Survey-led programme versus blanket treatment of every valve

1. What each approach involves

A blanket programme sends a crew along a fixed route. Every valve receives cleaner, lubricant or sealant on the same cadence. Nothing about the route depends on how any single valve behaves.

A survey-led programme works in the other direction. A condition survey walks the population first and records how each valve operates. Treatment then follows the findings, valve by valve, as part of wider online valve maintenance.

The tools and products are the same in both cases. The difference is the decision step. One approach treats first and records later, and the other records first, then treats what the record justifies.

2. Where blanket treatment still makes sense

Blanket treatment is not a lazy option, and it fits some sites well. Small populations leave little for a survey to sort. Uniform duties help too. One valve type and one service make every valve a fair candidate.

Warranty periods often point the same way. Reported operator practice is a top-up twice a year, of about one eighth of system capacity. Quarterly top-ups are common during warranty periods. These are habits, not rules, and OEM terms differ.

Blanket rounds also keep crews familiar with every valve location, which has value on large sites. The approach weakens when the population is varied. It also weakens when many valves no longer need the visit.

3. The waste a survey removes

The case for surveying rests on how valve problems distribute. A risk-based valve integrity study published by Valve World gives one picture from upstream and midstream sites. It reported 61 per cent of failures as passing and 28 per cent as seized. External leakage and other causes made up the small remainder. Distributions vary by population, so read this as a shape, not a promise.

A fixed round then spends most of its materials and hours on healthy valves. Cleaner and sealant enter valves that showed no need for them. Crews open fittings that a survey would have left closed. Every opened fitting is a small new leak path.

Over-injection carries its own risk. Sealant forced into a valve that holds well can interfere with later operation. A survey-led round buys materials against evidence, not against the calendar.

4. What the survey records, and why

A survey is worth no more than its paperwork. Useful entries cover the valve tag, its line and its service. They record how it operated and the condition of its injection fittings. They also note symptoms seen at the time. Passing may be indicated by a pressure rise across a closed valve.

Screening evidence is not proof. A pressure rise or a sound suggests a seat leak and points to the next step. The confirming step is a seat-leak test under agreed conditions.

The records then serve two purposes. They build the treatment list for the visit. They also feed longer-range planning that separates repeated failures from one-off events. A professional survey keeps both outputs in one place.

5. How to decide between them

The choice is a site decision, and the inputs are mostly local. A short sequence keeps the comparison honest:

1. List the population, its valve types, and the variety of services it handles.
2. Check what warranties, standards and site rules require, and by when.
3. Survey a sample, or the valves that matter most, before committing to either approach.
4. Settle the record format: tags, findings, injections, test results and dates.
5. Weigh the survey cost against the materials, hours and access saved on the round.

Steps like these turn a preference into a decision with evidence behind it. They also show where the two approaches cost about the same. That is worth knowing before the debate starts.

6. The honest limits of both

Neither approach fixes what injection cannot fix. A worn ball, a damaged seat or a cracked body needs workshop repair or replacement. The survey does its job by naming those cases early. It stops the round from hiding them year after year.

Where the programme does recommend injection, the usual gates apply. Fittings must be sound, and the design and service must suit injection. The permit-to-work must also allow the job. OEM documents, where they exist, set limits and warranty terms worth consulting.

Our field teams run both shapes across the Middle East, Asia and Africa, and the pattern holds. Read the wider framing in preventive versus corrective maintenance. A survey-led programme is prevention aimed at named targets, and that aim is its whole value.