What this is
What is a line breaking permit?
What is a line breaking permit?
Authorisation to open piping or process equipment, recording what the line contained, how it has been isolated, drained, purged and depressurised, how the opening will be performed, and what protection is in place if something is still inside.
Why is a separate permit needed if the line is locked out?
Because lockout controls the energy sources feeding the line. It does not establish that the line is empty, that pressure has been relieved at the point being opened, or that a low point or dead leg is not holding residual material. Those are separate verifications and they are what this permit exists to record.
Scope
When is a line breaking permit required?
This authorises opening piping or process equipment. Isolation and entry have their own permits.
Use this template when
- Opening any pipework, vessel connection or equipment that has contained a hazardous substance
- Removing valves, instruments, spool pieces or blinds from process systems
- Breaking into lines that have contained pressure, hot material, or oxygen-deficient purge gas
- Work on lines with a plugging or freezing history
- Any opening where the contents or their residual state cannot be assumed
Do not use it for
- The energy isolation permit or lockout, which controls energy sources feeding the system
- Confined space entry, which applies where the opened equipment will be entered
- Hot work permit, where cutting, grinding or welding is involved
- The management of change process, where the work alters the system
- Vessel entry preparation, which is a separate and longer sequence
Compliance mapping
Which OSHA 1910.119 requirements does this satisfy?
Line breaking is governed by process safety practice and general duties rather than a dedicated standard.
| Clause | Requirement | Where it lands |
|---|---|---|
| 29 CFR 1910.119(f) | Operating procedures including safe work practices for opening process equipment or piping | Permit |
| 29 CFR 1910.119(f)(4) | Safe work practices covering lockout, line breaking, confined space entry and control of entry | Gate 2 Isolation and draining |
| 29 CFR 1910.147 | Control of hazardous energy, including stored and residual energy relief and verification | Gate 2 Isolation and draining |
| 29 CFR 1910.146 | Permit-required confined space provisions, where opened equipment will be entered | Gate 3 Breaking controls |
| 29 CFR 1910.119(h) | Contractor obligations including hazard information and safe work practice training | Authorisation |
| CCPS safe work practices | Line opening practice including positive identification, defensive positioning and blinding | Gate 3 Breaking controls |
| 29 CFR 1910.132 | Personal protective equipment appropriate to the residual hazard and the energy that may be released | Gate 3 Breaking controls |
| 29 CFR 1910.119(e) | Process hazard analysis, which should address line opening for the systems concerned | Gate 1 Contents |
What it does not cover
- The energy isolation permit, controlling the sources feeding the system.
- Confined space entry, where opened equipment will be entered.
- Hot work permit, where cutting, grinding or welding is involved.
- Management of change, where the work alters the system.
- Vessel entry preparation, a separate and longer sequence.
How to complete it
How to complete a line breaking permit, step by step
Establish what was in it, prove the condition at the break point, and open it defensively.
What the line carries now, what it has carried, and what could be present as residue: hydrocarbons, caustics, acids, catalyst fines, hydrogen sulphide, purge nitrogen. Service history matters because a line changed over from a previous duty can hold residues nobody currently associates with it, and the safety data sheet for the current product does not describe them.
A gauge upstream of a closed valve or a plug reports the pressure somewhere other than where the flange will be opened. Verification means confirming atmospheric pressure at the point being opened, with a gauge whose calibration is current, and comparing drained volume against calculated line volume rather than accepting that draining occurred.
Pitch, sag, low points, dead legs, instrument tappings and drain legs all hold material that a drain operation does not remove. Small-bore lines that have been leaned on or stood on develop sags that trap liquid. This walk takes minutes and it is what determines whether the line is drained or merely drained from.
Slacken the far side of the joint first so the flange breaks away from the person, stand out of the line of fire, use a spray screen where warranted, and wear protection appropriate to what could come out rather than to what should be present. Where a plug is involved, assume material is held behind it and that clearing it is the release event.
