Commissioning and Startup Training Curriculum

Mod 3 - Cleaning & Flushing

Module from the Commissioning and Startup Training Curriculum curriculum.

Module 3 — Cleaning, Flushing & Drying · Learning Objectives · 1. Select appropriate cleaning method (air blow, steam blow, water flush, oil flush, chemical clean) by system. · 2. Execute steam blow of high-pressure piping with target blow factor. · 3. Apply oil flush procedures for lube and seal oil systems to achieve target NAS cleanliness. · 4. Dry compressor and cryogenic systems to required dew point. · 5. Document cleaning acceptance using target coupons, particle counts, and visual standards. · Cleaning Method Selection

Method	Typical Service	Acceptance Criteria
Water flush	Cooling water, process water	Clear effluent; velocity >3 ft/s
Air blow	Low-pressure utility air, fuel gas	No debris on white cloth target
Steam blow	High-pressure steam piping	Blow factor ≥1.2 of design; polished target
N2 blow	Hydrocarbon service precleaning	Dew point <-40 °F
Chemical clean	Boiler, exchangers with mill scale	No deposits; passivated surface
Oil flush	Lube, seal, hydraulic systems	NAS 1638 Class 7 or better / ISO 18/16/13
Pickling	SS piping with heavy mill scale	Visual + ferric test
Steam Blow — Key Parameters
Parameter	Typical Value
Blow factor	(V_blow / V_design) × (ρ_blow / ρ_design) ≥ 1.2
Puff duration	3–5 minutes per blow
Target material	Polished stainless steel or aluminum plate
Acceptance	<2 dents >1/32 in on last two blows
Silencer	Required; noise <85 dBA at 50 ft
Safety	Barricade 100 ft; hot surface protection
Oil Flush — Cleanliness Targets
System	Target (NAS 1638)	Target (ISO 4406)
Lube oil — turbines / compressors	Class 6	17/15/12
Seal oil — centrifugal compressor	Class 7	18/16/13
Hydraulic — servo valves	Class 5	16/14/11
Hydraulic — general	Class 8	19/17/14
Turbine governor	Class 5	16/14/11
Chemical Cleaning Sequence
Step	Purpose	Chemical / Temp
1. Degrease	Remove oils	Alkaline (Na2CO3/NaOH), 140–180 °F
2. Rinse	Remove degreaser	Demin water
3. Pickle	Remove mill scale / rust	Citric or HCl inhibited, 140–180 °F
4. Neutralize	Stop pickling	Alkaline flush to pH 9–10
5. Passivate	Form protective oxide	Sodium nitrite / citric, 140 °F
6. Dry / preserve	Prevent flash rust	Warm N2 or filming amine
Drying Criteria
System	Target Dew Point
Hydrogen service reactor loop	-40 °F
Cryogenic (ethylene, LNG)	-70 °F
Compressor inlet piping	-20 °F
Fuel gas system	-10 °F
Amine / MEG systems	<200 ppm water
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Source: Commissioning_and_Startup_Training_Curriculum_v1.xlsx · Sheet: Mod 3 - Cleaning & Flushing

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