Steel Flanges

Weld-neck, slip-on, blind, threaded, socket-weld and lap-joint flanges from 1/2" to 60", class 150 to 2500. Carbon, low-alloy, stainless and duplex materials for pipelines, pressure vessels and equipment nozzles.

1/2" – 60" (DN15–DN1500)Class 150 – 2500 / PN2.5 – PN100ASME B16.5 / B16.47 / EN 1092-1A105 · A350 LF2 · A182 · A694

Steel Flanges

Flanges are the bolted, removable joint of a piping system — and the component where sealing surface quality decides whether the joint weeps or holds for decades. CREATEEL manufactures and supplies the full range: weld neck, slip-on, blind, socket weld, threaded, lap joint and orifice flanges from 1/2" through 60", in classes 150 to 2500 with RF, FF and RTJ facings.

Every flange is die- or open-die forged, heat treated, fully CNC-machined and facing-serrated in our workshop, with gasket surface finish controlled at 125–250 AARH. Project supply includes hydrostatic records, material certificates and coating per specification.

Every CREATEEL fitting is shipped with full heat-number traceability from raw material certificate to the stamped marking on the piece itself. Dimensional reports, heat treatment charts and EN 10204 3.1 inspection certificates are issued as standard, with 3.2 certification by third-party inspection (SGS, BV, TÜV) available on request before shipment.

Technical Specifications

Applicable Standards

Standard	Scope	Note
ASME B16.5	Flanges NPS 1/2–24″, Class 150–2500	Most common
ASME B16.47	Large-diameter flanges NPS 26–60″	Series A/B
EN 1092-1	Flanges PN 2.5–100	European
API 605 / 6A	Wellhead / high-pressure	Oilfield
MSS SP-44	Steel pipeline flanges	Pipeline
JIS B 2220 / GB/T 9119	Asian national flanges	Japan / China
GOST 33259	Flanges	Russian

Dimensions (ASME B16.5)

NPS	Class	Bore OD (mm)	Bolt circle (mm)	Wall / facing
1/2″	150	21.3	60.3	RF
2″	150	60.3	120.7	RF
4″	150	114.3	190.5	RF
8″	150	219.1	298.5	RF
2″	300	60.3	127.0	RF
8″	300	219.1	319.0	RF

Raised-face (RF), flat-face (FF), ring-type-joint (RTJ) facings available. Full dimension tables per ASME B16.5 / EN 1092-1 on request.

Material Grades

Family	Grade	Spec
Carbon steel	A105 / A105N	ASTM A105
Low-temperature	A350 LF2 / LF3	ASTM A350
Stainless	A182 F304/304L, F316/316L, F321	ASTM A182
Alloy	A182 F11 / F22 / F91	ASTM A182
High-yield	A694 F42–F70	ASTM A694
Duplex	A182 F51 / F53 / F55	ASTM A182

Coating & Surface Treatment

Black / varnished mill finish.
Hot-dip galvanized to ASTM A153 / ISO 1461.
RTJ groove machined to ASME B16.5.
Stainless pickled & passivated.
Anti-rust oil for export.

Packing & Shipping

Plywood cases or pallets, seaworthy packing.
Bolt holes protected, faces covered.
EN 10204 3.1 MTC; 3.2 with SGS / BV / TÜV on request.
MOQ 5 t per item; lead time 15–30 days.

Types & Range

Weld Neck

Tapered hub, full-penetration butt weld — best fatigue and pressure performance.

Slip-On / Socket Weld

Cost-effective for utility and small-bore lines.

Lap Joint + Stub End

Rotating flange for alignment and frequent dismantling.

Blind

Closes ends of lines and nozzles; also used for hydro test isolation.

Materials & Standards

A105 carbon steel covers most ambient service. A350 LF2/LF3 is specified for low temperature; A182 F5/F9/F11/F22/F91 for high-temperature alloy; A182 F304L/F316L for stainless and F51/F53/F55 duplex and super-duplex for offshore chloride service. A694 F42–F70 forged flanges match API 5L line-pipe grades on pipeline tie-ins.