What auditors find
Most common line breaking permit findings
Line breaking findings concentrate on the gap between isolated and empty.
| Finding | Clause | What fixes it |
|---|---|---|
| Lockout treated as establishing that the line is empty. | 1910.147(d)(5) | Isolation controls sources; residual pressure and material require separate verification. |
| Pressure verified upstream rather than at the break point. | 1910.119(f)(4) | A gauge behind a closed valve or a plug reports somewhere else. |
| Line not positively identified at the opening point before permit issue. | CCPS practice | Opening the wrong line is recurring and entirely preventable; identify physically. |
| Low points and dead legs not considered in draining. | 1910.119(f)(4) | Walk the line for pitch and sag; draining is not the same as drained. |
| Plugged line opened without recognising material held behind the blockage. | 1910.147(d)(5) | Clearing the plug is the release event, not opening the flange. |
| Nitrogen purge asphyxiation hazard not addressed. | 1910.146 | Nitrogen has no warning properties; the person sampling can be the person overcome. |
| Opening performed toward the body rather than defensively. | 1910.132 | Slacken the far side first and stand out of the line of fire. |
| Blinds not installed where equipment is removed and the line left open. | CCPS practice | Blind flanges on hazardous service lines when equipment is removed. |
| Permit issued under time pressure without site inspection. | 1910.119(f) | Time pressure produces a permit issued on assumption; inspect the point before issue. |
| Thermal condition not verified before handling. | 1910.132 | Line temperature below safe handling threshold for the material and protection in use. |
Case in point
Case in point: the sample that could not be taken
A safety valve was removed from a low-pressure flare gas header. Atmospheric testing was required for a hot work permit. Two contractor pipefitters removed the valve wearing supplied-air respirators as the permit required. The operator who went to take the atmospheric sample did not wear respiratory protection.
Climbing the scaffold, he was overcome by nitrogen escaping from the open flare line before he could complete the sampling, became disoriented, backed away and briefly lost consciousness. Investigation found elevated nitrogen levels had inadvertently entered the flare system.
The permit had identified the hazard and specified protection for the people doing the work. The person going to measure the atmosphere was not treated as being exposed to it.
The template
The template, field by field
The form exactly as it installs. Every field, option, score and conditional rule is editable, and the links to other templates come with it.
8 sections
- Reference
- SAF-054
- Archetype
- Permit
- Record ID
- PTW-2026-000
- Scoring
- Go or no go
- Direction
- n/a
- Singleton
- No
- Basis
- OSHA 1910.119, process safety practice
- Links
- Links Asset, Substance
- Tags
- Permit, Process safety
- Sections
- 8
- Fields
- 73
- Follow up fields
- 12
- Repeating sections
- 0
- Links out
- 9
Permit
9 fieldsPermit ID*
Auto sequence. Format PTW-2026-00000.
The record's own ID. Other templates point at this value.
Status*
Drives who this goes to next.
- Planned2 pts
- In progress2 pts
- Complete3 pts
- Deferred0 pts
- Open0 pts
- Closed3 pts
- Overdue0 pts
Valid From*
Valid To*
One shift maximum. A new permit is raised for the next shift.
Before You Start
Line breaking releases whatever the line held, at whatever pressure remains. Confirm both before anyone loosens a flange.
Site*
Site ID*
Format SITE-000.
Links to FDN-001 Site ID
Area*
The area within the site.
Exact Location
Drop a pin for anything hard to find.
The work
12 fieldsWork Description*
Work Order ID
Links to MNT-002 Work Order ID
Number Of Workers*
Asset
Asset ID
Format AST-0000.
Links to FDN-002 Asset ID
Risk Assessment
Risk ID
Format RSK-2026-00000.
Links to FDN-012 Risk ID
Contractor Involved*
Contractor
Vendor ID
Format VEN-0000.
Links to FDN-005 Vendor ID
Induction Verified
- Yes2 pts
- No0 pts
- N/Aexcluded from denominator
Method Statement Received
- Pass2 pts
- Partial1 pt
- Fail0 pts
- N/Aexcluded from denominator
Gate 1 Contents
7 fieldsSubstance
Substance ID
Format SUB-0000.
Links to FDN-006 Substance ID
Line Contents*
Ammonia, glycol, caustic, acid, steam, brine, product or water.
- Water4 pts
- Product3 pts
- Brine2 pts
- Glycol2 pts
- Steam1 pt
- Caustic1 pt
- Acid1 pt
- Ammonia0 pts
Operating Pressure*
Operating Temperature C*
Safety Data Sheet Reviewed*
- Pass2 pts
- Partial1 pt
- Fail0 pts
- N/Aexcluded from denominator
Ammonia System Involved*
Ammonia lines require additional controls and respiratory protection on standby.
