Plate flanges (PL flanges, flat plate flanges) – flat ring flanges with no hub, cut and drilled from certified plate. Sizes 3/8″ – 80″, PN2.5 – PN100, facings FF / RF. The economical choice for low-pressure utility lines.
What Is a Plate Flange?
A plate flange (also called a flat plate flange or “plate blank”) is a simple flat ring – no raised hub, no neck. It slips over the pipe and is fillet-welded inside and out like a slip-on flange, or used as a blank on vessel nozzles. Because it is cut from plate rather than forged, it costs significantly less – the trade-off is lower pressure capability and fatigue strength, which suits it to water, air, HVAC and low-pressure process lines.
Specifications
| Item | Range |
|---|---|
| Size | 3/8″ – 80″ (DN10 – DN2000) |
| Pressure | PN2.5 – PN100 / Class 125 – 150 equivalents |
| Standard | EN 1092-1 type 01, DIN 2576, ASME B16.5 profile (plate), JIS B2220 |
| Materials | Q235B/S235JR carbon steel plate, 304/316 stainless plate |
| Facing | FF, RF |
| Thickness | Per standard tables or customer calculation |
Plate Flange vs Forged Slip-On
Both weld on the same way, but a forged slip-on flange carries a small hub that reinforces the weld and handles higher stress cycles. Use plate flanges for utility water, compressed air, firewater rings, HVAC and structural connections; use forged flanges for process, hydrocarbon, steam and any cyclic service. Many projects use plate flanges on utility headers and forged on process lines – the economical split.
FAQs
Are plate flanges available in stainless? Yes – 304/316 plate flanges for water treatment and food-grade utility lines.
Can you drill to DIN or JIS patterns? Yes – drilling per EN 1092-1, DIN, JIS B2220, ASME or your drawing. Send the pattern for a quote.
More: Flange Types Guide · What Is a Flange? · Schedule Chart · NPS vs DN · All Articles
Match a plate flange to the mating connection
A plate flange quotation needs the drilling, bore and facing requirements as well as nominal size. Send the mating flange drawing when the existing standard or dimensions are uncertain.
| Order detail | What to provide |
|---|---|
| Standard and designation | State the flange standard, type and pressure designation specified for the project. |
| Drilling | Provide bolt-circle diameter, hole count and hole diameter for a drawing-specific component. |
| Bore and facing | Specify the pipe fit, flange bore and required sealing face, with its finish requirements where applicable. |
| Plate and acceptance | Identify the material specification, required thickness, inspection scope and document requirements. |
Before you order
Compare the complete mating connection, including the gasket and bolting specification. Similar nominal sizes do not establish that two flange standards are interchangeable.
Can a photograph identify an existing plate flange?
A photograph is useful context, but include measured dimensions and any visible marking. A dimensioned sketch is needed when the specification cannot be identified from records.
Related products and references
Request a quotation — send your specification, quantity and drawing to info@pipingfitting.com.