By Capt. Neeraj Bharti, Founder, Master Mariner · Published · 2 min read
"Dark condensate as last cargo: clean or dirty when preparing tanks?"
Condensate sits awkwardly between clean and dirty. Some condensates are light, pale and behave almost like a clean product. Others are darker, waxy and leave residue more like a light crude. When condensate was the last cargo, how you classify it decides how much cleaning the next grade needs, and getting it wrong is a common route to an off-spec claim.
Why condensate is hard to classify
"Condensate" covers a wide range of liquids from gas field production, with very different properties:
- Colour: from water-white to dark
- Wax content: some condensates leave wax deposits, especially in cooler conditions
- Heavy ends: some carry heavier components that cling to surfaces
- Contaminants: some contain sulphur compounds, mercury or other trace components
A "light" label on the cargo documents does not guarantee light residue in the tanks.
Clean or dirty?
The safe working approach: treat condensate by what it leaves behind, not by its name.
- If the tanks show dark residue or wax after discharge, plan as for a dirty previous cargo.
- If the condensate was pale and the tanks are clean after discharge, a lighter cleaning may be acceptable for some next grades.
- Check what the charterer's previous-cargo rules say about condensate for the nominated grade. Some treat it as dirty by default.
Preparing tanks after condensate
- Inspect after discharge for colour, wax and sediment.
- Wash with heat if wax or dark residue is present.
- Flush lines, pumps and coils. Wax can settle in cooler parts of the system.
- Manual finishing, mopping and drying.
- Check for trace contaminants if the condensate had specific components the next cargo is sensitive to.
- Ventilate thoroughly: condensates are volatile.
Safety
Condensates can be very volatile and may contain hydrogen sulphide or other toxic components. Atmosphere testing before entry needs to cover these, and gas-freeing must be complete before manual work.
See the DPP to CPP changeover guide and cleanliness expectations by grade.
How Cleanship helps
We assess tanks after condensate and plan the cleaning for the next grade from our bases at Fujairah and in India. See our DPP and CPP tank cleaning service or contact us.
Sources & further reading
Frequently asked questions
Is condensate a clean or dirty cargo for tank cleaning?
It depends on the condensate. Treat it by what it leaves in the tanks: if there is dark residue or wax, plan as for a dirty previous cargo, and check the charterer's rules for the next grade.
Why can condensate leave wax in tanks?
Some condensates contain waxy components that settle on surfaces and in cooler parts of the cargo system, especially in cooler conditions.
What safety risks does condensate pose during tank cleaning?
High volatility and possible toxic components such as hydrogen sulphide, so atmosphere testing and gas-freeing must cover them before any entry.
Do charterers treat condensate as dirty?
Some do by default for certain grades. Check the voyage instructions and previous-cargo rules for the nominated cargo.
- condensate previous cargo
- dark condensate tank cleaning
- condensate to clean products
- condensate tanker cleaning
- previous cargo condensate
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