KO Pot Inspection Checklist
A structured inspection of the KO Pot to evaluate vessel condition, valve functionality, and separation performance, ensuring the equipment operates safely and reliably within the process system and remains compliant with applicable inspection and safety requirements.
Envent Corporation
08/26/2026
KO Pot Inspection Checklist
This procedure ensures that the KO (Knockout) Pot is systematically inspected for vessel integrity, drain valve functionality, level indicators, pressure relief devices, and inlet and outlet connections, maintaining safe and effective liquid and vapor separation performance, preventing carryover or pressure-related incidents, and supporting compliance with applicable process safety and equipment inspection standards.
Equipment Information
Equipment ID
Date
Location
MAWP (If no MAWP put NA)
PRV Set Pressure (Put NA if no PRV or VRV is installed or required)
Inspector
Safety & Isolation
Vessel isolated and depressurized
Vessel drained and gas-freed
Test area barricaded and posted
External Condition
Vessel shell free of visible damage or deformation
Supports, legs, or skid structurally sound
Connections & Nozzles
Inlet and outlet flanges in good condition, no damage or corrosion to the face of the flange
Drain valve functional and unobstructed
Caps and plugs installed on all open ended connections
All gauges are in good condition and operational.
if the answer is "noneOf [PASS]"
Replace gauges as needed. Verify operability.
Is the sight glass magnetic or have instrumentation?
if the answer is "oneOf [Yes]"
Is the liquid level clearly readable on the level gauge? (scale clean, indicator visible)
Does the level indicator move as the level changes? (not stuck)
Is the level gauge free of leaks at the upper and lower connections and the vent/drain?
Is the level gauge free of damage, corrosion, and loose mounting?
Are the level gauge isolation valves fully open? (if fitted)
Do the indicator flags show a clear level line? (yellow = liquid, black = vapor)
MAGNETIC LEVEL GAUGE ACCURACY CHECK
Accuracy verification using a known water volume.
Record the level gauge reading and the inspection result below.
PASS if Within 2″ of 10.78″ FLAG if 2″ to 5″ off FAIL if More than 5″ off
Sight glass tubing is clean and visible
if the answer is "noneOf [PASS]"
Replace or clean as needed.
Are all fittings compatible with the KO Pot metallurgy? SS KO Pots should ONLY have SS fittings, CS can have CS or Galvanized fittings.
Internal Condition (If Applicable)
No excessive corrosion, debris, or sludge inside of the KO Pot.
Verify Demister pad is in place.
Inlet diverter / baffle intact
Relief Valve Status
Verify if the KO needs a PRV or VRV. If no PRV or VRV is Needed select NA.
Verify if the KO needs a PRV or VRV. If no PRV or VRV is Needed select NA
if the answer is "oneOf [Yes]"
Relief valve installed and oriented correctly?
Relief valve certification tag legible
Test Date
Next Due
Certification Status
if the answer is "oneOf [No – Expired]"
Replace RV with a RV that has a current inspection. If none in stock, create a work order to have a RV installed and red tag the vessel.
Pneumatic Pressure-Up & Relief Valve Leak Check (If No PRV Select N/A)
PRESSURE LIMIT (CRITICAL) Maximum test pressure = the LOWER of: Normal operating pressure. ≤ 90% of PRV set pressure. ❌ Never approach or exceed PRV set pressure ❌ The PRV must not lift during this check Example: PRV set pressure = 200 psig Max leak‑check pressure = 180 psig (90%)
Connect regulated compressed air source. Confirm Pressure gauge on vessel is functioning.
if the answer is "noneOf [Yes]"
Whip Check installed at Air Connection point.
Using Compressed air, pressure increase slowly in stages (25%, 50%, 75%). Final target pressure (≤ 90% PRV set). Pause at each stage for: Audible leak checks and Visual observations.
Final pressure held for minimum 10 minutes
Leak detection solution applied at
Relief valve shows no leakage, bubbling, or or pressure drop off?
Relief valve did not lift or chatter?
Test Pressure Used
Confirm Pressure Limits
Pressure reduced slowly and controlled
Vessel fully depressurized to 0 psig
Acceptance & Disposition FAIL (ANY of the following) Continuous bubbling Pressure slowly decays Audible passing through PRV PRV lifts or chatters A failed PRV shall be removed from service and replaced or recertified. PASS Pressure remains stable No visible bubbles No audible leakage PRV does not lift or simmer
Pneumatic leak check results acceptable
Relief valve acceptable for continued service
Return to Service
Lid is intact, gasket, all bolts are in good condition?
if the answer is "noneOf [PASS]"
Replace and install new componenets as needed.
KO Pot approved for return to service and green tagged?
Corrective work order required
Inspector Comments
Comments
Inspector Signature
By signing below, I agree that I have performed and completed the KO Pot inspection above, and I have recorded the results accurately.
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Source: Envent Corporation (Community Member)