One heater, several skid layouts
A CIP skid is one to four tanks, a supply pump, a return pump, a heater and a valve matrix. Single-tank skids rinse and wash from the same tank. Two-tank skids hold rinse water and wash solution apart. A third tank recovers final-rinse water for the next pre-rinse, and a fourth holds concentrated caustic, acid or sanitizer for dosing. One-pass systems dose chemical into the supply line and heat it once on the way out; multi-pass systems hold solution at strength in the tank and reheat it every circuit.
The parent page sizes the heater on the cycle clock. This page is about the heater itself: where it sits, its steam side, its ratings, and how the tank count sets the duty.
The heater sits in the supply line between the pump and the valve matrix, so every circuit gets solution at temperature whichever tank it came from. Downstream the solution goes to spray balls at 20 to 30 psi, to rotary spray heads at 60 to 100 psi where impact matters, and through pipe circuits and process exchangers at 5 ft/s. The solution side is rated for the pump at shutoff, because a closed valve in the matrix puts the full head on the shell.
The solution side is 304 or 316L, 32 Ra, tri-clamp, drainable to a low point and vented at the top, with a removable U-tube bundle so the shell can be inspected after years of caustic.
Plant steam at 15 to 50 psig enters the tubes through a modulating valve controlled on the outlet RTD and leaves through a trap sized for the start-up condensate load, three to five times the steady load. A vacuum breaker on the inlet lets the tubes drain when the valve closes; without it the bundle floods, the next cycle opens the valve onto standing condensate, and the hammer cracks a tube joint. Steam-side rating is 150 psig at 375 F.
On a single-tank skid the heater does everything: rinse water to 100 to 140 F, then caustic from ambient to 170 F, then acid to 150 F, with no tank held warm between them. It is sized on the caustic rise at full circuit flow and runs flat out for the whole cycle. On a two-tank or three-tank skid the solution tanks are held at 120 to 140 F by a small recirculation heater, and the in-line heater trims the last 30 to 50 degrees; it can be a third the size for the same plant.
One-pass dosing systems have no warm tank, so the heater sees the full rise at full flow every cycle. HeatX asks for the tank count and phase sequence before quoting because the answers move the heater size by a factor of three. Complete sanitary CIP heater packages are covered on our sanitary CIP heat exchanger pages.
Sizing on the boiler nameplate pressure and not the pressure the skid sees when the pasteurizer, the deaerator and the evaporator all draw at once. A heater sized on 50 psig that gets 12 psig at peak has lost a third of its temperature difference and delivers 150 F caustic to a circuit validated at 170 F. HeatX sizes on the lowest steam pressure the skid will see and states it on the drawing. Call and talk it through with an engineer: 1-805-484-2992
A CIP heater is sized to the chemistry and the cleaning steps it serves. Use the rows to compare your own cycle, and send the largest line size and steam pressure along with the quote request.
| Condition | Detail |
| Fluid | 1 to 2 percent sodium hydroxide; 0.5 to 1 percent nitric or phosphoric acid; rinse water; peracetic sanitizer |
| Flow range | 30 to 600 gpm, set by 5 ft/s in the largest line on the circuit |
| Temperatures in / out | Caustic 120 F to 160 to 180 F; acid to 140 to 160 F; pre-rinse 100 to 140 F |
| Hold | 20 to 40 minutes caustic, 10 to 20 minutes acid, held by return temperature |
| Utility | Plant steam at 15 to 50 psig, modulating valve, trap, vacuum breaker |
| Approach | Not limiting on steam; outlet held within 2 to 3 degrees of setpoint |
| Construction | U-tube, steam in the tubes, solution on the shell; straight tube where the plant wants brushable solution tubes |
| Finish / class | 304 or 316L on the solution side, 32 Ra, tri-clamp connections, drainable; 3-A symbol where the inspector asks |
| Ratings | Solution side to the pump shutoff head; steam side 150 psig at 375 F |
| CIP / SIP | The heater is cleaned by the cycle it heats; drained and vented between cycles |
U-tube when steam is in the tubes: the bundle expands freely across a 250 degree swing and pulls for inspection. Straight tube when the plant wants to brush the solution tubes and can put steam on the shell.
15 to 50 psig at the skid is normal. The heater is sized on the lowest pressure the plant delivers at peak, not the boiler setting, and the valve is sized for the start-up load.
On a multi-tank skid the tanks are usually kept warm by a small recirculation heater so the in-line unit only trims. On a single-tank or one-pass skid there is no warm tank and the in-line heater carries the full rise.
Steam side 150 psig at 375 F. Solution side to the CIP pump's shutoff head, often 125 to 150 psig, and HeatX puts that number on the nameplate rather than a generic 100 psig.
Which CIP heaters are product-contact equipment, what the symbol changes, and when it is money wasted.
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Bigger duties, stronger chemistry, flanged ends and a 400 F rating for cleaning loops that never see food.
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What comes back from the circuit at 170 F has to go down the drain at 140 F, and the heat is worth keeping.
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