This hub explains why installed valves fail, how faults are confirmed, which maintenance routes remain credible, and when isolation or replacement is required.
Knowledge hub
Online valve maintenance knowledge
Clear answers that help operators find faults and choose the next step.
Pillar topics
Six guide groups for valve decisions
Each group answers one operating question with clear examples from field work.
Online valve maintenance fundamentals
Learn how online maintenance treats valves in live, pressurised pipelines. The guides explain when to use cleaners, lubricants and sealants.
Read the guidePassing valves: diagnosis and repair
Learn why a closed valve leaks, how to confirm the fault, and which repair routes remain credible.
Read the guideValve sealant injection explained
See how non-hardening sealants support damaged surfaces while the valve can still move. The guides also explain why controlled high-pressure injection equipment matters.
Read the guideHard-to-operate valves
Learn how dried residue, dirt and poor lubrication can restrict valve movement. The guides explain checks to make before choosing cleaner or lubricant.
Read the guideLive leak sealing and fugitive emissions
Learn about stem and body leaks while equipment stays installed and pressurised. The guides link maintenance choices with lower fugitive emissions.
Read the guideValve integrity management
Build a planned routine from surveys, treatment history and operating results. The guides show how clear records support maintenance across many valves.
Read the guide
All guides
Every guide, grouped by topic
Each guide is written to the same reviewed engineering standard.
Pillar guides (5)
Symptoms and diagnosis (19)
- Actuator torque trip: check valve mechanics first
- Ball valve passing: debris, seat damage or a false sign?
- Body and bonnet joint leaks on live valves
- Buried and chamber valves: why they deteriorate faster
- Cavity pressure in ball valves: the symptom explained
- Double block and bleed will not hold: which valve passes
- Downstream pressure rising after isolation
- Dry-gas valve leakage: lubricant loss, seal behaviour and compatibility checks
- Gate valve will not seal: causes and fixes
- Handwheel will not turn: find the fault before torque
- Sand contamination in wellhead and pipeline valves: ingress, wear and flushing limits
- Sectionalising valve fails its closure test: now what?
- Seized plug valve: diagnose before applying force
- Stiff gear operator or stiff valve: telling them apart
- Valve fails the bubble test: severity and next steps
- Valve passing after hydrotest: why new lines leak
- Valve seized after years idle: why unused valves fail
- Valve stuck mid-travel: causes of incomplete stroke
- Valve torque rising year on year: what it means
Procedures and practice (11)
- Buttonhead injection fittings: identification, ratings and checks
- Condition-based sealant top-up planning: service severity, leakage history and inspection triggers
- Estimating valve sealant quantity under uncertainty
- Exercising live valves: purpose, limits and stop-work conditions
- Injection pressure versus line pressure: safety rules
- Online sealant injection: pre-job checks, execution stages and acceptance evidence
- Per-valve service records: what to log and why
- Pre-injection safety check: ratings, barriers and stop-work conditions
- Valve-cleaner dwell time: controlling factors and how to decide when to retest
- What a valve condition survey covers
- What cannot be fixed online: honest valve repair limits
Products explained (9)
- Avoiding counterfeit valve products
- Sealant selection by seat design, injection system and service medium
- Selecting sealant for temperature service: envelope, excursions and evidence
- Valve cleaner before sealant injection: purpose, limits and compatibility checks
- Valve lubricant versus valve sealant: when each is right
- Valve sealant compatibility: media, elastomers and old product
- Valve-sealant storage and field acceptance: shelf life, contamination and heat exposure
- Why general-purpose grease is not automatically a substitute for valve lubricant or sealant
- Why some valve sealants harden in dry-gas service
Injection equipment (7)
- 10,000 PSI injection equipment: what the rating does and does not permit
- Choosing injection equipment by pressure, volume and field constraints
- High-pressure gun safety rules
- Hoses, couplers and adapters for injection work
- Injection-gun failure signs: repair, pressure testing and retirement criteria
- Keeping sealant guns reliable
- The complete field kit for online valve service
Decisions and economics (6)
- Budgeting valve maintenance across a network
- Building a shutdown-cost case for valve work: cost categories, boundaries and assumptions
- How maintenance can extend valve service life, and where it cannot
- Online valve repair vs replacement: real cost comparison
- The maintenance-free valve myth: a balanced view
- Valve fugitive emissions: leak paths, LDAR evidence and maintenance response
Standards and compliance (8)
- API 598 seat-leakage acceptance criteria: what the test does and does not prove
- API 6D and valve maintenance
- ASME B31.8 on valve maintenance
- ISO 15848: fugitive emissions from valves
- ISO 5208 leakage rates: reading the classes
- Isolation readiness: evidence a sectionalising valve will close and seal
- PNGRB T4S and Indian CGD valve upkeep
- Warranty-period valve care: follow OEM instructions and preserve claim evidence
Industries (5)
Deep technical topics (25)
- After pigging: debris risks to mainline valves
- Baselining valves with no service history
- Can injection fittings be retrofitted to an installed valve? Design, approval and pressure-boundary limits
- Differential pressure and seat sealing: why leaks vary with conditions
- ESD valve partial-stroke testing: what it proves, what it cannot, and what evidence is still needed
- Field seat-leak testing methods compared
- Flooded valve chambers: assessment after water ingress
- Full travel does not prove tight shut-off
- Hydrogen-blend service: seal compatibility, leakage monitoring and limits of existing valve evidence
- Low-temperature valve problems: icing, seal contraction, lubricant viscosity and actuator readiness
- Managing a temporary injected seal
- Obsolete valves with no OEM spares: inspection, repairability and replacement planning
- Over-injection: cavity packing and operational effects
- Planning live valve maintenance: operations gates, SIMOPS, sequencing and contingency
- Preserving stored and spare valves
- Reading a valve survey report: what good evidence looks like
- Reading valve nameplates before maintenance
- Sealant injection has no uptake
- Single-valve isolation, DBB and DIB: what each arrangement actually provides
- Stem packing systems: types and live-adjustment limits
- Through-conduit gate valves: sealing behaviour and maintenance needs
- Valve criticality ranking: consequence, isolation role and evidence quality
- Wet, sour and CO2-bearing gas: corrosion, deposits and seal compatibility in valves
- Why bubbles, sound and pressure decay cannot be converted directly into API 598 or ISO 5208 leakage classes
- Why trunnion and floating ball valve seats leak differently
Field practice (5)
- Leaking or damaged injection fittings on live valves: warning signs, pressure-boundary risks and stop-work limits
- Measuring valve torque in the field: methods and trend value
- Proving isolation before excavation or hot work: the valve's role
- Seat vs stem injection points: what each treats
- Turning valve service records into replacement forecasts
More topics (1)
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Interactive tools
Check your valve in minutes
Two free tools built from reviewed guidance and published study data. No sign-up, and nothing is collected.
Interactive tool
Passing valve screening check
Screen the symptoms, identify what must be confirmed, and find the next safe step.
Run the checkInteractive data
How pipeline valves fail
Explore the four failure modes from published study data. Passing valves formed 61% of faults in the cited study population.
Explore the data
Start with the valve condition
Cannot find your valve problem in the guides?
Send the valve type, operating condition and current symptom. An engineer replies within 24 hours.