ASTM A335 P11 UnionASTM A182 · MSS SP-83 · Manufacturer, trader & exporter, India
SA-335 P11 · 1¼Cr-½Mo alloy pipe
An ASTM A335 P11 union is a three-piece forged fitting that joins pipes and can be taken apart, for use with ASTM A335 P11 pipe. ASTM A335 P11 itself is a pipe or plate specification, so the matching union is made to ASTM A182 F11 — which is what we supply for P11 lines. Unions let a small-bore line be disconnected for maintenance without cutting. Made to MSS SP-83 in threaded or socket-weld ends.
- ASTM A182
- MSS SP-83
- EN 10204 3.1 / 3.2
- Export packing
Reviewed by the Kanak Steel & Engineering Co. technical team · Updated October 2026
What is an ASTM A335 P11 Union?
- What it is
- A three-piece forged fitting that joins pipes and can be taken apart
- Material
- ASTM A182 F11
- Dimensions
- MSS SP-83
- Grade
- ASTM A335 P11
- Best at
- Steam and hot-oil piping up to about 550 °C
ASTM A335 P11 Union Specification
| Product | ASTM A335 P11 Union |
|---|---|
| Material standard | ASTM A182 F11 |
| Dimensional standard | MSS SP-83 |
| Sizes | ⅛" – 4" (ASME B16.11) |
| Wall / class | Class 2000 / 3000 / 6000 / 9000 |
| Ends | Socket weld · NPT threaded |
| Testing | Chemical & mechanical per heat · NDT · impact where specified |
| Documents | EN 10204 3.1 or 3.2 on request / as specified in the PO |
When to Choose an Union
Unions let a small-bore line be disconnected for maintenance without cutting. Made to MSS SP-83 in threaded or socket-weld ends.
- Three pieces: nut, male and female ends
- Threaded or socket weld
- Class 3000 / 6000
More on choosing: Union guide.
ASTM A335 P11 Union: Why P11 for unions
Unions let a small-bore line be disconnected for maintenance without cutting. Made to MSS SP-83 in threaded or socket-weld ends. In ASTM A335 P11, the choice usually comes down to the medium and temperature — the rows here are the points buyers check for this exact combination.
| Why this grade | Carbon and low-alloy fittings suit hydrocarbon, steam and utility lines. ASTM A335 P11 is picked for steam and hot-oil piping up to about 550 °C. |
|---|---|
| Typical service | Power plants — Main steam and reheat lines. |
| Welding to carbon steel | Matching carbon or low-alloy filler is used; joints to stainless need ER309L |
| Matching filler | ER80S-B2 / E8018-B2 |
ASTM A335 P11 Union Chemical Composition
Under technical review for TDS.
| Element | Current requirement |
|---|---|
| Chromium | As specified |
| Molybdenum | As specified |
| Carbon | As specified |
| Manganese | As specified |
| Silicon | As specified |
| Phosphorus | As specified |
| Sulphur | As specified |
Numerical specification requirements are published only after the applicable current standard edition has been verified. Governing specification to be verified: ASTM A335 Grade P11.
ASTM A335 P11 Union Mechanical Properties
Under technical review for TDS.
| Property | Current requirement |
|---|---|
| Tensile strength | As specified |
| Yield strength 0.2% | As specified |
| Elongation | As specified |
Numerical specification requirements are published only after the applicable current standard edition has been verified. Governing specification and condition to be verified: ASTM A335 Grade P11 — condition per order.
Full chemistry, properties and equivalents are on the ASTM A335 P11 grade page.
Other ASTM A335 P11 pipe fittings
ASTM A335 P11 Union — questions buyers ask
Can unions be used in high-pressure lines?
Class 3000 and 6000 unions are rated for high pressure on small bores, but many codes limit their use in hazardous service.
Can ASTM A335 P11 unions be welded to carbon steel?
Yes — matching carbon or low-alloy filler is used; joints to stainless need ER309L.
Which standard covers ASTM A335 P11 unions?
The material is ASTM A182 F11; dimensions follow MSS SP-83. Always state both on your purchase order, with the edition if your project specifies one.
What decides the price of a ASTM A335 P11 union?
The steel price, the size and schedule or class, quantity, and the testing and documents required. Send your list and we quote the same working day.
What documents do you supply?
EN 10204 3.1 or 3.2 certificates available on request / as specified in the PO; dimensional reports as required. PMI can be arranged depending on product and requirements, as specified in the PO.
Sources: the ASTM / ASME specifications named on this page and producer datasheets · Last updated October 2026