Confined Space Work Permit

The following rules shall govern specifically those conditions which must be met when a decision is made to permit a hazardous job:

Confined space tank/vessel or excavation entry: visual inspection of inerted vessels.


An entry permit Is required before any person may enter a confined space such as a tank, vessel, or pit/excavation deeper than five (5) feet. Visual inspection of a vessel interior that is inerted or may contain carbon monoxide requires a permit. A ‘vessels is any piece of equipment which must be entered through a manhole or restricted opening. "Entry’ means whenever the plane of the vessel opening, confined space, tank. or excavation is broken.


  1. An entry permit is required prior to entering any confined space (tank, vessel, pit etc.) or excavation deeper than five (5) feet. Sump pits with permanent air blower are excluded.

  2. For any entry permit to be approved, initial monitoring of the space to be entered will be completed to assure a minimum of 19.5% oxygen. “zero” percent combustible vapors. and safe limits of other possible contaminants.

  3. In addition to initial monitoring, continuous monitoring will be done to assure that the above prescribed safe limits are maintained within the space to be entered. A change of conditions within the confined space can occur from the work being performed within the confined space. as well as from other sources.

The blue copy of the confined entry permit will be affixed to the confined space to be entered as part of a sign stating a manhole watcher is required. The work permit will be removed at the end of the job and be handed back to the owning supervisor.

All piping connected to equipment to be entered shall be Isolated to prevent the entry of contaminants or hazardous material while personnel are inside. See A.P. “Blinds Installation and Removals”.

All chemical lines (either liquid or gas), all inert lines, and all live steam lines shall be physically disconnected (with blind flanges over the vessel openings) or shall be blinded with suitable slip or figure eight blinds, as close to the vessel as feasible. All blinds are to be spread on the vessel side.

Water lines and low pressure. low temperature condensate lines (With temperatures below 55 degrees Centigrade) may be isolated by double block valves having an open bleeder connection between. These valves must be danger tagged. Reboiler steam and condensate lines must be double block and bled, and danger tagged.

Ventilation shall be adequate to provide safe breathing air and to remove excess heat. All manholes will be open, all air movers shall be set up to blow out. Only air shall be used to drive air blowers. Portable A/C are permissible when inlet air is not contaminated.