Choosing Solenoid Valves for CIP, Food and Beverage Applications
Food and beverage production places unusually tough demands on flow control. A valve used on a dairy filling line, a brewery, or a soft-drinks plant must switch reliably during production and then survive repeated Clean-in-Place (CIP) cycles that pump hot caustic and acid through the same pipework. Getting the valve specification right protects both product safety and plant uptime. This guide walks through the key decisions when selecting a solenoid or process valve for hygienic duties.
Why hygienic applications are different
In most industrial settings a valve simply needs to handle the process media. In food and beverage the valve also has to be cleanable, must not harbour bacteria, and must not contaminate the product with anything that leaches from wetted materials. That means smooth internal surfaces, wetted parts made from approved materials, and construction that drains fully rather than trapping pockets of liquid. It also means the valve has to tolerate the CIP regime, which is often more aggressive than the product itself.
A typical CIP sequence includes a pre-rinse, a hot caustic wash (sodium hydroxide, often at 70–85°C), an intermediate rinse, an acid wash (nitric or phosphoric acid) to remove mineral scale, and a final rinse. The valve sees strong alkalis, strong acids and hot water in a single day, so material compatibility must be assessed against the cleaning chemicals, not only the product.
Body and wetted materials
For direct product contact, 316L stainless steel is the default body material. It resists the acids and caustics used in CIP, tolerates high temperatures, and takes a smooth, easily cleaned finish. Brass is generally unsuitable for hygienic product lines because it can corrode under acidic cleaning and is not favoured for food contact, though it may still appear on ancillary services such as compressed air or non-contact cooling water. Plastic bodies such as PVC or PP have their place on cold, low-pressure water and some dosing duties, but they will not survive hot CIP cycles.
Wherever the valve touches product, look for materials declared compliant with the relevant food-contact regulations, such as EC 1935/2004 in the UK and Europe, or FDA-listed elastomers. If the valve is also used on potable water make-up, a chemical compatibility check should be paired with WRAS approval for that part of the system.
Seal material selection
The elastomer seat and seals are usually the limiting factor, because they meet the media directly and are the most vulnerable to swelling or hardening. The right choice depends on both the product and the cleaning chemistry.
| Seal material | Strengths for hygienic use | Watch points |
|---|---|---|
| EPDM | Excellent with hot water, steam, caustic and dilute acids; a common default for CIP-heavy dairy and beverage lines | Poor with fats, oils and mineral oils; check for fatty products |
| FKM (Viton) | Good with oils, fats and some acids; wide temperature range | Not ideal with hot caustic or steam; can be attacked during alkaline CIP |
| PTFE | Very broad chemical resistance and low product carryover; suits aggressive CIP and flavour-sensitive lines | Harder seat, often used on angle-seat piston valves rather than diaphragm solenoids |
| NBR | Economical and good with oils | Generally avoided for CIP and food contact; limited caustic and temperature resistance |
For a line that is cleaned frequently with hot caustic, EPDM is often the pragmatic choice; for oily or fatty products, PTFE seating avoids the compromise between fat resistance and caustic resistance. Our overview of solenoid valve seal materials covers the trade-offs in more detail.
Valve type: solenoid or air-actuated piston
Compact 2/2 solenoid valves in 316 stainless steel are ideal for dosing, filling, rinse water and utility control where flows are moderate and the media is clean. For hotter, higher-flow or steam-bearing duties — barrier steam, sterilisation, or main CIP supply lines — a pneumatically actuated angle seat piston valve is frequently the better answer. Its Y-pattern body gives high flow with low pressure drop, the PTFE seat handles steam and aggressive cleaning, and it copes with the elevated temperatures that CIP and SIP (Steam-in-Place) cycles impose.
Consider also whether the valve should be normally closed or normally open, and what should happen on power or air failure. A fill valve that fails closed protects against overfilling and spillage, whereas some safety-critical services are specified to fail to a safe state defined by the process risk assessment.
Temperature, pressure and flow
Specify the valve against the hottest condition it will see, which is usually the CIP or SIP step rather than the product. Confirm the body, seat and coil are all rated for that temperature; a valve rated for ambient product but installed on a line that is steam-sterilised will fail prematurely. Size the port for the required flow rather than simply matching the pipe thread — an undersized valve throttles flow and wastes energy, while an oversized one can be slow to seal and more prone to water hammer. Our guides on how to choose a solenoid valve explain how to work from flow rate and pressure drop to a suitable orifice and Kv.
Practical selection checklist
Before ordering, confirm the following for each valve position: the product being controlled and its temperature; the CIP and SIP chemistry and peak temperature; the required flow rate and available pressure; the electrical supply and whether AC or DC coils suit the control system; the connection type and thread standard; and any certification the site demands, such as food-contact compliance or WRAS on potable make-up water. Documenting these at the design stage prevents the common problem of a valve that works fine in production but degrades within weeks of cleaning cycles.
Getting the specification right
Hygienic valve selection is a balance between the product, the cleaning regime and the practicalities of flow and control. When the CIP chemistry is aggressive or the temperatures are high, it is worth confirming compatibility before committing to a large order. If you would like a shortlist tailored to your media, temperature and flow, our Valve Search Wizard narrows the options quickly, and the technical team is always happy to sense-check a specification for a food or beverage line before you order.