- No3 pts
- Yes0 pts
Gate 2 Isolation and draining
7 fieldsLine Isolated*
- Yes2 pts
- No0 pts
- N/Aexcluded from denominator
Isolation Permit ID
Links to SAF-050 Permit ID
Line Drained*
- Pass2 pts
- Partial1 pt
- Fail0 pts
- N/Aexcluded from denominator
Line Purged Or Flushed*
- Yes2 pts
- No0 pts
- N/Aexcluded from denominator
Pressure Confirmed Zero*
- Yes2 pts
- No0 pts
- N/Aexcluded from denominator
Vent Point Open And Verified*
- Yes2 pts
- No0 pts
- N/Aexcluded from denominator
Line Cooled To Safe Temperature*
- Pass2 pts
- Partial1 pt
- Fail0 pts
- N/Aexcluded from denominator
Gate 3 Breaking controls
8 fieldsBreak Point Identified And Marked*
- Pass2 pts
- Partial1 pt
- Fail0 pts
- N/Aexcluded from denominator
First Flange Loosened Away From Body*
- Pass2 pts
- Partial1 pt
- Fail0 pts
- N/Aexcluded from denominator
Catch Tray Or Containment Placed*
- Pass2 pts
- Partial1 pt
- Fail0 pts
- N/Aexcluded from denominator
Drain Route Protected*
- Pass2 pts
- Partial1 pt
- Fail0 pts
- N/Aexcluded from denominator
Spill Kit At The Work Point*
- Pass2 pts
- Partial1 pt
- Fail0 pts
- N/Aexcluded from denominator
Respiratory Protection On Standby*
- Pass2 pts
- Partial1 pt
- Fail0 pts
- N/Aexcluded from denominator
Emergency Shower Within Reach*
- Pass2 pts
- Partial1 pt
- Fail0 pts
- N/Aexcluded from denominator
Exclusion Zone Set*
- Pass2 pts
- Partial1 pt
- Fail0 pts
- N/Aexcluded from denominator
Food safety controls
7 fieldsWork In Or Above A Food Area*
Meat and dairy areas need protection before, during and after the work.
Product Removed Or Covered
- Yes3 pts
- Partly1 pt
- No0 pts
Area Screened Off
- Yes3 pts
- Partly1 pt
- No0 pts
Tool And Part Accountability Agreed
Every tool and fastener taken in must be accounted for before release.
- Pass2 pts
- Partial1 pt
- Fail0 pts
- N/Aexcluded from denominator
Food Grade Materials Only
- Yes3 pts
- No0 pts
Post Work Sanitation Required
Sanitation Record ID
Links to QUA-030 Inspection ID
Authorisation
11 fieldsNo Gate, No Start
Every gate above must pass before work begins. There is no partial permit. If anything is unresolved, the permit is not issued.
All Gates Passed*
- Yes2 pts
- No, entry refused0 pts
Reason Not Issued
Issued By*
Issuer Authorised For This Permit*
- Pass2 pts
- Partial1 pt
- Fail0 pts
- N/Aexcluded from denominator
Issuer Signature*
Issue Time*
Accepted By*
Acceptor Signature*
Toolbox Talk Held With Crew*
- Pass2 pts
- Partial1 pt
- Fail0 pts
- N/Aexcluded from denominator
Talk Record ID
Links to TRN-009 Talk ID
Closure
12 fieldsWork Complete*
- Yes3 pts
- No0 pts
Work Suspended
All Persons Accounted For*
- Pass2 pts
- Partial1 pt
- Fail0 pts
- N/Aexcluded from denominator
Tools And Equipment Removed*
- Yes2 pts
- No0 pts
- N/Aexcluded from denominator
Area Left Safe*
- Pass2 pts
- Partial1 pt
- Fail0 pts
- N/Aexcluded from denominator
Guards And Controls Restored*
- Yes3 pts
- No0 pts
Line Reassembled And Pressure Tested*
- Pass2 pts
- Partial1 pt
- Fail0 pts
- N/Aexcluded from denominator
Containment Removed And Waste Disposed*
- Yes2 pts
- No0 pts
- N/Aexcluded from denominator
Permit Cancelled Time*
Cancelled By*
Closure Signature*
Area Owner Signature*
SAF-054 · record IDs look like PTW-2026-000 · Links Asset, Substance
Open in KnowellaRun it with agents
From a document you fill in to a programme that runs itself
The permit authorises opening a system. What fails is the assumption that isolated means empty.
Requires verification at the break point rather than upstream, and holds positive line identification as a gate before issue.
Carries service history and plugging history for the line, and links blinding requirements to equipment removal.
Connects line breaking to interacting permits for confined space, hot work and isolation, so they open and close together.
Ensures contractors receive process hazard information and safe work practice training before the work begins.
This template lives in KnowSafe — safety and compliance. Incidents, hazards, permits, inspections and the critical controls behind them.
