Defining scope for a multi-valve campaign

1. Build the register before anything else

The register is the foundation of the scope of work. It lists every valve in the campaign, not only the problem valves. Each entry carries the data a provider needs to plan treatment.

1. Tag number, line number and physical location.
2. Valve type, size, pressure class and maker where known.
3. Service: the media and a plain description of conditions.
4. Symptom: passing, hard to operate, seized, or leaking to atmosphere.
5. Injection fittings present, and their condition.

Record symptoms as observed behaviour, not as conclusions. A report that a valve is passing suggests a seat fault, not a proven one. Confirmation comes from a seat-leak test under agreed conditions, such as pressure decay across the closed valve.

Where records are thin, a condition survey builds the register and baseline evidence in one visit. Many sites begin with a pilot group and extend the campaign once results are visible.

2. Rank priorities by consequence, not convenience

Scope needs an order of work. Rank valves by what failure costs the plant, not by which are easiest to reach. A passing valve on a fuel gas isolation line usually matters more than a stiff valve on a low-risk vent.

Common priority bands look like this:

1. Safety and emission critical valves, including relief valve isolation and vent lines.
2. Valves whose failure stops production or forces a shutdown.
3. Valves with passing seats that flare gas or lose product.
4. Stiff or seized valves that still operate but are getting worse.

Write the reason beside each rank. Priorities set the sequence, the crew days and the price, so both sides can see what drives cost. They also give a clear reference point when the plan must change mid-campaign.

3. Gates that decide what treatment is in scope

Before any valve joins the treatment list, it passes simple gates. In-service injection is not possible on every valve, and the scope should say so plainly.

1. Injection fittings are fitted and in good condition.
2. The valve design and the service suit injection of cleaner, lubricant or sealant.
3. Site rules and the permit-to-work allow work on the live line.
4. OEM documents, where they exist, are checked for limits and warranty terms.

Valves built with injection points are designed to be maintained in service. A valve that fails a gate stays in the register but follows another route, such as repair at the next planned shutdown. Writing the gates into the scope keeps exclusions agreed rather than discovered.

Gates also protect the warranty position. Where the OEM sets conditions for in-service treatment, the scope should record them rather than ignore them.

4. Write contingency rules into the scope

Campaigns change once work begins. A valve may not respond to treatment, or the pressure response during injection may suggest a deeper fault. Contingency rules agreed in advance keep these decisions calm and quick.

1. Treatment is applied in controlled amounts within equipment and fitting ratings, watching the pressure response at each stage.
2. Stop-work triggers, such as abnormal pressure rise, end treatment on that valve.
3. A valve that does not respond moves to a proper assessment, or to replacement planning, not to more injection.

Give each valve a stated ceiling of treatment effort in the scope. The campaign report should record what was tried on each valve, and why treatment stopped.

Sequencing, simultaneous operations and fallback plans are covered in planning live valve maintenance.

5. Turn the scope into an enquiry

A scope written this way converts directly into an enquiry. Send the register, the priorities and the site constraints, and an engineer can respond with a plan and a price basis. An engineer replies within 24 hours to a valve problem sent by WhatsApp or the contact form.

1. Send the valve list with symptoms, sizes and fitting details.
2. Ask for the treatment product guide through an enquiry if your own crews will inject.
3. Agree acceptance evidence before work starts, so both sides measure success the same way.

For the wider decision, see our guide to choosing an online valve maintenance provider. A formal tender follows the same structure in writing an RFQ for online valve maintenance. How success will be measured is covered under agreeing acceptance evidence.