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.
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