Lap Joint Flange Pn16, DN125, RF, Q235B Hg20592-2009

• Customization: Available
• Standard: ANSI, DIN, GB, JIS, GOST, BSW
• Type: Welding Flange
• Model NO.: DN200
• Material: Stainless Steel
• Structure: Round
• Connection: Welding
• Sealing Surface: RF
• Manufacturing Way: Forging
• Other Type of Sealing Face: Rtj FF
• Transport Package: Standard Export Plywood Case
• Specification: 1/2" to 24"
• Trademark: XINQI
• Origin: China
• HS Code: 7307210000
• Production Capacity: 300 Pieces/Day
• Package Size: 100.00cm * 100.00cm * 110.00cm
• Package Gross Weight: 1800.000kg

Product Description

Lap joint flange

A lap joint flange, also known as a loose flange, is a type of detachable piping component designed for flexible connection in industrial pipeline systems. It consists of a circular flange ring with bolt holes and a matching stub end (or lap joint stub) that is welded to the pipe. The flange ring loosely fits over the stub end's shoulder, allowing rotational adjustment during installation—eliminating alignment challenges common with fixed flanges. This design combines reliable sealing performance with cost-effectiveness and ease of maintenance, making it widely used in various industrial sectors.
 Core Structural & Performance Advantages
 Flexible Installation: The loose flange ring can rotate 360° around the stub end, enabling quick alignment of bolt holes even in misaligned piping, significantly reducing installation time and labor costs.
Cost Optimization: The stub end (welded to the pipe) is manufactured from material compatible with the conveyed medium (e.g., corrosion-resistant alloys for harsh media), while the flange ring can use lower-cost materials (e.g., carbon steel) for non-corrosive or low-stress conditions—reducing overall material expenses without compromising system integrity.
Easy Maintenance & Replacement: When repairs or replacements are required, only the flange ring needs to be removed (no pipe cutting or welding), minimizing downtime and operational disruption.
Reliable Sealing: Available with multiple sealing face types (e.g., Raised Face/RF, Flat Face/FF, Ring Type Joint/RTJ) to match different gasket materials (PTFE, EPDM, spiral wound gaskets), ensuring leak-proof performance under specified pressure and temperature ranges.
Wide Pressure & Temperature Adaptability: Engineered to handle nominal pressures from Class 150 to Class 2500 (PN1.0 to PN42.0 MPa) and temperature ranges from -200℃ to +600℃, depending on material selection and standard compliance.

Specification

DN15 DN20 DN25 DN32 DN40 DN50 DN65 flange	1/2" 3/4" 1" 1-1/4" flange	WN   SOH  SOP   Threaded  BL   Lap Joint Socket Welding  weld on flanges
DN80 DN100 DN125 DN150 DN200 flange	1-1/2"  2"  2-1/2"  3"  4" 5" 6" 8" flange	WN   SOH  SOP    BL  Lap Joint weld on flanges
DN250 DN300 DN350 DN400 DN450 flange	10"  12"  14"  16"  18"   flange	WN   SOH  SOP    BL   Lap Joint   weld on flanges
DN500 DN600 DN700 DN750 DN800 flange	20"  22"   24"  28"  30"  32"  flange	WN   SOH  SOP     BL   Lap Joint weld on flanges
DN800 DN900 DN1000 DN1200 flange	36"  40"  flange	WN  SOH  BL

Company Profile

Hebei Xinqi Pipeline Equipment Co., Ltd

Since: 2017
Specialty: high quality steel flanges  in pipeline connextion solutions
Capacity:   5 tons/week
Advanced Features:

High-Temperature & Mechanical Performance
Excellent Weldability by all standard methods
Good machinability and formability for producing various flange types and sealing faces.

Advantages

Factory Capabilities

with minimal risk of intergranular corrosion post-welding, simplifying fabrication and field installation

The non-porous, smooth surface is easy to clean and sterilize, preventing contamination.

Advanced Production Lines:

Cutting:  industrial machines with laser guidance

Meets stringent hygienic standards for food, beverage, pharmaceutical, and biotech applications.
Quality Control:

records of all examinations are ready for check.

Sealing

Common Types

Compatible with various gaskets (spiral wound, RTJ, PTDE) to achieve leak-proof connections under pressure.

Weld Neck (WN) flanges are most common for critical services due to their strength. Slip-On (SO), Blind (BL), and Threaded types are also widely used.

Certifications

ISO 9001

SGS verify

Export Certificate

2015 Certified Production

SGS Certified

FAQ

Primary Application Areas:

Chemical & Petrochemical Processing
· Offshore & Marine Systems (seawater handling)
· Oil & Gas Production (especially with high chloride content)
· Pharmaceutical, Food & Dairy Processing
· Power Generation (FGD systems, nuclear auxiliary piping)
· Pulp & Paper Industry