Plate Heat Exchanger Cleaning Chemicals: A CIP Selection Guide

Clean-in-place (CIP) restores heat transfer and pressure drop without opening the plate pack, but only when the chemistry matches the deposit and the plate material. The wrong agent at the wrong concentration either fails to remove the fouling or attacks the plates and gaskets — turning a routine clean into a costly failure. Always start by identifying the deposit type (mineral scale, organic/biological, oil/grease or process-specific) before selecting a chemical.

The sections below help you identify which family of cleaner suits your deposit and whether it is compatible with your plate alloy and gasket compound. They deliberately do not state a concentration, temperature, contact time or rinse specification, because those values are unit-specific and product-specific. Take them from two sources only: the heat exchanger manufacturer's operating and maintenance manual for your model, and the cleaning chemical supplier's approved procedure and safety data sheet. Where the two disagree, follow the more restrictive limit and contact both suppliers before proceeding.

Use this at-a-glance guide to match the deposit to the family of chemistry. Mineral scale (calcium carbonate, oxides, rust): acidic cleaner, commonly citric, nitric, phosphoric or sulphamic based. Organic, biofilm, protein and fat fouling: alkaline cleaner, commonly caustic based. Mixed fouling (food, dairy, brewery): a two-stage sequence, normally alkaline first and then acid, with water rinses between. Stainless steel (304/316L): avoid hydrochloric acid and all chloride-bearing agents. Titanium: tolerates chlorides and most acids, but never use hydrofluoric (HF) acid. Operating conditions and the rinse sequence come from the manufacturer's manual and the chemical supplier's approved procedure.

Acidic agents dissolve inorganic deposits — calcium carbonate scale, metal oxides, rust and other mineral fouling typical of cooling water and hard-water duties. Common families are nitric acid, citric acid and phosphoric or sulphamic acid formulations. Citric acid is the gentlest, widely used food-grade option; nitric acid is more aggressive and is used on heavier scale. The usable strength, temperature and circulation time depend on the plate alloy, the gasket compound and the specific formulation, so take them from the manufacturer's manual and the chemical supplier rather than from a generic table. Never use hydrochloric acid on stainless steel plates — chlorides cause pitting and stress corrosion cracking.

Alkaline agents remove organic matter, biofilm, proteins, fats and oils — the dominant fouling in food, dairy, brewery and many process duties. Caustic-based cleaners are the standard, often combined with surfactants and sequestrants in formulated products. In hygienic plants a two-stage CIP is common: an alkaline cycle to remove organics, followed by an acid cycle to remove mineral scale, with a water rinse between and after each stage. The dosing, temperature and cycle time for each stage must come from the manufacturer's manual and the chemical supplier's approved procedure, and must stay inside the confirmed temperature limit of the gasket elastomer.

Stainless steel (304, 316L) tolerates most nitric, citric and caustic CIP chemistries, but is vulnerable to chlorides — never clean stainless plates with hydrochloric acid or chloride-bearing agents, and limit free chlorine in any biocide. Titanium plates are far more forgiving of chlorides and most acids, but are attacked by hydrofluoric acid and by hot, concentrated reducing acids — avoid HF-based descalers entirely. For both materials, keep acid concentration and temperature within the exchanger manufacturer's and the chemical supplier's limits, and confirm gasket compatibility (EPDM, NBR, FKM) before circulating.

Cleaning effectiveness depends on the balance of concentration, temperature, flow turbulence and contact time, and every one of those four is bounded by the plate alloy, the gasket compound and the formulation in use. There is no universal set of values, and this page does not publish one. Obtain the permitted ranges from the exchanger manufacturer's operating and maintenance manual and the chemical supplier's approved procedure, then work at the lowest concentration and temperature within those ranges that clears the deposit, and maintain turbulent flow (forward and reverse where the manual allows) to lift loosened material. Verify success by checking that pressure drop and heat transfer have returned toward the clean baseline.

CIP chemicals are corrosive — use appropriate PPE, dose into water (never water into acid), and follow the supplier's safety data sheet. The rinse specification, including whether and how the circuit is neutralised before return to service, is part of the exchanger manufacturer's procedure and the chemical supplier's instructions; it is not the same on every unit or with every product, so follow the documented procedure rather than a general rule. Separately from the machine, spent cleaning solutions themselves normally have to be neutralised before disposal — dedicated neutralising products exist for exactly this step — and disposal must follow local environmental regulations.

If you are unsure which chemistry suits your deposit and plate material, send your fouling type, plate material, gasket compound and operating conditions to Blair at blair@shheatex.com or WhatsApp +86 133 1175 6331. Our engineering team will recommend a safe CIP procedure and supply compatible replacement plates and gaskets when needed.