A hammer union joins two sections of pipe or hose using a wing nut, so crews can disconnect the line without turning the adjoining pipework. You’ll find hammer unions on drilling mud systems, cementing lines, well service equipment and industrial fluid transfer assemblies. When ordering a replacement, start with the figure and nominal size, then verify the end connection, service and working pressure.
Hammer union figure chart and pressure ratings
Download the A4 Hammer Union Poster (PDF)
This table compares reference pressure ratings for 18 hammer union figures. Each figure links directly to its Safety Shark product page, where you can check size, end connection and service options. A dash means a rating is unavailable in this reference table.
| Figure and product | Standard CWP | Standard test | Sour CWP | Sour test |
|---|---|---|---|---|
| FIG 50 | 500 | 750 | — | — |
| FIG 100 | 1,000 | 1,500 | — | — |
| FIG 101 | 1,000 | 1,500 | — | — |
| FIG 200 | 2,000 | 3,000 | 2,000 | 3,000 |
| FIG 201 | 2,000 | 3,000 | 2,000 | 3,000 |
| FIG 206 | 2,000 | 3,000 | 2,000 | 3,000 |
| FIG 207 | 2,000 | 3,000 | 2,000 | 3,000 |
| FIG 211 | 2,000 | 3,000 | — | — |
| FIG 300 | 3,000 | 4,500 | — | — |
| FIG 400 | 4,000 | 6,000 | 4,000 | 6,000 |
| FIG 602 | 6,000 | 9,000 | 6,000 | 9,000 |
| FIG 1002 | 10,000 | 15,000 | 7,500 | 11,250 |
| FIG 1003 | 10,000 | 15,000 | 7,500 | 11,250 |
| FIG 1004 | 10,000 | 15,000 | 7,500 | 11,250 |
| FIG 1502 | 15,000 | 22,500 | 10,000 | 15,000 |
| FIG 2002 | 20,000 | 30,000 | — | — |
| FIG 2202 | — | — | 15,000 | 22,500 |
| FIG 6666 | 6,000 | 9,000 | — | — |
CWP means cold working pressure. Test pressure is a separate value and must never be used as a working pressure. Use the table to shortlist a figure, then verify the exact assembly’s rating, temperature limits and service from its markings and manufacturer documentation. Ratings can vary with size and configuration.
FIG 602 vs FIG 1002 vs FIG 1502
The reference table lists FIG 602 at 6,000 psi, FIG 1002 at 10,000 psi and FIG 1502 at 15,000 psi cold working pressure for standard service. The reference sour-service ratings for FIG 1002 and FIG 1502 are 7,500 and 10,000 psi respectively. Check the service rating when replacing a union, even if the figure and size match.
Never mix hammer union figures. Some mismatched 2-inch unions can appear to make up because the threads partially engage. IADC documented a fatal incident involving a FIG 602 and FIG 1502 mismatch. Verify that the male sub, female sub and wing nut are manufacturer-approved for use together. Identify them from their markings and documentation. Paint colour and apparent thread engagement are unreliable. Isolate and depressurise the line before working on a connection. See IADC Safety Alert 06–01 and IADC Safety Alert 03–16.
How to specify a threaded or butt-weld hammer union
- Identify the figure and nominal size. Record the markings on the existing parts and check them against the line documentation.
- Specify the pipe end. For a threaded union, confirm the thread standard and size. For a butt-weld union, provide the pipe dimensions and applicable weld-end specification.
- State the service and operating conditions. Provide the fluid, maximum working pressure and temperature range. For sour service involving hydrogen sulphide (H₂S), include the project’s material, seal and documentation requirements.
- Confirm the complete assembly. Check compatibility, traceability and the working limits of the union, adjoining equipment and end connections before putting the line into service.
Hammer union FAQs
Does the figure number tell me the pressure rating?
The figure identifies the union design. The working rating for a particular union comes from its manufacturer documentation and depends on its configuration and service.
Can I identify a hammer union by its paint colour?
Use the stamped identification and manufacturer documentation. Paint can wear off or be reapplied, and colour schemes vary by manufacturer.
What should I send when requesting a quote?
Send the figure, nominal size, end connection, standard or sour service, quantity and working conditions. Clear photos of the markings help when replacing an existing union.
Shop hammer unions in Australia
Browse Safety Shark’s Hammer Unions collection or select your figure from the chart above.