The standard defines scope
A product standard defines the valve family, but size, pressure, body type and material coverage can still vary within that standard.
This page separates the standards confirmed in the current catalogs from standard systems that can be reviewed against a requisition, drawing or project specification. It also explains why similar pressure numbers and cross-references do not create automatic equivalence.
A product standard defines the valve family, but size, pressure, body type and material coverage can still vary within that standard.
GB/T, CB/T, CBM, JIS F, DIN/EN, ASME/ANSI and KS V use different bases; a similar number is only a starting point for review.
Product standards, flange standards, class certificates, IMPA codes and ship specifications answer different questions; none replaces the others.
A marine requisition can carry several references at once: the valve product standard, a flange standard, a ship or project specification, and a class requirement. They answer different questions, so they should not be used as synonyms.
What it is: GB/T identifies a recommended Chinese national standard. Older requisitions and drawings may show GB before the /T designation. The complete number and edition, not the prefix alone, identify the product standard.
How to state it: write the full number and year, then add valve type, body type, DN, pressure, material list, medium and temperature.
What it is: Chinese shipbuilding industry standards, widely used for marine valves, fittings and piping components. Newer lists usually show CB/T; older documents may show CB.
How to state it: keep the complete CB/T or CB number, and state connection type, applicable size range, pressure, materials and documentation requirement.
What it is: an older marine standard-number series that may appear on drawings, nameplates and stock lists. It can be the governing product reference or a cross-reference beside GB or CB/T.
How to state it: keep the CBM number exactly as shown, then confirm valve type, size, pressure and material before using it for cross-reference review.
What it is: the Japanese Industrial Standards series for ships and marine equipment. JIS F identifies the marine product standard; JIS B is commonly related to flanges.
How to state it: write the JIS F number, K rating, A/B size callout if used, material, flange drilling, facing and certificate scope.
What it is: European product and flange references used in European ship specifications and owner fleets. Legacy DIN callouts may remain in repair documents even when current documents use EN.
How to state it: provide the DIN or EN number and edition, PN designation, material group, flange facing and drilling, and the project drawing where applicable.
What it is: the American valve and flange system, common on vessels and offshore projects with U.S. technical influence. ASME B16.34 and B16.5 are frequent references for valves and flanges.
How to state it: state Class, NPS, applicable ASME/ANSI references, material group, facing, bore or schedule, design temperature and pressure.
What it is: petroleum-sector references more often linked to oil cargo, process, offshore and higher-integrity piping applications than to general ship-service valves.
How to state it: identify the exact API reference, service, pressure class, material, end connection, trim and documentation requirement.
What it is: British Standard references still found on older vessels, owner standard lists, imperial-size spares and legacy replacement documents.
How to state it: keep the BS number and edition, then add the measured dimensions, material, connection details and certificate requirement.
What it is: Korean ship and marine equipment standards used in Korean shipyard and owner projects, sometimes together with a shipyard specification or class requirement.
How to state it: provide the KS V number, pressure and size callout, material, connection standard and project approval basis.
What they are: international or manufacturer-association references and owner/shipyard specifications that may define additional dimensions, inspection or documentation requirements.
How to state them: send the governing document and revision rather than asking for an open-ended equivalence confirmation.
What they are: ABS, BV, CCS, DNV, LR, NK, KR, RINA and other classification-society documents define certification, survey or approval requirements for a defined product and range.
How to state them: name the society, certificate type, product, size and pressure scope; do not assume a certificate transfers to another valve family.
What it means: numbers such as Q41F-16 identify a valve model or series; they do not by themselves establish the governing marine product standard.
How to state it: use the model as a reference, but also provide the standard, size, pressure, material, connection and application.
| Example | What it tells you | What it does not tell you |
|---|---|---|
| GB/T 584-2008 | A specific marine cast-steel flanged stop-valve standard and edition | The selected body type, DN, pressure rating and material list |
| CB/T 4026-2005 | A specific marine cast-iron flanged gate-valve standard | Whether a JIS F cross-reference is acceptable for the project without technical review |
| CBM 1048-81 | A reference number that may appear beside a GB/T product standard | Automatic material, pressure or flange equivalence |
| JIS F 7364 | A Japanese marine product standard for a flanged cast-iron gate valve | The K rating, size, material and flange drilling unless they are stated separately |
| EN 1092 / PN16 | A European flange-system reference with a pressure designation | Valve type, body material, trim, temperature limit or acceptance for a GB/T valve |
| ASME B16.34 / Class 150 | American valve design and pressure-class references | NPS, material group, end connection, facing, bore and pressure-temperature basis |
| KS V | A Korean marine standard-family prefix | The exact KS V number, valve scope, size, pressure, material and flange details |
| DNV / LR / ABS certificate | A certification, survey or approval requirement | The governing product standard or automatic approval of another valve model |
| IMPA code | A procurement catalogue reference that can help identify a marine store item | A technical standard, material grade, pressure rating or flange dimension |
| Q41F-16 | A valve model designation used on requisitions and stock lists | A governing marine product standard; it must be confirmed separately |
A replacement can be considered only after the original and proposed standards are reviewed together. Similar DN, PN, Class or K numbers do not establish equivalence, and a cross-reference on a stock list does not automatically approve a substitution.
| Check | Why it matters |
|---|---|
| Original and proposed standards | Defines product scope, dimensions and pressure-temperature basis |
| Body and trim materials | Material names alone do not confirm casting grade, seal suitability or class acceptance |
| Size, body type and connection | Determines installation compatibility with the existing piping |
| Flange drilling and facing | Same nominal size and pressure number can still produce different bolt patterns |
| Structure length | Critical for replacement and yard installation |
| Ship, owner or yard specification | May add approved-manufacturer, inspection or documentation conditions beyond the product standard |
| Certificate scope | Type approvals and class certificates apply to defined products and ranges |
Subject: Marine valve RFQ - standard confirmation IMPA code, model or drawing reference: Original standard and edition: Governing ship / owner / yard specification, if any: Valve type: Nominal size: DN / NPS / A-B Pressure designation: PN / Class / JIS K Body and main trim materials: End connection and flange standard: Service medium and temperature range: Classification-society or third-party inspection requirement: Quantity and destination port:
This page supports procurement communication. It does not replace the governing product standard, flange standard, ship or project specification, class rule, certificate scope, IMPA data or approved project drawing.
We review the product page, dimensions, material scope and certificate requirement together, then confirm what can be supplied before quotation.