Contents
About this tool
The Valve Inspection & Testing tool works out, for one valve, which pressure tests API 598 requires, the test pressures, how long each must be held and the allowable seat leakage. It then records each test and judges it pass or fail, ready to print as a test certificate.
Built on API Standard 598, 10th edition (October 2016), the text on file. The 11th edition (2023) is current and has not been compared. The page, the report and this manual say so; the tool will be upgraded when the 2023 text is available. Until then, check any requirement you rely on against the 2023 edition.
Steel-valve shell and high-pressure closure pressures are multiples of the ASME B16.34 rating at 38 °C, which API 598 does not print. The tool offers the Group 1.1 (carbon steel: A105, A216 WCB and similar) standard-class ratings as a preset: 150: 19.6 bar / 285 psig; 300: 51.1 / 740; 600: 102.1 / 1,480; 800: 136.2 / 1,975; 900: 153.2 / 2,220; 1500: 255.3 / 3,705; 2500: 425.5 / 6,170; 4500: 765.9 / 11,110. For stainless, alloy or low-temperature steels choose Enter the rating and type the B16.34 value for that material group.
Quick start
- 1Enter the valve tag, choose the units the purchase order uses (bar or psig), or load a sample.
- 2Section 1: valve type, size, body material, class, ends and seat. Tick backseat, bellows, DBB, lubricated plug or gear-actuated globe where they apply, and any optional tests the purchaser has specified.
- 3Section 2 lists the tests with their pressures and minimum times; Section 3 the allowable leakage.
- 4Section 4: for each test done, enter the pressure held, the time at full pressure, the fluid and the leakage seen. Each row turns pass or fail.
- 5Tick the test-conditions checklist, then Calculate & Save and Print / PDF report.
Which tests (Table 1)
| Valve | Shell | Backseat | Low-pressure closure | High-pressure closure |
|---|---|---|---|---|
| Gate | required | required (with backseat) | required, except NPS ≤ 4 above Class 1500 or NPS > 4 above Class 600: optional | optional, except in those higher classes: required |
| Globe, parallel slide gate | required | required (with backseat) | optional | required |
| Plug | required | n/a | as gate; lubricated plug: optional | as gate; lubricated plug: required |
| Check | required | n/a | optional | required |
| Floating ball | required | n/a | required | optional |
| Butterfly, trunnion ball | required | n/a | as gate | as gate |
- An optional test the purchaser specifies is done in addition (note b). A valve specified as double block and bleed needs the high-pressure closure test (note e) and the DBB test of 6.6, held twice the Table 4 time.
- Backseat tests apply to valves with a backseat, except bellows seal valves (note a). The high-pressure closure test can degrade resilient seats (note c).
- Even where the high-pressure closure test is optional, the valve must be able to pass it (5.4). The pneumatic shell test (5.5) is done only when the purchase order asks for it.
Test pressures (Tables 2 and 3)
| Test | Steel and nonferrous | Iron |
|---|---|---|
| Shell | 1.5 × the 38 °C rating, rounded up to the next bar (or 25 psig); Class 800 the same (API 602) | ductile 150: 26 bar / 400 psig; 300: 66 / 975. Gray 125: NPS 2–12 25 / 350, 14–48 19 / 265; gray 250: NPS 2–12 61 / 875, 14–24 37 / 525 |
| High-pressure closure and backseat | 110 % of the 38 °C rating | check valves: Table 3 values (e.g. cast iron 125, NPS 2–12: 14 bar / 200 psig) |
| Low-pressure closure and backseat | 5.5 ± 1.5 bar (80 ± 20 psig), air or inert gas | same |
| Butterfly high-pressure closure | 110 % of the design differential pressure | — |
| Gear-actuated or power-operated globe | 110 % of the design differential pressure used to size the operator | — |
| API 609 Category A butterfly shell | 1.5 × the maximum CWP | — |
| Pneumatic shell (5.5) | 110 % of the 38 °C rating, no visible leakage | — |
Because the shell pressure rounds up in the unit system used, bar and psig results can differ slightly (Class 300: 77 bar = 1,117 psig, but the US figure is 1,125 psig). The tool converts your entries when you switch units and judges them against the requirement in the new units.
Durations and leakage (Tables 4 and 5)
| Size | Shell | Backseat | Closure, check | Closure, other |
|---|---|---|---|---|
| NPS 2 and smaller | 15 s | 15 s | 60 s | 15 s |
| NPS 2½ – 6 | 60 s | 60 s | 60 s | 60 s |
| NPS 8 – 12 | 120 s | 60 s | 120 s | 120 s |
| NPS 14 and larger | 300 s | 60 s | 120 s | 120 s |
- Time is counted from when the valve is fully prepared and under full pressure.
- Resilient seats: no leakage. Metal seats other than check valves: 2 × NPS drops/min (liquid) or 4 × NPS bubbles/min (gas), with 0 for NPS 2 and smaller. Metal-seated check valves: 3 × NPS cc/min (liquid) or 0.042 × NPS m³/h (1.5 × NPS ft³/h) gas. Sizes over NPS 48 and untabulated sizes use these formulas (note c).
- 0 drops means no visible leakage for the test duration; 0 bubbles means less than one bubble in it. 1 mL = 16 drops = 100 bubbles.
- Nonmetallic (e.g. ceramic) seats are judged at the metal-seated rate (5.9.2.2); reduced-bore valves by their NPS (5.3.3).
- Shell and backseat: no visible leakage. Adjustable stem seals may weep in the shell test without rejection (5.9.1.3).
The test record
- Each row checks the pressure held against the minimum (the low-pressure tests must sit inside the 5.5 ± 1.5 bar band), the time against Table 4, and the leakage against Table 5 for the fluid used.
- Hover over a result for the reason. The summary gives the overall result: passed when every required test is recorded and passed, failed if any fails, otherwise incomplete.
- The test-conditions checklist covers 4.5.1, 5.2, 5.6 and 6.1 – 6.6: casting examination, test fixtures, fluid and temperature, chloride limit for stainless, trapped air, coatings, sealant, closing force and the procedures for each test.
Saving and the report
- Fill in Identification (company, tank or item ID, location) and the record type: Just for research stays private to you; Official is visible to your company.
- Calculate & Save stores the inputs and results in the
valveTestCalcscollection. - Print / PDF report opens a printable page of everything on screen: identification, the standard and edition, each section’s inputs and results, and any notes. Use Save as PDF in the print dialog. The report prints the plan, the chart of pressures against the rating, the record with reasons, and the edition note.
Limits
- 10th edition (2016) basis; the 11th edition (2023) has not been compared.
- B16.34 ratings other than the Group 1.1 preset must be entered; special-class ratings are not built in.
- Valve design, dimensions and supplementary NDE (4.6) belong to the product standard and the purchase order.
- One valve per record. Save each valve under its tag.
Glossary
| Shell test | pressure test above the cold working pressure, proving the pressure-containing parts |
| Closure test | test of leakage past the closed disc, ball, plug or gate |
| Backseat test | test of the seal between the stem and the bonnet with the valve fully open |
| CWP | cold working pressure: the rated pressure at ambient temperature |
| DBB | double block and bleed: one valve with two seats and a cavity vent |