Still & Mineral Water — Frequently Asked Questions

🎯 Key takeaways

1. 2,000–48,000 BPH across 0.2–16 L, with small and large formats on separate machine families
2. Gravity and mechanical for plain water, volumetric for exact volume, load cell only above 5 L
3. Natural mineral water excludes RO, softening and remineralisation — filtration plus permitted disinfection only
4. Ozone needs ozone-rated seals and 316L on the contact path; UV leaves no residual and protects nothing downstream
5. Commissioning delays are usually site readiness — power, air or treated water not ready when engineers arrive
6. Ask three questions in writing: sustained output on your largest bottle, quotation exclusions, and changeover time between your two main formats

On this page

1. Selection questions
2. Technical questions
3. Water treatment questions
4. Installation & commissioning
5. Certification & compliance
6. Commercial questions
7. Related resources
8. FAQ

1. Selection questions

The questions buyers ask before a specification exists. Fuller treatment of the selection logic is in the water machine selection guide.

What output should I buy for a new water plant?

Size on the volume you can sell within roughly two years, not on the market you hope to hold in ten. A regional start-up is usually served by 4,000–12,000 BPH. Idle capacity is not free — it carries the same installed power, the same footprint and a larger spare part inventory, and wear parts consumed slowly are bought at worse unit prices. Plan the building layout for a second line instead of over-sizing the first.

Can one machine run 0.5 L and 5 L bottles?

No. Small format 0.2–2 L and large format 3–16 L are separate machine families. Mould size, clamping force, gripper design, filling time and cap diameter all differ, and a 15 L bottle cannot be carried by its neck ring when full. Plants selling both formats buy two lines, usually at very different speeds.

Do I need a combiblock or separate machines?

Above roughly 12,000 BPH on standard 0.2–2 L formats a blow-fill-cap block normally wins on bottle weight, floor area and operator count. Below about 8,000 BPH, on large formats, on unusual bottle shapes, or where you also sell empty bottles, separate blowing plus a rinser-filler-capper remains the better purchase.

How many filling valves will my line have?

As an indicative check, a still water valve delivers roughly 600–900 bottles per hour at 0.5 L and fewer at 1.5 L, so 24,000 BPH typically needs 28–40 valves. Blowing cavities follow a similar rule at 1,500–2,000 bottles per hour per cavity at 0.5 L. Use these to sanity-check a quotation, not to specify from.

What information does a supplier need to quote?

• Target output, stated at a named bottle size and fill volume
• Every bottle format you intend to run, including the ones planned for later
• Bottle and preform drawings, or samples, plus the cap specification
• A laboratory analysis of the source water
• Site conditions: power supply, ambient temperature, building dimensions and door openings
• Which scope items you want included: treatment, CIP, compressed air, labelling, packing, palletising

2. Technical questions

Which filling principle is most accurate for water?

Load cell weighing, followed by volumetric flow metering at typically ±0.5% of target volume. Gravity, mechanical and semi-electric valves fill to a level, so their delivered quantity tracks bottle volume scatter. For water sold by nominal volume with a normal tolerance, level filling is usually sufficient; the case for measured dosing strengthens as container size grows.

Why does a bigger bottle run slower?

Two independent reasons. The mould cavity needs longer to cool a larger bottle before it can be ejected, and the filling valve needs longer to deliver more liquid. Neither is a machine limitation that a different supplier removes; they are properties of the process. A line rated at a small format will not hold that rate on a large one.

How light can a water bottle be?

Lighter inside a block than on a line with an air conveyor, because a neck-handled bottle never rides on its base and does not need the stiffness margin that conveyor travel demands. The achievable weight is set together with the preform supplier and the mould designer against bottle height, neck finish and the top load your distribution requires. Any figure quoted before the bottle drawing is reviewed is a guess.

What compressed air quality does the blower need?

Dry and oil-free at the machine tie-in point, not merely at the compressor outlet. Moisture carried down a long air main produces bottle wall defects that are then blamed on the blower. Specify dryer capacity and filtration for the full blowing demand at rated output, and check the dew point at the machine rather than in the compressor room.

How is the line cleaned?

Water lines run a CIP circuit through the product path: rinse, detergent circulation, intermediate rinse, sanitisation and final rinse with treated water. Frequency depends on the product and the local requirement. Specify CIP with the line rather than adding it later — retrofitting a cleaning circuit into an installed product path is far more expensive than including it.

What causes fill level variation?

3. Water treatment questions

What treatment does a bottled water plant need?

It is decided from a laboratory analysis of the source water, not from a standard package. A typical purified water train is multimedia filtration, activated carbon, softening where hardness demands it, reverse osmosis, then disinfection by ozone or UV and remineralisation if taste requires it. A mineral water train is much shorter because most of those steps are not permitted.

Why can mineral water not use RO or softening?

Because the product is defined by its mineral composition at source. Reverse osmosis, ion exchange softening and remineralisation all change that composition, so most regulatory systems exclude them for natural mineral water. Permitted treatment is generally limited to physical separation — sand filtration, microfiltration and ultrafiltration, typically 0.01–0.1 µm — plus locally permitted disinfection.

Ozone or UV?

They do different jobs. UV at 254 nm disinfects water passing through the chamber and leaves no residual, so it protects nothing downstream of itself. Ozone leaves a residual that carries into the bottle and treats the headspace after capping, then decays over the following hours. Many plants run both: UV as a continuous barrier and ozone where a residual is wanted at the point of fill.

What does ozone do to the filling machine?

Ozonated water attacks ordinary elastomers. Seals, gaskets and O-rings in the ozone contact path must be specified for ozone service, and stainless steel grade matters more than on a plain water line — 316L is normal for the ozone contact path. Declare ozone use at quotation stage so the material specification is correct from build.

