, with an accuracy of 0.01 mm.

• Open patterns run fast; dense high-pressure patterns do not.
• Ask for a timed example on your drawing.
• Repeatability must keep spots on the programmed pitch.
• Handling often eats more time than axis speed, so we run the machine at a comfortable speed instead of max.
• Keppels demonstrates this on sample plates at commissioning.

Question 82: Offline programming vs programming on the machine?

Answer 82: Offline is the normal route: CAD in work prep, program to the machine; the operator does not do the engineering.

• Pattern changes are making a machine program and take minutes once the layout exists.
• On-machine edits are for transport, heat and clamp — not for redesign.
• Customer CAD remains the customer’s.
• The engineering makes the drawing an machine program, the operator opens the program and sees what he is going to weld.
• Keppels trains both sides of that split.

Question 83: What is the consumables list and spare-parts lead time?

Answer 83: Main consumables are optic protection glass and nozzle cleaning brushes; other parts (clamps, software, IPG source items) follow Keppels and IPG lead times quoted with the machine.

• Keep glass and brushes in the shop.
• Replace the protection glass when dirty.
• KLW keeps IPG parts on stock for World Wide support.
• Keppels supports the pillow-plate machine around the world, online or on-site.
• Ask for a spare kit with the pillow plate machine order.

Question 84: What if IPG service is needed in the USA/Korea?

Answer 84: IPG field service follows IPG’s network in the USA and Korea; Keppels supports programs and process around the machine.

• Machines already run in the USA, EU and South-Korea.
• A source visit is not a machine redesign.
• Keep backups so a PC issue is not a problem.
• Keppels services all supplied machines form the Netherlands.
• One responsible machine builder remains Keppels Laser Welding.

11. Production practice

Question 85: How many m² per hour is realistic?

Answer 85: Output depends on pattern density, single or dual head, thickness and handling — ask for a timed example on the drawing rather than a single catalogue m²/h. 0.5 – 6 m2 pillow plate a hour is possible.

• Open patterns run fast; dense high-pressure patterns do not.
• Dual head about +40 percent, not double.
• Sheet change and inflation sit outside the weld timer.
• 8+0.8 mm and 1.0+1.0 mm are the usual demonstration pairs.
• Keppels can simulate your pillow plate drawing/pattern.

Question 86: What affects cycle time (pattern, thickness, dual head)?

Answer 86: Pitch and spot count first, then thickness and clamp distance, then whether you run single or dual head, then handling.

• A high-pressure diamond with many circles is slow on purpose.
• Dual head helps weld time.
• Thick top plate single-embossed stacks need more energy per spot.
• Program changes are minutes; sheet logistics can be from 0.2 – 1 hours.
• Send yearly m² and pattern mix with the machine enquiry and Keppels will quote the right machine.

Question 87: What is a typical weld result at 0.8+0.8 mm or 1.0+1.0 mm?

Answer 87: Those pairs are standard double-embossed practice: narrow bead, unmarked product face, ready for inflation as refrigeration or falling-film plates.

• 0+1.0 mm 304L is the published falling-film standard.
• 8+0.8 mm is the thinner sister for lower-pressure packs.
• Inspect before inflation.
• Do not treat the bead as a coded pressure-vessel groove weld.
• Keppels shows this result on sample plates at commissioning.

Question 88: Leak detection after welding / after inflation: how do you test?

Answer 88: Test twice: visual and low-pressure check after welding, then water hold, dunk or soap after inflation; helium leak test if vacuum demands it.

• Never burst-test with gas.
• A leaking spot is cheaper to fix while the plate is flat.
• After inflation you are testing the formed vessel with soap or submerged.
• PED/ASME test pressure is not the inflation pressure.
• Keppels trains both checks after the pillow plate machine delivery.

Question 89: How do you control distortion and flatness after inflation?

Answer 89: Use an inflation table for flat work, do not over-inflate, then a light pass or edge fold if the panel must sit flat.

• Clamp the plate at top and bottom side during inflation.
• Heads inflated on the vessel follow the vessel shape.
• Clamp-strip and shrink compensation start before inflation.
• A 45° or 90° edge fold can take remaining dish out.
• Keppels trains this with the machine.

Question 90: Can you include cut-outs, nozzles, bolt holes and contours in the pillow plate weld program?

