filling planning question
Gravity vs Pressure Filling for Still Water: Selection Guide
For still water, compare the actual liquid path and bottle-filling sequence. “Gravity,” “pressure” and “volumetric” can describe different aspects of a filler, so the labels alone do not tell you whether two proposals use the same process.
Separate Product Supply from Bottle Pressure
A pump supplying a filler does not by itself mean the bottle is counter-pressure filled. Ask how liquid reaches the valve, whether the bottle is sealed and pressurized during filling, and what stops each fill.
Understand What Each Term Describes
Gravity feed uses the liquid head from a tank above the filling outlet to drive flow into the container. The system still needs a way to control the amount delivered. Depending on the design, that control can use a timed cycle, a fill-level mechanism or measurement of the delivered quantity.
Counter-pressure filling involves a sealed bottle and a controlled pressure sequence. A typical sequence includes pressurization before liquid delivery and pressure relief before release. That sequence matters for carbonated products; it should not be inferred merely because a still-water filler has a pump or a pressurized product supply.
Flow-meter or volumetric filling describes how delivered quantity is determined. It can be used in different pressure arrangements. Free-jet filling describes delivery into the bottle without a filling-valve seal against the mouth. Ask for the selected machine’s functional description because these terms are not interchangeable competing categories.
Compare the Process Questions Separately
Have each supplier complete the same questions for the proposed water product and bottle. A process diagram and valve sequence are more useful than a single label such as “pressure filler.”
| Process question | What the supplier should describe | Why it changes the comparison |
|---|---|---|
| How is product supplied? | Tank/head arrangement, pump or pressure source, control and required inlet conditions | Identifies the supply boundary without assuming bottle pressurization |
| What happens at the bottle mouth? | Open/free-jet or sealed interface; bottle support and centering | Defines contact and handling arrangements for the approved neck |
| Is the bottle pressurized? | Gas/product sequence and pressure relief, if applicable | Separates counter-pressure operation from a pressurized supply circuit |
| What ends the fill? | Timed control, level detection, flow measurement or another stated method | Explains which quantity is controlled and how it will be verified |
| How is the product path cleaned? | Cleaning method, connections, drainage and verification procedure | Makes the hygiene scope reviewable independently of the filling label |
Define Still Water and Any Future Product Change
Give the supplier the actual treated-water specification and temperature range, bottle and neck drawings, target fill quantity and format rate. For a metered system, ask whether the product properties, including conductivity where relevant to the selected meter, fall within the instrument’s approved application range.
If sparkling water is a future requirement, declare it before selection. A platform offered for still water does not automatically have the pressure control, carbonation interface or approved packaging needed for sparkling products. Some platforms offer both applications, but the specific supplied configuration must state which products it supports.
Likewise, hot filling or an aseptic application needs its own approved process and packaging basis. A stainless enclosure, a rinse station or the word “hygienic” does not by itself establish that capability.
Compare Results with the Actual Bottle
Ask the supplier to demonstrate the agreed fill result across the approved bottle samples and operating conditions. Record actual fill quantity, relevant fill-height checks, bottle condition, spillage or rejects, and the stated counting and timing boundaries. Keep the target, tolerance and test method explicit.
Review the product-contact path, cleaning procedure, drainability and access separately from filling principle. Request the specified cleaning connections, recipe or procedure, and verification responsibilities. Do not assume a different pressure arrangement alone establishes a better hygiene outcome.
Use the test to resolve a specific decision: whether the proposed process meets the approved package, quality and output requirements. A faster isolated fill does not establish higher accepted production when bottle transfer, cap application or downstream packing imposes another limit.
Technical References
Accutek distinguishes gravity feed from pressure-pot supply, illustrating that product delivery arrangements must be identified. Accutek gravity-feed explanation.
Krones describes a non-carbonated-water filler whose flow meter signals the end of the fill, illustrating quantity control within a free-jet system. Krones Modulfill VFJ.
This separate Krones platform describes free-jet operation for still products and counter-pressure operation for carbonated products. It is a technology example, not an aseptic or sparkling-water capability claim for equipment offered here. Krones filling with and without pressure.
<p>Sources checked September 22, 2026. Manufacturer examples do not establish the configuration or performance of a quoted project.</p>
Buyer Questions
Does still water always need counter-pressure filling?
No. Pressureless and free-jet systems are available for still products. Select the supplied configuration using the actual product, bottle, quality requirements and verified performance.
Is gravity filling the opposite of volumetric filling?
No. Gravity describes a source of liquid flow, while volumetric control describes how the delivered quantity is controlled. Ask the supplier to explain both the liquid supply and the method that ends the fill.
Does a product pump make a filler a pressure filler?
A pump can deliver water to the machine without establishing a counter-pressure process inside the bottle. Review the bottle interface and filling sequence.
Can a still-water filler later fill sparkling water?
Only if the supplied equipment configuration and packaging are approved for that application. Confirm the pressure sequence, product preparation, utilities and required changes with the supplier before committing to that plan.
Request a Gravity vs Pressure Filling for Still Water Scope Review
Share what you know now. The goal is to prepare a useful plant brief before a machine quotation is built.