Is bromate a concern?

Only if the source water contains bromide. Ozonation of bromide-bearing water can form bromate, which is regulated in most markets. This is checked against the water analysis before the ozone dose is set, not discovered in the first product test. Where bromide is present, the usual response is to control the ozone dose and contact time, or to use UV as the primary barrier instead.

How much water does the plant itself consume?

More than the volume you bottle. Reverse osmosis rejects a share of feed water as concentrate, the rinser uses treated water on every bottle, and CIP consumes water on every cycle. Where water is scarce or expensive, rinse water recovery and RO concentrate reuse are worth evaluating at design stage rather than after installation.

4. Installation and commissioning questions

What does the building need to be ready for?

• A level floor with the load capacity and any foundation work completed
• Power supply at the correct voltage and frequency, with stable distribution to the machine
• Compressed air generation, drying and filtration sized for the blowing demand
• Treated water available at the required quality and flow, not just connected
• Drainage, ventilation and lighting in the production area
• Access route for the machine sections, including door widths and crane or forklift capacity

How long does commissioning take?

Work in phases rather than a single duration: mechanical installation, utility connection, water running, product running and speed ramp, then training. Still water commissions faster than carbonated product because there is no foaming behaviour to tune. Delays are usually caused by site readiness — power, air or treated water not available when the engineers arrive — rather than by the machine.

Why does site output sometimes lag the factory test?

A machine that passed a witnessed test does not deteriorate in a container. Check compressed air dryness at the machine, voltage stability, the preform batch and the cap supplier before concluding anything about the equipment. Testing at the factory with your own preforms and caps, in production quantity, removes most of this uncertainty before shipment.

What is checked during the factory acceptance test?

Mechanical operation, control system function, safety interlocks, output at rated speed and fill quality on your own materials. Send real preforms and real caps in production quantity: testing on generic materials and then discovering yours behave differently defeats the purpose. Agree the acceptance criteria in writing before the test is scheduled.

How many operators does a water line need?

One at the filling block itself. Additional people are needed downstream for labelling, packing, palletising and material handling, and the count there depends on how much of that is automated. The saving from an integrated block is at the block, not across the whole plant.

5. Certification and compliance questions

What certification does Sunswell hold?

ISO 9001 and CE certification, with SGS audit. Equipment is manufactured in a 20,000 m² facility and 444+ lines have been delivered to 71+ countries. These are company and equipment credentials; market-entry approval for your destination country is a separate process.

Who handles destination-market certification?

It is handled with your importer, because the applicable scheme depends on the destination and on who acts as the responsible party for import. Sunswell supplies the technical documentation, drawings and declarations needed to support the process. Start it early — certification timelines run in parallel with manufacturing, and treating them as a post-shipment task delays commissioning.

What food-contact documentation is available?

Material specifications for product-contact components, including stainless steel grades and elastomer types, are supplied with the machine documentation. State the destination market at quotation stage if a specific food-contact standard applies, because it can affect the elastomer and gasket specification.

Does the equipment come with electrical documentation?

Yes — electrical schematics, component lists, mechanical drawings and operation and maintenance manuals. Confirm the language of the documentation and of the operator interface at order stage; both are configurable and both are easier to specify before manufacture than after.

6. Commercial questions

How much does a water bottling line cost?

Price scales mainly with capacity, number of blowing cavities and level of automation, then with contact-part material and downstream packaging scope. Figures quoted without a defined scope are misleading. Send bottle drawings, format mix and target output and request a written quotation against a stated scope. Tier-by-tier cost drivers are set out in water machine configurations compared.

What is usually missing from a cheap quotation?

Water treatment, CIP, compressed air generation and drying, format parts and moulds for additional sizes, installation and commissioning, training, and a commissioning spare part set. Build one scope list, send it to every supplier and require each to answer it line by line including exclusions. Most apparent price gaps close once the scope is normalised.

What are the main running costs?

Electricity first, and within it the high-pressure air for blowing is the largest single item. Then treated water including RO reject and rinse water, labour, consumables such as caps, labels and film, spare and wear parts, and the cost of unplanned downtime. Resin is normally accounted as a material cost rather than an operating cost.

Can an economy line be upgraded later?

Downstream automation, labelling and palletising can be added. Filling valve count, blowing cavity count and the filling principle are fixed at build. Buying a small carousel intending to add valves later is not a workable plan — if the output roadmap is real, size for it or plan a second line.

What after-sales support is available?

Sunswell operates local service presence in 9+ countries and supports installations across 71+ export markets with remote diagnostics, spare part supply and engineer visits. Agree response expectations and the spare part list in the contract rather than after the first breakdown.

The three questions that prevent most disputes. Ask every supplier, in writing: what is the sustained output on my largest bottle; what is excluded from this quotation; and what is the changeover time between my two most common formats. Answers to those three separate comparable quotations from ones that only look comparable.

7. Related resources

Longer treatments of the subjects touched on above:

• Still and mineral water machine selection guide — the three-axis method with a cross-selection table
• Water machine configurations and price levels compared — economy, mainstream and high-speed tiers with a TCO framework
• Combiblock for still and mineral water — what the blow-fill-cap block changes for water production
• Combiblock capacity selection — capacity bands across every product family
• Filling valve types compared — gravity, mechanical, semi-electric, volumetric and load cell

Delivered water installations include C002 Taza, running four 12,000 BPH combiblock lines on 1.5 L bottles in Kazakhstan, and C005 Rauan, with eight bottling and canning lines between 12,000 and 24,000 BPH.

Frequently asked questions