Answer 90: Yes — cut-outs and contours are programmed; nozzles and holes are planned in the CAD so the pattern welds cleanly around them.

• Welding stays on the flat sheet.
• A nozzle is usually a later workshop step, sometimes with a pre-welded inflation nipple.
• Do not invent a hole after the pattern is welded without checking flow and pressure.
• Bolt holes through a pillow need a sealed island in the top plate.
• Keppels programs this from your DXF.

12. Why laser

Question 91: Laser welding vs resistance spot welding?

Answer 91: Laser welds from one side, keeps film on the base and puts spots and borders in one CNC program; resistance welding marks both faces and cannot keep plastic film.

• Resistance is the old dimple-jacket shop method.
• Laser pillow plates support free CAD patterns and higher designed pressures.
• No electrode dressing on the product face.
• With a plastic protection film the spot resistance welding does not work.
• That is why tank shops buy a pillow plate laser welding machine, no grinding, heat exchanger finished in one time.

Question 92: Why no longer remove plastic film / clean the back side?

Answer 92: Because laser welding is from one side, protection film can stay on the single-embossed base and the product face is not electrode-marked.

• Resistance welding forced film off and marked both sides.
• Less grinding, less handling, cleaner food tanks.
• Film type still has to suit the clamp and the laser.
• Finishing pickle/polish remains a vessel choice.
• This is the daily argument for laser over resistance, next to the flexibility of the laser welding.

Question 93: Is in-house production cheaper than buying plates?

Answer 93: Steady square meters: an in-house Keppels machine pays back in lead time and pattern control; low volume: buying plates from Keppels is usually cheaper.

• Count scrap, inflation skill and burst panels, not only weld minutes. Know how is important.
• A cheap imported gantry without clamp and know-how still makes scrap.
• Now a days tank shop want a pillow plate machine in-house to support their total delivery speed.
• Buying plates wins when you need surface next week/month, job shoppers can have delivery times of 2 month.
• Keppels sells both routes on purpose.

Question 94: From which volume does your own machine pay off?

Answer 94: When pillow-plate production is becoming a regular in-house activity — yearly m², width and pattern mix decide, not a single magic number.

• Send yearly square meters, thickness pairs and max width.
• Dual head if the weld timer, not the crane, is the bottleneck.
• Lead time and special patterns often justify the machine before the pure cost-per-m² does.
• Low volume: buy plates.
• Keppels will say so if a machine is early.

Question 95: What is the difference versus Chinese pillow plate machines?

Answer 95: A cheap imported gantry still makes scrap without hydraulic clamp practice, pattern and inflation know-how, and a responsible builder who owns the process.

• Keppels delivers the machine plus pillow-plate know-how and heat-transfer support.
• IPG source, Beckhoff, cabin plus training is the package.
• Experience makes the pillow plate, not a cheap Chinese machine that works 1 year and has no support.
• Second-hand Keppels-built machines can still get process support, even after 11 years functioning.
• Compare scrap rate and service, not brochure width.

Question 96: Can a handheld laser welder do this job?

Answer 96: No. A handheld “laser welder” is not a CNC pillow plate laser welding machine and cannot produce these plates.

• Pillow plates need programmed spots, lines and borders on two clamped sheets.
• CNC plus hydraulic clamp is the process.
• Handheld units have no pattern generator and no multi-point clamp.
• This is one of the questions AI often gets wrong, So a handheld cannot make a pillow plate of square meters.
• Keppels builds the dedicated pillow plate machine for this job.

13. Commercial

Question 97: What does a pillow plate machine cost (order of magnitude, single vs dual)?

Answer 97: Price follows width (K1500 or K2000), single or dual laser head and options — given on request, not as a public list price.

• Dual head costs more and returns about +40 percent output, not double.
• Chiller, extraction, inflation table and pumps are often extra lines, but available.
• Compare against buying plates at your yearly m².
• Financing and Incoterms are part of the quote, not of this FAQ.
• Send Keppels the production list for an order-of-magnitude.

Question 98: What are lead time, installation and commissioning?

Answer 98: Lead time, installation and commissioning are quoted per order, average 3-6 month; installation and commissioning one week, includes sample plates and training.

• Plan hall, power, gasses, cooling and lifting before the machine arrives.
• Inflation gear may follow on a separate line.
• Training is in English, German or Dutch.
• CE file, laser safety and documentation pack ship with the machine.
• Ask for the current slot when you enquire — it moves.