Meet KnowSafe→Glossary
Line Breaking Permit definitions and key terms
- Line breaking
- Opening piping or process equipment that has contained a hazardous substance, pressure or energy.
- Positive identification
- Physically confirming at the break point that the line is the intended one, before the permit is issued.
- Dead leg
- A section of pipework with no regular flow, which retains material that draining does not remove.
- Line of fire
- The path a released substance would take, from which the person opening the joint should be positioned away.
- Blind flange
- A plate isolating an open line, installed where equipment is removed from hazardous service.
- Purge gas
- Inert gas, commonly nitrogen, used to displace flammable atmosphere and which creates an asphyxiation hazard.
- Residual energy
- Pressure, thermal energy or material remaining after isolation, requiring relief and verification.
- Double block and bleed
- Isolation using two valves with a vent between, providing verifiable separation from the source.
FAQ
Frequently asked questions about line breaking permit
Why is a separate permit needed if the line is locked out?+
Because lockout controls the energy sources feeding the system and does not establish the condition at the point being opened. A documented incident pattern involves a correctly executed lockout, locks applied per procedure, and residual pressure remaining behind a plug that released when a flange was opened below it. Isolation and de-energisation are different verifications.
Where should pressure be verified?+
At the point being opened. A gauge upstream of a closed valve, a partially closed valve with seat leakage, or a blockage reports the pressure at a different location. Verification also means confirming the gauge's calibration is current, because an instrument reading zero because it has failed reads the same as one reading zero because the line is empty.
What does walking the line achieve?+
It finds low points, dead legs, instrument tappings and sags where material collects and which a drain operation does not clear. Small-bore lines that have been leaned on develop sags holding liquid. Comparing drained volume against calculated line volume tests the same question numerically, and the two together are what distinguish drained from drained from.
Why is nitrogen particularly dangerous here?+
Because it has no warning properties. An oxygen-deficient atmosphere produced by nitrogen cannot be smelled and produces no breathlessness, since the urge to breathe responds to carbon dioxide rather than oxygen. A person can walk into it and lose consciousness without recognising anything. The person taking an atmospheric reading needs the same protection as those doing the work.
How should the joint be opened?+
Defensively. Slacken the far side of the joint first so it breaks away from the person, stand out of the line of fire and upwind where relevant, use a spray screen where warranted, and select protection for what could be released rather than for the nominal contents. Where a plug is present, treat clearing the plug as the release event.
Keep going
Related templates and programmes
Industries this is written for
Programmes this belongs to
Used together in Lockout and Tagout
Audit Finding Record
Records a single audit finding with its evidence, clause reference and classification
Lockout/Tagout Procedure (Machine Specific)
Sets out exactly how to isolate a specific machine, listing every energy source and isolation point
LOTO Periodic Inspection
Checks that a specific energy control procedure is being followed correctly in practice
Energy Isolation Verification
Records the physical test proving stored energy is gone before work begins
Group Lockout Record
Records a group isolation where several people work on one machine under a single lockout
Lock Removal Authorization
Authorises removing a lock when the person who applied it is not available
More in Permits
Hot Work Permit
Controls welding, cutting, grinding and any work that makes sparks or heat
Confined Space Entry Permit
Controls entry into tanks, pits, silos and other confined spaces
Energy Isolation Permit
Controls work where machinery must be shut down and locked out
Working at Height Permit
Controls work above the height set by local rules where fall protection is needed
Excavation Permit
Controls digging and trenching, including checks for buried services
Electrical Work Permit
Controls work on or near live electrical equipment where it cannot be de-energised
Written and reviewed by
Siddarth Singh
Founder & Chief Executive Officer, Knowella
Certified Safety Professional and industrial and systems engineer with more than a decade inside food supply chain, freight and manufacturing operations. This page was written against the current text of the standards it cites, not against secondary summaries of them.
- Certified Safety Professional (CSP), Board of Certified Safety Professionals
- MBA, University of Chicago Booth School of Business
- MS and BS, The Ohio State University, Industrial and Systems Engineering
- Six Sigma Black Belt
Sources and last review. Reviewed 16 August 2026 against:
- 29 CFR 1910.119, process safety management, particularly (e), (f) and (h), OSHA
- CCPS safe work practices, line opening guidance, AIChE
- US Chemical Safety Board safety bulletin on hazards of nitrogen asphyxiation
- 29 CFR 1910.147, control of hazardous energy, OSHA
- 29 CFR 1910.146, permit-required confined spaces, OSHA
This page is general guidance, not legal advice. Confirm requirements with your jurisdiction’s regulator.