Flanges: The 62 GB Records Behind a Pipe Joint

Last updated: 14 November 2026.

Direct answer. China's registry returns 62 records for the term steel pipe flange: 10 current, 52 abolished. The 2010 product-type series is entirely dead; the live set is the 2019 two-part split, GB/T 9124.1 for PN and 9124.2 for Class, plus matching gasket and bolt parts issued in 2020 and 2023.

A flange looks like the simplest item on a bill of materials and carries one of the messiest standard trails. The Chinese registry returns 62 records for steel pipe flanges, and 52 of them are abolished. A buyer who quotes "GB flange" from a twenty-year-old drawing is quoting a document that has been replaced, usually twice.

The query behind this page is literal: the single term for steel pipe flange, run against the State Administration for Market Regulation national standards registry on 14 November 2026. It returned 62 rows over two pages with no shortfall and 62 unique codes, so the counts below are complete rather than sampled.

What the query returns

State	Records	Mandatory
Current	10	0
Abolished	52	0
Total	62	0

Every one of the 62 is a recommended standard. There is no mandatory (GB) flange record in this result set, which matters for compliance language: a flange drawing is a contract document and an engineering choice, not a certification requirement in the way that, say, a pressure-vessel code would be.

The 2010 series is dead — all of it

The clearest finding is structural. The product-type flange standards issued in 2010 are recorded as abolished, one by one:

Abolished record	Scope in translation
`GB/T 9113-2010`	Integral steel pipe flanges
`GB/T 9115-2010`	Welded-neck steel pipe flanges
`GB/T 9116-2010`	Hubbed slip-on steel pipe flanges
`GB/T 9117-2010`	Hubbed socket-weld steel pipe flanges
`GB/T 9118-2010`	Loose hubbed flanges with welded-neck collar
`GB/T 9119-2010`	Plate slip-on steel pipe flanges
`GB/T 9120-2010`	Loose plate flanges with welded-neck collar
`GB/T 9121-2010`	Loose plate flanges with welded slip-on collar
`GB/T 9122-2010`	Lapped pipe-end steel pipe flanges
`GB/T 9123-2010`	Steel pipe blank flanges
`GB/T 9114-2010`	Hubbed threaded steel pipe flanges
`GB/T 9124-2010`	Steel pipe flanges — technical conditions

Behind them sits a deeper layer: the 2000 editions of the same families, split by facing — flat face, raised face, male-and-female, tongue-and-groove, ring joint. Those are abolished as well, and the registry carries them as separate rows: `GB/T 9113.1` to `9113.4`, `9115.1` to `9115.4`, `9116.1` to `9116.4`, `9117.1` to `9117.4`, `9118.1` and `9118.2`, `9119-2000`, `9120.1` to `9120.3`, `9121.1` to `9121.3`, `9123.1` to `9123.4`, plus `9112-2000` and `9112-2010` on types and parameters.

That is why the abolished count is so large: the registry is showing two complete generations of a deliberately sub-divided system, both superseded.

What actually survives: the PN and Class split

The current set is small and coherent. It is organised around two pressure-rating systems rather than around flange shapes:

Current record	Issued	What it covers
`GB/T 9124.1-2019`	10 May 2019	Steel pipe flanges — Part 1: PN series
`GB/T 9124.2-2019`	10 May 2019	Steel pipe flanges — Part 2: Class series
`GB/T 43079.1-2023`	7 Sep 2023	Selection of flanges, gaskets and fasteners — Part 1: PN series
`GB/T 43079.2-2023`	7 Sep 2023	Selection of flanges, gaskets and fasteners — Part 2: Class series
`GB/T 9125.1-2020`	29 Sep 2020	Fasteners for steel pipe flange joints — Part 1: PN series
`GB/T 9125.2-2020`	21 Jul 2020	Fasteners for steel pipe flange joints — Part 2: Class series
`GB/T 9128.1-2023`	7 Sep 2023	Metal ring gaskets for steel pipe flanges — Part 1: PN series
`GB/T 9128.2-2023`	7 Sep 2023	Metal ring gaskets for steel pipe flanges — Part 2: Class series

Two of the ten current records are the large-diameter pair: `GB/T 13402-2019` on large-diameter steel pipe flanges and `GB/T 13403-2023` on gaskets for them, replacing the 2010 and 2008 editions respectively.

The design logic is worth stating plainly, because it changes how a purchase order should be written. PN and Class are not two names for the same scale and they are not interchangeable by conversion alone; the standards body kept them in parallel parts, with parallel selection rules and parallel fastener and gasket parts. A drawing that says "flange to GB/T 9124" without naming PN or Class is incomplete.

