How to Order Pipe Flanges from China | High-Quality Industrial Flanges & Forgings

When sourcing Pipe Flanges from China, providing clear and accurate specifications is essential to ensure correct selection, performance, and long-term reliability. As an experienced manufacturer and exporter, Jizhong helps global customers select the right pipe flanges and components for their projects.

Below are the key details you should specify when placing an order.

1. Nominal Pipe Size (NPS)

The Nominal Pipe Size (NPS) defines the flange size based on the connecting pipe.
Please note that NPS does not always match the flange inside diameter (I.D.).

ASME B16.5: Covers flanges from ½″ to 24″ NPS
ASME B16.47: Covers flanges from 26″ to 60″ NPS

Jizhong supplies pipe flanges ranging from ½″ up to large-diameter custom sizes, suitable for industrial and infrastructure projects worldwide.

2. Pressure Class

The pressure class defines the pressure–temperature rating of the flange and is required for all applications.

Common ASME pressure classes include:
150#, 300#, 600#, 900#, 1500#, and 2500#

Higher pressure classes generally mean:

Larger outside diameters
Thicker flanges
Larger bolt holes

3. Flange Type

The flange type depends on the application and installation method. Common types include:

Weld Neck (WN)
Slip On (SO)
Threaded (THD)
Socket Weld (SW)
Lap Joint (LJ)

Additional types available from Jizhong:

Reducing Flanges (RED)
Long Weld Neck (LWN)
Stub Ends (SE)

4. Facing Type

The flange facing is the contact surface where the gasket is seated.
Facing types and surface finishes (RMS) are defined by ASME B16.5 and B16.47.

Common options include:

Raised Face (RF)
Ring Type Joint (RTJ)
Flat Face (FF)
Large Male (LM) / Large Female (LF)
Large Tongue (LT) / Large Groove (LG)

5. Pipe Schedule

Pipe schedule applies mainly to non-standard flanges, such as:

Socket weld flanges
Stub ends
Orifice flanges
Weld neck flanges (where bore must match pipe wall thickness)

Common schedules range from SCH 5S to XXS.

6. Standards & Specifications

A “standard” refers to specifications established by recognized organizations such as:

Examples include:

ASTM A182 / ASME SA182
ASTM B564 / ASME SB564

These standards define material grades, mechanical properties, and testing requirements.

7. Material Selection

Materials may be identified by trade names or UNS numbers, with UNS being the most widely accepted method.

Common Materials Supplied by Jizhong

Carbon Steel

A105, A36, A516 Gr.70, A572 Gr.50

Stainless Steel

300 Series: 303, 304, 304L, 316, 316L
400 Series: 420J2, 430, 434, 442

Special Alloys

Duplex 2205
Super Duplex 2507
Inconel, Incoloy, Hastelloy
Chrome steel and equivalent alloys

Other materials such as aluminum, titanium, plastics, and rubber-lined solutions can be supplied upon request.

How to Select the Right Pipe Flange

Choose the Correct Connection Type

Different flange connection types are designed for specific applications and are not always interchangeable.
Common connection types include:

Slip-On
Blind
Weld Neck
Threaded
Lap Joint
Socket Weld

Measure the Flange Dimensions Accurately

To determine the correct size, measure:

Outside Diameter (O.D.)
Inside Diameter (I.D.)
Number of bolt holes
Bolt circle diameter (center-to-center)

For reducing flanges, measurements for both pipe sizes are required.

Confirm the Required Pressure Rating

Flange selection is not based on size alone. The pressure class is critical for safety and performance.
Using a higher pressure-rated flange is acceptable (if dimensions match), but never a lower-rated one.

Additional Considerations When Ordering Pipe Flanges from China

Material compatibility with the pipe and application
Required standards (ASME, ANSI, DIN, AWWA, etc.)
Country of origin requirements, especially for infrastructure projects
Accessories needed, such as gaskets, spacers, or stub ends
Lead time and delivery schedule

If standard options do not meet your requirements, Jizhong’s custom manufacturing capabilities allow us to produce or modify flanges according to project specifications.

Partner with Jizhong for Reliable Pipe Flanges from China

With strict quality control, international certifications, and stable lead times, Jizhong is a trusted supplier of Pipe Flanges from China for global B2B customers.