What API 682 covers
API 682, "Pumps: Shaft Sealing Systems for Centrifugal and Rotary Pumps", sets requirements for mechanical seals and their support systems in petroleum, natural gas and chemical service. Pump tenders usually call it up from the pump specification or from API 610, which refers to API 682 for seals. The seal is normally bought by the pump maker from a seal maker, so the bid engineer has to pass the seal requirements on and check the answer that comes back.
Categories, arrangements, types and piping plans
| Term | What it describes | In outline |
|---|---|---|
| Category | The seal's intended duty and the testing and documentation behind it | Category 1 for pumps not built to API 610, Category 2 for API 610 pumps, Category 3 the most demanding |
| Arrangement | How many seals there are and how the space between them works | 1: one seal per cartridge. 2: two seals with an unpressurised buffer fluid. 3: two seals with a pressurised barrier fluid |
| Type | The seal design | A: pusher seal with elastomer O-rings. B: metal bellows with elastomers. C: metal bellows with flexible graphite, for higher temperatures |
| Piping plan | The fluid, piping and instruments that support the seal | For example Plan 11 (flush from pump discharge), Plan 52 (unpressurised buffer), Plans 53A, 53B, 53C (pressurised barrier) and Plan 54 (external barrier system) |
Where seal deviations come from
| Item | What to check | Typical deviation or clarification |
|---|---|---|
| Category, arrangement, type | Against the datasheet and owner seal rules | Single seal offered where a dual seal is asked for; different type |
| Piping plan | Plan number and its components | Plan 53A offered where 53B is specified |
| Support system scope | Who supplies reservoirs, accumulators, coolers, instruments and piping | Seal system by others; scope split unclear |
| Instruments | Owner instrument rules, hazardous-area ratings, approved makers | Seal maker's standard instruments differ from owner rules |
| Materials | Face and secondary seal materials for the fluid | Different face pair or elastomer offered |
| Qualification and tests | Qualification test evidence and any extra tests or witness points | Test report covers a similar seal, not the one offered |
| Documents | Seal datasheet, drawings, plan schematic, certificates | Document not offered or late |
Record each gap as one row in your technical deviation list, with the clause, what you offer, a justification and a cost of withdrawal. The pump manufacturers page has a worked example of a Plan 53A against 53B deviation.
How OdysseyGPT helps
OdysseyGPT reads the whole tender package, including the pump and seal specifications, datasheets, requisition and ITP. It checks each requirement against your own seal and pump datasheets, standard specifications and test procedures, and gives each one a status with a quote and page reference. It exports an editable compliance matrix and a deviations & clarifications list. It does not select seals or piping plans, read P&IDs or certify compliance; your engineers decide every open item. See OdysseyGPT for manufacturing.