Hygiene in food and beverage liquid transfer is not settled by a single material choice. It rests on three separate layers that have to be addressed together. The first is hygienic design: every product-contact surface must be cleanable, drainable and free of dead volume. The second is food-contact material compliance, which covers gaskets, hoses and plastic parts as much as metal surfaces. The third is operational hygiene: cleaning cycles, tankers reserved for food, and a record of every transfer.
This page outlines where food-grade liquid transfer departs from petroleum and chemical terminal practice and points to the solution pages in this section, each of which answers one specific question.
Why terminal habits from oil and chemicals do not carry over
Topic | Fuel and chemical transfer | Food liquid transfer |
Main risk driving design | Ignition, vapor emissions, overfill | Microbiological, chemical or physical contamination of the product |
Cleaning | Done at product changeover or during maintenance | Part of routine operation; the system is designed around the cleaning cycle |
Transport vehicle | Compatibility with the previous load is checked | A tanker reserved and marked for food, with effective cleaning between loads |
Material selection | Corrosion and chemical compatibility | Corrosion compatibility plus food-contact material compliance |
Measurement challenges | Temperature, density and vapor loss | Entrained air, foam and hygienic installation constraints |
Records | Quantity and custody transfer data | Quantity plus batch, temperature and cleaning records |
EU food hygiene law spells out part of this difference. Bulk liquid foodstuffs are to be carried in receptacles or tankers reserved for food transport and marked as such in a clearly visible, indelible way, and effective cleaning has to take place between loads to avoid contamination. The same regulation requires food-contact equipment to be effectively cleanable, made of suitable materials and installed so that it and the surrounding area can be cleaned properly.
Why stainless steel alone does not make a design hygienic
Choosing stainless steel is a corrosion and material-compatibility decision. Even stainless steel is not corrosion resistant under every condition: in small, oxygen-starved areas such as mechanical joints, tight corners and poorly finished welds, crevice and pitting attack can occur. Hygienic design is a separate set of requirements: cleanability, self-draining geometry, no dead legs or crevices, suitable surface finish, hygienic connections and a validated cleaning cycle.
The distinction shows up in instrument selection too. A stainless meter with flanged ends is not hygienic by default; one manufacturer's data sheet states that its hygienic design approvals apply only with specific hygienic process connections and a specific case option. EHEDG likewise notes that it typically certifies individual components rather than large, complex processing systems. A line built from certified parts therefore still needs its own assessment of how it will be cleaned as a whole.
Food-contact materials
In the EU, Regulation (EC) No 1935/2004 is the framework rule for all food-contact materials: they must not transfer constituents to food at levels that endanger health or change the food's composition, taste or odor unacceptably, and traceability and compliance documentation are required. Plastic materials are additionally covered by Regulation (EU) No 10/2011. For projects aimed at the US market, 21 CFR Part 177 becomes relevant for gaskets, hoses and other polymer components. In practice, compliance declarations need to be agreed for every seal and hose in the scope of supply, not just for pipe and body materials.
Cleaning is part of the design, not an add-on
Clean-in-place (CIP) is the automated cleaning of equipment without disassembly using validated procedures; sterilize-in-place (SIP) is added where the process requires it. Getting cleaning solution to every surface and draining the line completely is only possible when pipe geometry and instrument placement are planned for it from the start; cleaning arrangements bolted on later rarely work as intended. Cleaning chemicals and temperatures are also selection criteria for sensors and seals.
Solutions in this section
· Food-grade truck loading systems: Protecting hygiene, limiting product loss and keeping records when loading tankers.
· Food-grade truck unloading systems: Verifying quantity and quality when receiving product from a tanker.
· Sanitary metering skids: Choosing hygienic meters and connections, and where device approvals stop.
· Hygienic transfer systems: Designing hygienic lines with the right pumps, valves, slope and drainage.
· CIP / SIP compatible systems: Making transfer and metering equipment fit cleaning and sterilization cycles.
· Stainless steel metering systems: Selecting stainless grades and finishes, and how that differs from hygienic design.
Working with TLY Enerji
TLY Enerji's verified services cover selecting measurement and control technology for the process conditions, supplying instruments, valves and pumps, system integration, site installation, testing and commissioning. For a food-grade transfer project, which of these services apply, and who provides the hygienic design and material compliance documentation, is agreed at the outset through the technical specification.
Quick answers
Is food-grade the same as hygienic design?
No. Food-grade usually describes a material that is suitable for food contact, meaning it does not release harmful levels of constituents into the product. Hygienic design is about whether the equipment can be cleaned, drained and kept free of dead volume. A part made of a compliant material can still be a hygiene risk if it contains a crevice that cleaning cannot reach.
Can a loading or metering skid built for petroleum products be reused for a food liquid?
Direct reuse is generally not advisable. Connections, gaskets and meter-run layouts used in petroleum service are typically not chosen with cleanability or food-contact material rules in mind. If reuse is being considered, every product-contact part has to be assessed individually for hygienic design and material compliance before any decision is made.
Is an EHEDG or 3-A approval on the meter enough?
The approval shows that the device meets hygienic design criteria with the stated connections and options; it does not cover the whole line. Mounting orientation, adjacent connections, drain points and the line's cleaning cycle still have to be assessed separately. The sanitary metering skids page covers this in more detail.