Standards in brief: dimensions per ASME B16.5 / B16.47 / EN 1092-1; bolt threads per ASME B1.20.1 / B1.13; material and heat treatment per ASTM with EN 10204 3.1 / 3.2 certification.

Manufacturing Process

Forging, machining and drilling line for ASME B16.5 / B16.47 steel flanges — from certified bar or forged blank to serrated, marked finished face.

Raw Material

Certified bar, billet or forged blank per A105/A182 with EN 10204 3.1 MTCs and PMI on alloy.

Hot Forging

Blank upset and forged at 1150–1250°C in dies (small sizes) or open die / ring rolled (large), refining grain flow.

Heat Treatment

Normalizing, normalizing+tempering or Q&T per grade and class; test coupons treated with the lot.

Rough & Finish Machining

Face, bore, OD and hub CNC-turned; weld neck taper and bore per schedule.

Drilling

Bolt holes drilled via drilling template/JIG for true bolt circle, spot-faced, holes straddle centerlines.

Facing & Serration

Raised face or RTJ groove machined; serrated spiral 125–250 AARH with finish gauge check.

Testing & NDT

UT per grade spec, MT on critical surfaces, hardness, dimensional report per B16.5 tables.

Marking & Coating

Rim-marked with class, size, material and heat number; black paint, galvanized or machined-bare.

Applications

PRODUCT applications copy

OIL & GAS

Pipeline & Station Flanges

WN and blind flanges carry transmission and gathering lines at Class 150–2500.

✓ ASME B16.5 / B16.47

REFINING

Refinery & Process Plants

Raised-face and RTJ flanges for hydrocarbon and steam services.

✓ A182 F11 / F22

WATER

Water & Desalination

Drinking-water and SWRO trains use corrosion-resistant flanged joints.

✓ EN 1092-1

POWER

Power Plant Piping

High-temperature flanges for boiler and turbine auxiliaries.

✓ A182 F91 / ASME B31.1

OFFSHORE

Marine & Offshore

Sour-service and low-temp flanges for platforms.

✓ A350 LF2 / NACE

CONSTRUCTION

HVAC & Building Services

Slip-on and threaded flanges for plant rooms and skids.

✓ A105 / A105N

Frequently Asked Questions

Which flange types do you supply?

Weld Neck (WN), Slip-On (SO), Blind (BL), Socket Weld (SW), Threaded (TH) and Lap Joint (LJ) — per ASME B16.5 up to NPS 24″ and B16.47 from 26″ to 60″.

Which flange facing should I choose?

Raised Face (RF) is the standard for most services. Ring Type Joint (RTJ) for high pressure and high temperature (Class 900+); Flat Face for mating with cast-iron equipment.

What pressure classes are available?

Class 150, 300, 400, 600, 900, 1500 and 2500 per B16.5; Class 75–900 per B16.47. PN-rated flanges to EN 1092-1 are also available.

What sizes and materials do you cover?

NPS 1/2″–60″. ASTM A105, A350 LF2/LF3, A182 F304/304L/F316/316L, A694 F42–F70 for pipelines, and duplex F51/F53.

How do I match the Weld Neck bore to my pipe?

Specify the pipe schedule with your order — we bore the hub to match the pipe ID so the weld joint sits flush, e.g. 6″ Class 300 WN in Sch 80.

What tests and certificates do you provide?

Tensile, hardness and impact tests per heat (impact for LF2/LF3), PMI for stainless, 100% dimensional check — with an EN 10204 3.1 MTC for every shipment.

How are flanges protected for shipping?

Anti-rust oil or black paint as standard; FBE and hot-dip galvanizing on request. Sealing faces are protected with plastic covers and flanges are bundled or palletized.

What is your MOQ and lead time?

Flexible MOQ. Common sizes in Class 150/300 are often in stock (5–10 days); forged production typically 15–35 days.

Can you supply gaskets and bolting with the flanges?

Yes — spiral-wound or graphite gaskets and ASTM A193 B7/A194 2H stud bolt sets can be packed as matched flange kits.

What marking appears on your flanges?

Per ASME B16.5: manufacturer logo, material grade, size, pressure class, schedule (for WN bore) and heat number — fully traceable to the mill.