A drawing is useful only after it has been checked against the current pipework. Every feed, return, vent, drain and energy source needs a known control point and an authorised site owner.
Live controls to verify
- Material connections into and out of the vessel
- Mechanical, electrical and stored energy
- Authorised owner for every isolation
The isolation record remains with the live site procedure
Use the site’s live isolation drawing or procedure, not a cleaning form, to identify each line and energy source. Put the valve, device or disconnection beside the name of the person authorised to control it.
The contractor receives the confirmed status, while isolation and return to service remain site decisions.
Use the site’s change procedure for every isolation change
If cleaning exposes a blocked outlet or changes the recovery route, the site pauses the work and uses its authorised change procedure before altering any isolation. The isolation planning guide can organise that discussion without replacing the live procedure.
Can the cleaning contractor decide how the tank is isolated?
The tank owner must control isolation through competent, authorised people and its own procedures. The contractor needs the verified condition so its cleaning plan follows the site boundary.
Why are vents and overflows relevant?
They are connections to the vessel and may affect drainage, atmosphere or cleaning coverage. Their purpose and status belong in the limit review.
Does isolation mean a tank is safe to enter?
No. Entry also requires a suitable confined-space assessment, ventilation, atmospheric testing, supervision, communication and rescue provision. Read the remote cleaning before entry advice when considering non-entry work first.