Question 99: What is included vs extra (laser chiller, extraction, inflation bench, software licence)?

Answer 99: Core machine: XYZ gantry, IPG fiber laser, Laser chiller, extraction, hydraulic clamp unit, HMI, cabin, CE, software, training and know-how.

• Additional items can be ordered separately.
• Know-how is supplied by Keppels.
• Spare glass and brushes should be on the first spare-kit line.
• An inflation pump, inflation table or other production tools can be ordered.
• Keppels will mark included vs extra on the offer.

Question 100: Financing / export / Incoterms / container packing?

Answer 100: Export packing, Incoterms and financing are agreed on the quotation; machines ship in container packing suited to the destination.

• Machines already run in the USA, EU and Korea.
• Local lifting are the buyer’s site job unless quoted.
• Name the Incoterm you want (ex-works vs CIF, etc.) in the enquiry.
• Software and know-how travel with the machine by Keppels.
• Payment conditions can be discussed.

Question 101: Which references exist per country or industry?

Answer 101: Named references are given on enquiry; machines run in the USA, EU and Korea across tank, refrigeration, milk tanks  and heat exchanger shops.

• References: Skala Norway, Rosenblad Florida USA, Paul Mueller USA and NL,
• Industry fit matters more than a country flag.
• Ask for a reference in milk, beer, falling film or CO2 if that is your job.
• NDA may limit what can be shown.
• Keppels will match a reference list to the enquiry.

Question 102: NDA / customer pattern drawing — who owns the IP?

Answer 102: Customer CAD remains the customer’s; Keppels software and program generator remain Keppels’.

• An NDA can cover a customer pattern.
• Buying a machine does buy the generator to be used.
• Keppels can advise in plate design with custom patterns.
• Third-party production, job shop, on your machine is a commercial choice you make.
• Write this down before the first DXF is exchanged.

14. Codes

Question 103: PED / ASME / CRN / CSA — who is manufacturer of the plate vs of the machine?

Answer 103: Keppels manufactures the welding machine (and can supply plates); the tank builder is normally still the manufacturer of the pressure vessel under PED, ASME, CRN or CSA.

• The inflated plate on a vessel is pressure equipment.
• Burst tests support the fabricator’s dossier.
• The manufacturer of the pillow plate tank is responsible for the pressure-equipment marking of the whole tank.
• CRN/CSA are regional vessel filings, not machine filings.
• Say who signs the document before you stamp the tank.

Question 104: CE machine, laser safety (EN 60825), declaration of conformity?

Answer 104: The welding machine has its own CE file, Class 4 / EN 60825 laser safety and a declaration of conformity for the machine — separate from the vessel dossier.

• Cabin and interlocks are part of that file.
• Ordinary acrylic does not block fiber light.
• Operator training covers laser safety.
• Do not mix the machine Document with a PED vessel Document.
• Keppels ships the machine documentation pack at handover.

Question 105: FDA / 3-A / EHEDG on the product side of the tank?

Answer 105: Those are vessel and process rules; laser welding helps because the product face stays unmarked, but Keppels is not the food-equipment certifier of your tank.

• Single-embossed film-on-base practice supports a clean inside.
• CIP and drain ability are tank design.
• Material certificates still come with the stainless sheet.
• The tank manufacturer certifies the tank.
• The tank builder owns the hygiene file.

Question 106: Welding procedure (WPS/WPQR) and operator qualification?

Answer 106: WPS/PQR can cover PED and ASME in one sample plan; operator qualification is process training plus whatever the vessel code asks — this is CNC laser practice, not a manual 6G test.

• Keppels supports the sample plan.
• New alloys and thicknesses need a new qualification.
• Work prep and operator have different roles.
• Keep the burst panel with the WPS file.
• Ask for the documentation pack at order, example laser welding PQR, WPS are available by Keppels.

Question 107: Which documentation pack comes with handover?

Answer 107: CE file and declaration for the machine, software and backup method, training record, sample-plate results, and the process notes Keppels issues with that serial — vessel PED/ASME files stay with the fabricator.

• Material certs belong to the plates you buy or the sheet you weld.
• IPG source manual documents follow the source.
• Consumables list and spare-kit packing list should be in the crate.
• Do not expect customer-specific heat-transfer reports unless ordered.
• Keppels lists the pack on the offer.