Gaskets and bolts moved with the flanges

The joint is a system, and the registry treats it that way. The three current gasket and fastener families each carry a PN part and a Class part issued in the same wave as the flange parts.

The old gasket trail is fully closed: `GB/T 9128-2003` on ring-gasket dimensions, `GB/T 9130-1988` and `GB/T 9130-2007` on ring-gasket technical conditions, and `GB/T 13403-2008` on large-diameter gaskets are all recorded as abolished. Anyone still specifying the 2003 dimension table for a ring joint is working from a withdrawn document.

What the registry does not tell you

No dimensions and no facings. The rows carry code, title, nature, issue date and state. Face type, bolt circle, thickness and bore are in the body of the standard.
No pressure-temperature ratings. The PN and Class series names imply a rating system, not a rating value for a given material at a given temperature.
No supersession field. The registry marks a record abolished but does not always name what replaced it. Where a replacement is visible here, it is because both records appear in the same result set and the titles line up.
No current counterpart for types and parameters. `GB/T 9112-2000` and `GB/T 9112-2010`, which covered flange types and parameters, are both abolished, and this result set contains no current record with that title. Treat the parameter framework as living inside the 9124 series rather than as a separate live document — but confirm that with the standard text, not with this page.
No material standards. Steel grades for flanges sit in separate material standards that this query does not return.

What to put on the drawing and the order

Three fields do most of the work, and all three are visible in the current set:

The series — PN or Class. It selects which part of 9124 applies, and which parts of 43079 and 9125 apply with it.
The joint configuration — flange type plus facing. The current standard organises these inside the series parts rather than as separate product standards, which is exactly what the dead 2010 series used to do.
The gasket and fastener parts — named by their own part numbers, not implied by the flange number.

A supplier quoting from the 2010 series is not necessarily quoting a bad product, but the paperwork will not match a 2019-series drawing, and a third-party inspection will notice.

Flanges rarely sit alone. The pipe fittings page covers the matching butt-weld and threaded fittings, the valve page covers the bodies they bolt to, and the seals page covers the gasket and groove side of the joint. If the question is how GB, GB/T and GB/Z records differ in the first place, the GB standards explainer sets out the classification.

Frequently asked questions

How many GB records cover steel pipe flanges?

The registry returns 62 records for the term steel pipe flange as at 14 November 2026: 10 current and 52 abolished. All 62 are recommended standards; none is mandatory.

Is GB/T 9115-2010 still valid?

No. GB/T 9115-2010, the 2010 welded-neck flange standard, is recorded as abolished. The live family is the 2019 two-part split, GB/T 9124.1-2019 for the PN series and GB/T 9124.2-2019 for the Class series.

What is the difference between the PN and Class series?

They are two pressure-rating systems kept in separate parts: PN in GB/T 9124.1 and Class in GB/T 9124.2, with selection rules in GB/T 43079.1 and 43079.2 and fasteners in GB/T 9125.1 and 9125.2. A drawing has to name the series, not just the flange type.

Do gaskets and bolts have their own current standards?

Yes. Ring-joint gaskets are split into GB/T 9128.1-2023 for PN and 9128.2-2023 for Class, and fasteners into GB/T 9125.1-2020 and 9125.2-2020. The 2003 gasket dimension record and both older ring-gasket specification records are abolished.

Does the registry give flange dimensions or pressure ratings?

No. Each row carries the code, title, standard nature, issue date and state only. Dimensions, facing details and pressure-temperature ratings sit in the body of the standard, which the registry does not reproduce.

Sources

All sources retrieved 14 November 2026. This page is an independent reading of the sources listed; the official pages themselves are the specification.

Fact used on this page	Source
S1 — All 62 records: code, title, standard nature, issue date and state; page 1 of 2, 50 rows	SAMR national standards registry, 14 November 2026 https://std.samr.gov.cn/gb/search/gbQueryPage?searchText=%E9%92%A2%E5%88%B6%E7%AE%A1%E6%B3%95%E5%85%B0&pageNumber=1&pageSize=50
S2 — Records 51 to 62 of the same result set; 62 unique codes against a reported total of 62, no shortfall	SAMR national standards registry, 14 November 2026 https://std.samr.gov.cn/gb/search/gbQueryPage?searchText=%E9%92%A2%E5%88%B6%E7%AE%A1%E6%B3%95%E5%85%B0&pageNumber=2&pageSize=50