The API 623 globe valve is the American Petroleum Institute standard for steel globe valves in petroleum and natural gas service, covering NPS 1/2 through NPS 24 across ASME Class 150 to Class 2500. It differs from BS 1873 in three practical ways: heavier wall thickness, larger minimum stem diameters, and mandatory low-emission packing that BS 1873 does not explicitly require.
The DIN 3352 standard serves European-engineered projects using the PN pressure rating system and is not directly interchangeable with either API or BS valve specifications. Choosing between the three comes down to project code, geography, and client preference rather than technical performance differences.
What Is the API 623 Standard?
API 623 is the American Petroleum Institute standard for steel globe valves in petroleum and natural gas service. Sizes from NPS 1/2 through NPS 24, pressure classes from ASME Class 150 through Class 2500.
Wall thickness requirements under API 623 run more conservatively than most equivalent standards. That adds weight and cost. It also adds a safety margin that matters in high-pressure, high-temperature refinery service, where a valve failure is not just a maintenance event.
Stem diameter minimums under the API 623 standard are larger than BS 1873 or DIN equivalents. Bigger stems mean lower risk of failure under high operating torque in heavy-duty throttling service. Not an academic distinction. It shows up in high-pressure globe valve failures on projects that switched to lighter-spec valves to save money.
Low-emission packing is another defining feature. The API 623 globe valve requires packing arrangements meeting fugitive emission limits consistent with EPA Method 21. That requirement is not present in BS 1873 or DIN 3352 in the same explicit form. For operators running under environmental compliance programs, that matters.
Disc guidance is also specified. Guided disc design reduces flutter under flow conditions, which improves shutoff reliability and seat life in throttling service. Worth noting if the application involves frequent throttling rather than simple on-off isolation.
API Globe Valve
Engineered for high-performance flow control, this API globe valve delivers reliable sealing in high-pressure and high-temperature environments. Ideal for water, oil, and steam systems.
- Valve Size: 1/2″ – 24″
- Pressure Class: 150Lb – 600Lb
- Body Material: WCB, CF8, CF8M, WC6, WC9
- Temperature Range: -29°C to 425°C
- Sealing Options: STL, Hastelloy, Titanium Alloy
- Applicable Media: Water, Oil, Steam
API 623 vs BS 1873: Key Differences
BS 1873 is the British Standard for steel globe valves. Predates API 623. Similar pressure classes and size ranges, but different design requirements in the details that matter.
| Feature | API 623 | BS 1873 |
| Issuing body | American Petroleum Institute | British Standards Institution |
| Size range | NPS 1/2 to NPS 24 | DN15 to DN600 |
| Pressure classes | ASME Class 150 to 2500 | PN16 to PN400 |
| Wall thickness | More conservative | Lighter for the equivalent class |
| Stem diameter | Larger minimum | Smaller minimum |
| Disc guidance | Required | Not always required |
| Low-emission packing | Required | Not explicitly required |
| Typical project use | US, Middle East, Asian refineries | UK, Commonwealth, legacy projects |
API 623 vs BS 1873 in practice comes down to project code and client preference. US clients and major international oil companies using American project standards default to api globe valve critical service specifications. UK clients and projects following British engineering codes specify BS 1873. Both cover similar ranges, but the design philosophy differs where it counts.
One detail worth checking in API 623 vs BS 1873 is flow passage sizing. BS 1873 allows slightly more flexibility in internal runner diameter, which affects Cv values for identical nominal sizes. For throttling applications, check the actual Cv rather than assuming equivalence between the two standards.
Where DIN 3352 Standard Fits
DIN 3352 covers globe valves manufactured to German and European norms. Uses the PN pressure rating system rather than ASME Class, which means a direct comparison requires conversion before specifying.
DIN and EN globe valves dominate European-based projects. Germany, Scandinavia, Central Europe. Projects funded and engineered there specify DIN 3352 standard globe valves because the local supply chain, documentation norms, and inspection processes are built around DIN and EN standards. Specifying API 623 in a DIN project creates flange drilling incompatibilities and documentation mismatches that cause delays nobody wants.
The DIN 3352 standard vs API 623 choice is less about which performs better technically and more about which ecosystem the project lives in. Match the valve standard to the project standard. Mixing them creates problems that are entirely avoidable.
Practical Selection Tips for Globe Valve Standard Specification
Specify an API 623 when the project follows US engineering codes, when the client is a major international oil company with API-based specifications, when low-emission packing compliance is a project requirement, or when the project sits in the Middle East, where API standards dominate EPC specifications.
BS 1873 works when the project follows British engineering codes and when the client explicitly accepts it as an alternative to API 623. Some clients list BS 1873 as an approved alternative in their vendor qualification documents. Confirm that before specifying rather than assuming.
DIN 3352 standard globe valves belong in European-engineered projects using the PN pressure rating system. When the rest of the piping system uses DIN flanges and fittings, mixing in API-flanged valves creates field installation problems that show up at the worst possible time.
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Frequently Asked Questions
What is the difference between API 623 and BS 1873?
API 623 requires heavier wall thickness, larger stem diameters, guided disc design, and low-emission packing. BS 1873 is less prescriptive on those points. Both cover similar pressure classes and sizes, but serve different project code ecosystems.
What are the three types of globe valves?
Z-body, Y-body, and angle body. Z-body is the standard configuration. Y-body reduces pressure drop. Angle body suits piping layouts needing a 90-degree flow change at the valve location.
What is the API 623 standard?
The American Petroleum Institute standard for steel globe valves in petroleum and gas service. Covers NPS 1/2 through NPS 24 in ASME Class 150 to 2500, with specific requirements for wall thickness, stem diameter, disc guidance, and low-emission packing.
What is the API standard for a globe valve?
API 623 is the primary standard for steel globe valves in refinery and petrochemical service. API 602 covers compact valves in smaller sizes. API 623 is the standard most referenced in major EPC project specifications globally.
