Identify field pressure gauges and report unreadable or damaged indications

Match the instrument to the measured equipment

Before recording a number, establish which equipment the gauge measures. A nearby pipe does not prove that it indicates the pressure in the adjacent vessel. Match the field identification plate to the operating record and distinguish the locations of similar gauges. If identification is obscured or illegible, ask operations instead of filling in a name from memory.

Choose an observation position on the normal access route. Do not climb pipework or supports or squeeze between equipment to read the dial. Record an unreadable installation position and request a safe way to check it. Also establish whether the instrument is in service, under maintenance or awaiting verification, because that status affects the meaning of its reading.

Do not identify a record entry by similarity of readings. Different measurement points remain different records even under similar operating conditions. If the mapping is uncertain, hold the numerical entry and record the location and identification condition. People sharing rounds should agree on the same instrument before interpreting later differences.

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1. Dial: distinguish whether the unit, scale and pointer can be read.
2. Metal casing: record visible deformation and damage around the window edge.
3. Instrument connection: report visible damage or wet traces without touching it.
4. Identification plate: match the recorded instrument to its field identity.

Separate the legal scope from the instrument’s role

Article 273 of the occupational safety rules addresses instruments needed to detect abnormal conditions in special chemical equipment meeting specified criteria. Its substance, quantity and equipment conditions do not create one universal gauge requirement for all pipes. Refer an uncertain installation basis to the team holding the equipment and applicability records; report the actual instrument identity and display condition accurately.

KOSHA GUIDE B-E-8-2026 connects instrument selection, installation and use. Presence of a gauge, suitability of its range and correct operation require different evidence. Keep the operator’s reading, instrumentation verification and isolation needed for maintenance distinct, and link each to its own check record rather than combining them into a single normal-status entry.

Selection records must correspond to the instrument actually installed. Similar appearance does not justify using the old record after replacement. Ask the records owner to confirm the correspondence and mark outstanding items. Separating visible observations from documentary checks helps prevent missing replacement history or applicability from being treated as normal.

Record units and readability separately

Identify the unit and scale range before reading the pointer. A number without its unit can lead to false comparisons between gauges. Where several scales appear, identify the scale used. If glare or a cloudy window prevents a reliable reading, record that limitation rather than copying a previous round’s value into the gap.

Seeing the pointer is different from establishing that its value is trustworthy. Record visible oscillation, an off-scale position or a pointer that does not change during observation, together with the observation time. Do not tap the casing or turn adjustments to diagnose it. Inform operations so the observation can be compared with operating conditions, and refer instrument integrity to the instrumentation team.

Do not construct a value from fragments of a scale and an uncertain pointer position. Explain viewing conditions that may change the reading and request verification. Keep the observation time so a later reading can be distinguished. On rechecking, separate a changed value from the earlier readability problem rather than treating that problem as evidence of a process change.

Locate window and casing defects separately

Record clouding or cracks in the window separately from dents or corrosion on the casing, while also noting readability. Describe only what can be distinguished safely and do not loosen a cover to see further. A photograph should identify both the instrument and the defect without crossing an access restriction. Leave areas hidden by glare explicitly unverified.

Cleaning methods depend on the instrument material and surrounding substances. Do not scrape the window or spray cleaner merely because it might improve the view; first report what prevents reading. The field instrumentation checklist in the KOSHA practical guide distinguishes deterioration from indication condition, helping keep display problems and physical damage from being merged into one entry.

Locate visible window or casing damage precisely. If an overall photograph does not locate the defect, describe the direction visible from the safe observation point. Do not invent a replacement threshold from apparent damage size. Keep obscured areas and an unseen rear surface unverified so the next inspection has a clear remaining scope.

Observe connections and supports without handling them

From a safe position, look for changed alignment, damage or wet traces at the visible connection, tubing and support. Visibility does not reveal the pressure or fluid condition inside, so do not tighten a fitting or rotate the gauge. If leakage is suspected, move away and notify operations instead of approaching to smell or touch it.

Distinguish support defects from dial defects and identify the affected connection. Describe apparent casing rotation or visible changes to a support so instrumentation and maintenance can define their checks. Record traces as observations, not a confirmed leak diagnosis. Any dismantling or connection inspection must move to work prepared for the substance and pressure hazards, with the required authorization and precautions.

Where tubing is fitted, distinguish visible support locations without entering restricted space. Report materials pressing on the tubing or interfering near a support. If removal could disturb an instrument connection, notify the team coordinating the work before moving anything. Simultaneously observed support changes and pointer movement do not establish a common cause.

Report indication problems with operating context

Give operations the instrument identity, location, unit, observation time and any reason the indication could not be read. A difference between a local gauge and another display does not establish which is wrong. Their measurement points, update times and operating context must be checked. Identify the displays compared and describe the observed difference directly.

Separate who will check the process state from who will check the instrument. Mark unverified readings so they are not treated as normal values, and identify the location and safe access conditions for further observation. If imminent danger is suspected, move to safety and alert the emergency response system before completing routine round records.

If the recipient cannot visit immediately, check that location and access information are complete. A cropped pointer photograph may omit the unit or identity. Send both identification and indication condition and establish how the response will return. If asked to observe again, reassess changed access conditions rather than assuming the previous position remains safe.

Keep observation distinct from maintenance clearance

A low reading or a stationary pointer does not prove that the equipment is free of energy. Connection to the work point, blockage, isolation and other pressure sources require separate maintenance preparation checks. Supply observations to that process, but do not use the gauge indication alone to proceed with opening a flange or pipe.

If instrumentation decides calibration or replacement is needed, coordinate the instrument range, service conditions and management of the indication during work with operations. Observers must not redraw graduations or move normal-position marks themselves. Any temporary indication or substitute instrument needs an authorized management status that tells the next round whether the old reading conditions still apply.

Make the current work status visible for an instrument under maintenance preparation. An indicated value does not establish completion when the verification scope is unknown. Link the boundaries agreed by operations and the work team to the record, and distinguish a request to observe a display from a maintenance-readiness check. Reconcile the task if its purpose changes.

Leave a clear status for the next round

Separate identification, scale readability, external defects and connection observations instead of labeling the whole instrument simply good or bad. A readable value awaiting accuracy verification calls for a different follow-up from an unreadable window. Distinguishing completed checks from outstanding ones reduces the chance that the next person fills a gap by guessing.

After receiving a completion report, check that changes to instrument identification and indication are reflected in the record. Reconcile a replacement instrument’s changed unit or range before reusing the previous recording format. Link reinstatement evidence and remaining restrictions to the next round, and retain difficult viewing positions or recurring obstructions for improvement review.

Link findings to the corresponding action results. A later replacement record alone may not resolve an original identification problem. Match each initial item to its verification outcome and retain outstanding checks. Clear locations and remaining contacts help the next observer check the present condition instead of copying the previous judgment.

Related reading

• Residual pressure and trapped contents: checks before maintenance
• Verify pressure-relief protection routes and hand over status

Original sources

• Occupational safety rules — Article 273
• KOSHA GUIDE B-E-8-2026 — Sections 4 and 7.2, printed pages 5, 31–32
• KOSHA Practical Guide 69 — printed page 176