Flange Types: Weld Neck, Slip-On, Blind, Socket Weld, Threaded & Lap Joint

Flange Types: Weld Neck, Slip-On, Blind, Socket Weld, Threaded & Lap Joint

Complete guide to the flange types we manufacture – weld neck, slip-on, blind, socket weld, threaded, lap joint and flat face flanges in carbon steel, stainless steel and alloy steel, from 3/8″ to 160″ and PN2.5 to PN400 / Class 150 to 2500.

What Is a Flange?

A flange is a forged ring that connects pipes, valves, pumps and vessels, bolted with a gasket between the sealing faces. Flanges allow easy assembly, disassembly, inspection and cleaning of piping systems. For a full explanation see What Is a Flange?

Types of Flanges

Weld Neck Flange

Weld Neck Flange

Weld neck flanges (WN) have a long tapered hub for superior stress distribution, ideal for high-pressure and high-temperature piping. Pressure classes 150-2500. View Weld Neck flange details →

Slip-On Flange

Slip-On Flange

Slip-on flanges (SO) slide over the pipe and are welded inside and outside. Economical and easy to align, for low-pressure service PN6-PN100. View Slip-On flange details →

Blind Flange

Blind Flange

Blind flanges (BL) seal pipe ends or vessel nozzles. Available in FF, RF, MFM, TG and RJ facing, class 150-2500. View Blind flange details →

Socket Weld Flange

Socket Weld Flange

Socket weld flanges (SW) for small-bore high-pressure piping up to 3″. The pipe is inserted and fillet-welded. View Socket Weld flange details →

Threaded Flange

Threaded Flange

Threaded flanges (TH) screw onto the pipe without welding – suited where welding is impractical, 3/8″ to 4″. View Threaded flange details →

Lap Joint Flange

Lap Joint Flange

Lap joint flanges (LJ) pair with a stub end, allowing bolt alignment and easy rotation for maintenance. View Lap Joint flange details →

Flat Face Flange

Flat Face Flange

Flat face (FF) flanges mate with cast iron or ductile iron equipment to prevent bolting stress cracking. View Flat Face flange details →

ISO / DIN EN 1092-1 Flange

ISO / DIN EN 1092-1 Flange

DIN and EN 1092-1 flanges in PN6-PN100 pressure ratings with type 05 blind, type 01 plate and welded-neck forms. View ISO / DIN EN 1092-1 flange details →

Flange Standards We Supply

StandardPressure RatingsSizes
ASME B16.5 / ANSIClass 150 – 25001/2″ – 24″
ASME B16.47Class 75 – 90026″ – 60″
DIN 2576 / 2633 / 2634PN6 – PN100DN10 – DN4000
EN 1092-1PN2.5 – PN400DN10 – DN4000
JIS B22205K – 63K10A – 1500A
GB / HG (China)PN2.5 – PN400DN10 – DN4000

Sealing Faces (Flange Facing)

We machine all standard facing types: FF (flat face), RF (raised face), MFM (male-female), TG (tongue-and-groove) and RJ (ring joint). Pairing the right facing with the right gasket prevents leaks – see our flange gasket guide.

Flange Sizes & Dimensions

Need dimensions? Check our flange size charts for ASME B16.5 Class 150-2500 covering OD, bolt circle, number of bolts and thickness for each class.

Request a Quote

Send your drawing or specification to request a free flange quote – custom sizes, special materials and OEM marking available.