Steel Flanges
Steel flanges are ring-shaped carbon steel connection elements that join steel pipe to valves, pumps, heat exchangers and other pipe parts with bolts, in a detachable way.
They are used for flanged equipment connections in building services, fire, steam and process lines. Plate, blind, weld neck, slip-on, threaded and loose types are supplied from DN15 to DN600 in PN6–PN40 and 150 lb classes.
Main Applications
- Flanged valve and pump connections
- Heat exchanger, tank and boiler nozzles
- Fire and sprinkler mains
- Steam and condensate lines
- Closing line ends (blind flange)
- Detachable pipe connections
Technical Data
| Flange types | Plate, blind, weld neck, slip-on, threaded, loose |
|---|---|
| Material | Carbon steel, grade depending on model |
| Size range | DN15 – DN600 (product range) |
| Pressure classes | PN6, PN10, PN16, PN25, PN40 (product range) |
| ANSI class | 150 lb slip-on, DN15 – DN200 (product range) |
| Manufacturer standards | DIN, EN, ANSI, JIS (manufacturer information) |
| Connection | With bolts, nuts and flange gasket |
| Connection to pipe | Welded (plate, slip-on, weld neck) or threaded (threaded flange) |
| Surface | Black or oiled (depending on model) |
| Compatibility | Must have the same DN and PN as the mating flange |
Material Options
| Property | PN6 | PN16 | PN40 |
|---|---|---|---|
| Body | Carbon steel, grade depending on model | Carbon steel, grade depending on model | Carbon steel, grade depending on model |
| Use | Low-pressure water and air lines | General piping, pump and valve connections | Steam and high-pressure lines |
| Bolt hole pattern | PN6 pattern | PN16 pattern | PN40 pattern |
| Mating flange | Same DN and PN | Same DN and PN | Same DN and PN |
| Gasket | Rubber or compressed fibre (depending on model) | Compressed fibre or graphite (depending on model) | Graphite or spiral wound (depending on model) |
Which material? When choosing a flange, DN and PN must be the same as the flange of the valve or pump to be connected; bolt hole patterns may not match across PN classes.
Advantages
Detachable Connection
- Valves and pumps are removed by undoing the bolts
Wide Class Choice
- From PN6 to PN40 and 150 lb
Large Sizes
- Up to DN600
All Types from One Source
- Plate, blind, weld neck, slip-on, threaded, loose
Construction and Design Features
- Ring body with bolt holes according to PN class
- Types joined to the pipe by welding or thread
- Flat or raised gasket face depending on model
- Solid body without bore on blind flanges
Send the flange type, DN and PN class and quantity; we will confirm suitable steel flanges from stock.
How to Choose?
- Determine DN and PNFind the flange size and pressure class of the valve or pump to connect.
- Choose the typePrefer weld neck for high pressure and temperature, plate flanges for general use.
- Plan the pipe connectionUse plate or weld neck on welded lines, threaded flanges on threaded lines.
- Choose the gasketDetermine a flange gasket suited to medium and temperature.
Complementary Products
Why ORFA?
Types of Steel Flanges
Threaded Flanges
Threaded flanges are steel flanges screwed onto the pipe without welding to give a bolted joint.
Details →
Lap Joint Flanges
Lap joint flanges are used with a stub end and make it easy to line up bolt holes during fitting.
Details →
Plate Flanges
Plate flanges are flat steel flanges slipped over the pipe and fixed by welding.
Details →
Weld Neck Flanges
Weld neck flanges have a long neck butt-welded to the pipe and suit higher pressures.
Details →
Blind Flanges
Blind flanges close the end of a pipeline or piece of equipment with a bolted joint.
Details →
Slip-On Flanges
Slip-on flanges are steel flanges slipped over the pipe and welded on the inside and outside.
Details →Other Welded Carbon Steel Fittings
Carbon Steel Eccentric Reducers
Carbon steel eccentric reducers change pipe size on welded lines while keeping one side flat.
Details →
Carbon Steel Butt Weld Caps
Carbon steel butt weld caps are used to close the end of a steel pipe permanently by welding.
Details →
Carbon Steel Butt Weld Tees
Carbon steel butt weld tees split flow in three directions on welded steel pipelines.
Details →
Carbon Steel Concentric Reducers
Carbon steel concentric reducers change pipe size on welded lines along the same centre line.
Details →
Butt Weld Reducing Tees
Butt weld reducing tees are used to take a smaller branch off the main run on welded steel lines.
Details →
Butt Weld Elbows
Butt weld elbows are formed fittings used to change direction on welded steel pipelines.
Details →
Butt Weld Crosses
Butt weld crosses split flow in four directions on welded steel pipelines.
Details →
Single-Side Threaded Nipples
Single-side threaded nipples have one threaded end and one plain end for welding, moving a welded line to a threaded connection.
Details →Get a quote for your project
Our sales team will prepare the best solution for your needs.