API TES flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Confined space definition

A space large enough for entry, with limited entry/exit, not designed for continuous occupancy; tanks meet this definition and require entry controls.

Entry permit validity

A permit authorizes entry only for the tank, task, personnel, and time stated on it; any change in conditions requires re-evaluation and a new or amended permit.

Atmospheric testing order

Test oxygen first, then flammables (percent LEL), then toxic gases; testing in this order prevents misreading flammables in an oxygen-deficient or enriched atmosphere.

Acceptable oxygen range

Entry atmosphere must contain 19.5 to 23.5 percent oxygen by volume; below is oxygen deficient, above is oxygen enriched and increases fire risk.

Flammable entry limit

Flammable gas or vapor concentration must be below 10 percent of the lower explosive limit before entry and maintained there during occupancy.

Attendant duties

The attendant stays at the entry point, maintains continuous communication with entrants, monitors conditions, and summons rescue without entering the space.

Entry supervisor role

The entry supervisor verifies isolation, atmospheric results, and rescue provisions, authorizes entry, and cancels the permit when work ends or conditions change.

Non-entry retrieval

Rescue by harness and lifeline from outside the space; preferred because it avoids exposing additional people to the hazard.

Continuous monitoring rule

When residue, sludge, or adjacent operations can change the atmosphere, monitoring must be continuous or repeated at defined intervals, not performed once.

Communication requirement

Entrant and attendant must maintain continuous contact by voice, radio, or signal; loss of communication requires the entrant to exit immediately.

Line isolation by blinding

All piping to the tank is physically disconnected or blinded, or double block-and-bleed is used, so no product or gas can enter during occupancy.

Lockout/tagout for tanks

Mixers, agitators, pumps, and other energy sources are locked and tagged out before entry so they cannot be energized while people are inside.

Permit cancellation triggers

Entry ends and the permit is cancelled when the task is complete, a shift ends without handover, or atmospheric or process conditions change.

Atmospheric test record

Each test result is logged with time, location, instrument identification, and tester name so conditions can be verified and trends detected.

Oxygen enrichment hazard

Oxygen above 23.5 percent makes clothing and materials burn vigorously; it is caused by leaks or improper use of oxygen for ventilation.

Rescue plan elements

A rescue plan names trained rescuers, retrieval equipment, communication, and access route, and is verified before any entrant goes inside.

Cleaning sequence for tanks

Isolate, drain, purge or ventilate, test the atmosphere, and only then allow entry; cleaning inside begins after the atmosphere passes.

Ventilation prohibition

Pure oxygen must never be used to purge or ventilate a tank; it creates an oxygen-enriched, fire-prone atmosphere.

Sludge disturbance hazard

Agitating sludge or scale can release trapped hydrocarbons or hydrogen sulfide, so the atmosphere is retested after cleaning begins.

Retrieval system rigging

Harness and lifeline are rigged and anchored before entry so an incapacitated entrant can be lifted out without a rescuer entering.

Intrinsically safe equipment

Lighting, tools, and instruments used in a potentially flammable atmosphere must be rated and approved for that hazard class.

Respirator versus ventilation

Respiratory protection protects the wearer only; it does not make the space safe, so ventilation and atmospheric testing are still required.

Hydrogen sulfide properties

H2S is heavier than air, accumulates in low areas of tanks, deadens the sense of smell at higher concentrations, and is measured by direct-reading instruments.

Static and bonding in cleaning

Washing or steaming tanks that held flammables requires bonding and grounding and control of hot surfaces to prevent ignition of vapors.

PPE selection basis

PPE for tank cleaning is chosen from the hazard assessment: chemical exposure, atmosphere, and physical hazards determine suit, gloves, and respiratory protection.

Standby rescue team

When non-entry retrieval is not feasible, a trained rescue team with equipment is staged at the tank before entry begins.

Hot work inside tanks

Welding or cutting inside a tank requires a separate hot work permit, gas-free verification, and continuous monitoring in addition to the entry permit.

Gas-free certification

A gas-free certificate documents that atmospheric tests meet entry criteria at a stated time; it supports but does not replace the entry permit.

Purging versus inerting

Purging displaces vapors with air to make the space breathable; inerting replaces air with inert gas to prevent fire and is not breathable, so entry is prohibited.

Entry point control

The entry point is controlled so only authorized entrants pass, and equipment, hoses, and cords are routed so they do not obstruct egress.

Low-point testing

Atmospheric samples are taken at low points as well as at mid-height because heavier-than-air gases such as H2S collect near the tank floor.

Evacuation trigger

Entrants exit immediately if monitoring alarms, ventilation fails, communication is lost, or the attendant orders evacuation.