When a plant is acquired or newly commissioned, its valve records are often incomplete or inconsistent. The sound sequence is to close the records gap, run a baseline condition survey across the population, then rank valves by criticality and observed condition before spending on treatment. Suspect valves need a confirming seat-leak test under agreed conditions before any repair decision.
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Taking over new assets: valves in acquired or commissioned plants
Acquired and newly commissioned plants rarely arrive with complete valve records, so the first job is a baseline survey.
1. Why handovers leave a records gap
An acquired plant arrives with the valves it has, not the valves the dossier describes. Common causes of the records gap include OEM manuals lost between owners, as-built drawings never updated, and commissioning data left with the contractor.
Newly commissioned plants have a different gap. Commissioning records show the valves were acceptable at handover. They say little about condition after the first months of service.
The practical effect is the same: nobody can say which valves were lubricated, when, or with what. That uncertainty, not valve age, defines the takeover problem. Warranty periods may also be running, with nobody tracking them.
2. What the baseline survey covers
The practical answer to missing records is a baseline survey of the whole population. A valve condition survey walks down the plant and verifies tags against the line list. It records what is actually installed, valve by valve.
- Identity: manufacturer, type, size, pressure class, and whether injection fittings exist on stem and body.
- Condition: ease of operation, visible stem or body leakage, and the state of fittings and caps.
- Context: the service, the isolation role, and access for people and equipment.
Findings at this stage are screening evidence only. A valve that passes downstream pressure, or sounds open to flow, suggests a seat problem. It does not confirm one. Confirmation comes from a seat-leak test under agreed conditions, arranged for the valves that matter most.
A first survey can be done in house or by a specialist survey team. Valves with no service history need the same walkdown, with wider margins.
3. Ranking valves when data is thin
The survey produces a ranked worklist, not a uniform one. Two axes are enough: how much the valve matters, and what condition it is in.
- Critical valves on main process lines, flare headers and isolation duties come first, whatever their condition.
- Valves that operated stiffly, passed or leaked during the walkdown come next.
- Everything else, cycled on a routine, comes last.
Condition data helps set expectations. A risk-based valve integrity study of upstream and midstream sites, published by Valve World, reported the common failure modes. It found 61 per cent passing, 28 per cent seized, and 6 per cent leaking externally. Distributions vary by population. Treat the figures as a planning aid, not a forecast for your plant.
Regulation sets a floor, not a programme. India's PNGRB T4S rules for city gas require annual tests for regulators, slam-shut and relief valves. They stay silent on mainline ball valve intervals, so the new owner must set them from survey evidence.
4. Where in-service treatment fits
Many takeover valves can be treated in service, without a shutdown, once three gates are passed. The injection fittings must exist and be in good condition. The valve design and service must suit injection. Site rules and the permit-to-work must allow the job. Where OEM documentation exists, consult it for limits and warranty terms.
Clean, lubricate and seal work then proceeds valve by valve. Cleaner loosens old deposits, lubricant restores smooth operation, and sealant addresses seat leak. Each is injected in measured amounts, within fitting and equipment ratings. The crew watches the pressure response and stops if it climbs without movement.
Injection is not the answer to everything. A valve seized solid, damaged internally or leaking from the body needs a proper assessment, and often removal or replacement. A stiff valve that improves with cleaner and lubricant is the suitable case.
5. The record to build in year one
The survey closes the records gap only if its results are kept. Build the register the seller never provided. Record the baseline condition, the test results, every injection with its date and amount, and the spare fittings held on site.
- Update the register at the moment of treatment, not from memory later.
- Schedule the next intervention from each valve's response, not from a generic calendar.
- Feed any later failure back into the plan through a structured review.
Within a year, the population moves from unknown to managed. The register then becomes the input to an integrity management programme. For older fleets, a separate ageing population strategy sets inspection and replacement horizons. Many sites hand the routine to a maintenance contract, so the record stays continuous across staff changes.
Common questions
New plant valve handover questions, answered directly
What should we check first when taking over a plant with valves?
Start with the records you actually hold, then walk the plant. A baseline survey verifies what is installed, the state of fittings, and which valves operate, pass or leak. Screening findings point to the valves that need a confirming seat-leak test.
How do you set valve maintenance intervals after an acquisition?
Set intervals from survey evidence and criticality, not from habit or the previous owner's calendar. Critical isolation valves come first, then valves that showed faults on the walkdown. Where standards are silent, the new owner must set and justify the intervals.
Can acquired valves be serviced online?
Often, in suitable cases. The valves need injection fittings in good condition, a design and service that suit injection, and a permit that allows the work. Valves seized solid or leaking from the body need assessment or replacement instead.
Do commissioning records count as a maintenance history?
No. Commissioning tests show the valves were acceptable on the day of handover. They say nothing about lubrication, cycling or seat wear after months in service, so a baseline survey is still needed.
Taking over a valve population?
Send the plant valve list. An engineer replies within 24 hours.
Include valve types and sizes, line service, known problems, and any records received. We will suggest where a baseline should start.