SS 304 Orifice FlangeASTM A182 · ASME B16.36 · Manufacturer, stockist & exporter, India
AISI 304 · UNS S30400 · ORF
An SS 304 orifice flange is a pair of weld neck or slip-on flanges with pressure taps that hold an orifice plate, made from SS 304 to ASTM A182 F304. 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 304 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 F304
- Dimensions
- ASME B16.36
- Grade
- SS 304 · UNS S30400
- Best at
- General corrosion resistance, food, water and architectural work
SS 304 Orifice Flange Specification
| Product | SS 304 Orifice Flange |
|---|---|
| Material standard | ASTM A182 F304 |
| 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 304 Orifice Flange: Why 304 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 304, 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 304 is picked for general corrosion resistance, food, water and architectural work. |
|---|---|
| Typical service | Food & dairy — Tanks, piping and equipment that must be cleaned daily. |
| B16.5 material group | 2.1 |
| Bolting | ASTM A193 B8 studs with A194 8 nuts |
| Welding to carbon steel | ER309L (or E309L electrode) is the usual filler when joining it to carbon steel |
| Matching filler | ER308 / ER308L (AWS A5.9) |
SS 304 Orifice Flange Chemical Composition
| Element | Weight % |
|---|---|
| Chromium | 17.5 – 19.5 |
| Nickel | 8.0 – 10.5 |
| Carbon | 0.07 max |
| Manganese | 2.00 max |
| Silicon | 0.75 max |
| Nitrogen | 0.10 max |
| Phosphorus | 0.045 max |
| Sulphur | 0.030 max |
SS 304 Orifice Flange Mechanical Properties
| Annealed plate & sheet | Value |
|---|---|
| Tensile strength | 515 MPa · 75 ksi |
| Yield strength 0.2% | 205 MPa · 30 ksi |
| Elongation | 40% |
| Hardness | 201 HB max |
Full chemistry, properties and equivalents are on the SS 304 grade page.
Other SS 304 flanges
SS 304 Orifice Flanges for export
FOB / CIF · Nhava Sheva (JNPT), MumbaiSS 304 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.
What pressure rating does a SS 304 orifice flange have?
It depends on class and temperature. SS 304 forgings are in ASME B16.5 material group 2.1; read your class column in that group's table at the design temperature.
Can SS 304 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 304 orifice flanges?
The material is ASTM A182 F304; 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 304 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