SS 904L Orifice FlangeASTM A182 · ASME B16.36 · Manufacturer, stockist & exporter, India
Alloy 904L · UNS N08904 · ORF
An SS 904L orifice flange is a pair of weld neck or slip-on flanges with pressure taps that hold an orifice plate, made from SS 904L to ASTM A182 F904L. Orifice flanges are used for flow measurement. Each flange has two ½" NPT pressure-tap holes, and jack screws help separate the pair to change the plate.
- ASTM A182
- ASME B16.36
- EN 10204 3.1 / 3.2
- Export packing
Reviewed by the Kanak Steel & Engineering Co. technical team · Updated October 2026
What is an SS 904L Orifice Flange?
- What it is
- A pair of weld neck or slip-on flanges with pressure taps that hold an orifice plate
- Material
- ASTM A182 F904L
- Dimensions
- ASME B16.36
- Grade
- SS 904L · UNS N08904
- Best at
- Dilute sulphuric acid, phosphoric acid and chloride-bearing cooling water
SS 904L Orifice Flange Specification
| Product | SS 904L Orifice Flange |
|---|---|
| Material standard | ASTM A182 F904L |
| Dimensional standard | ASME B16.36 |
| Sizes | 1" – 24" (ASME B16.36) |
| Pressure class | Class 300 – 2500 |
| Facing | RF · FF · RTJ · tongue & groove |
| Bore | To match pipe schedule (state on order) |
| Testing | PMI · dimensional · NDT and IGC on request |
| Documents | EN 10204 3.1 · 3.2 with third-party inspection |
When to Choose an Orifice Flange
Orifice flanges are used for flow measurement. Each flange has two ½" NPT pressure-tap holes, and jack screws help separate the pair to change the plate.
- Class 300 minimum per ASME B16.36
- Supplied in pairs with jack screws
- Pressure taps: ½" NPT, two per flange
More on choosing: Orifice flange guide.
SS 904L Orifice Flange: Why 904L for orifice flanges
Orifice flanges are used for flow measurement. Each flange has two ½" NPT pressure-tap holes, and jack screws help separate the pair to change the plate. In SS 904L, 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 | Stainless flanges are chosen where carbon steel would rust or contaminate the process. SS 904L is picked for dilute sulphuric acid, phosphoric acid and chloride-bearing cooling water. |
|---|---|
| Typical service | Sulphuric acid plants — Coolers, piping and tanks for dilute sulphuric acid. |
| Bolting | as the project specifies |
| Welding to carbon steel | ER309L (or E309L electrode) is the usual filler when joining it to carbon steel |
| Matching filler | ER385 (AWS A5.9) |
SS 904L Orifice Flange Chemical Composition
| Element | Weight % |
|---|---|
| Nickel | 23.0 – 28.0 |
| Chromium | 19.0 – 23.0 |
| Molybdenum | 4.0 – 5.0 |
| Copper | 1.0 – 2.0 |
| Carbon | 0.020 max |
| Manganese | 2.00 max |
| Silicon | 1.00 max |
| Nitrogen | 0.10 max |
SS 904L Orifice Flange Mechanical Properties
| Annealed plate & sheet | Value |
|---|---|
| Tensile strength | 490 MPa · 71 ksi |
| Yield strength 0.2% | 220 MPa · 31 ksi |
| Elongation | 35% |
| Hardness | 90 HRB max |
Full chemistry, properties and equivalents are on the SS 904L grade page.
Other SS 904L flanges
SS 904L Orifice Flanges for export
FOB / CIF · Nhava Sheva (JNPT), MumbaiSS 904L Orifice Flange — questions buyers ask
Why is the minimum class 300 for orifice flanges?
ASME B16.36 starts at Class 300 so the flange is thick enough to drill the pressure taps radially.
Can SS 904L orifice flanges be welded to carbon steel?
Yes — ER309L (or E309L electrode) is the usual filler when joining it to carbon steel.
Which standard covers SS 904L orifice flanges?
The material is ASTM A182 F904L; dimensions follow ASME B16.36. Always state both on your purchase order, with the edition if your project specifies one.
What decides the price of a SS 904L orifice flange?
The alloy price, the size and pressure 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 mill certificates as standard, 3.2 with third-party inspection on request, plus dimensional and PMI reports.
Sources: the ASTM / ASME specifications named on this page and producer datasheets · Last updated October 2026