Double Flange Limited Expansion Joint

The Double Flange Limited Expansion Joint (also known as loose expansion joint) consists of body, sealing ring, gland, telescopic pipe, and limit nuts. Dafugui has years of experience in pipeline equipment manufacturing and strictly follows GB/T 12465 standards, with multiple quality inspections from raw materials to finished products. Sizes range from DN50 to DN3000mm, pressures 0.6--2.5MPa, materials include carbon steel, ductile iron, or stainless steel.

Limit Protection for Safety

Double nuts lock at the maximum expansion point. The joint slides freely during normal movement, but once displacement exceeds the limit, rigid limitation engages to prevent pull-out or damage, protecting the entire pipeline system.

Reliable Sealing, Leak-proof

NBR wedge-type sealing ring maintains excellent sealing even during telescopic movement. Pressure-tested with zero leakage within rated range, suitable for water, oil, gas, steam, and other media.

Easy Installation and Applications

Double flange design connects directly to pipeline flanges without special tools. Simply tighten gland bolts diagonally and adjust limit nuts. For overhead installation, only fixed supports at both ends are needed.

Also this product will be suitable for municipal water supply & drainage, wastewater treatment, petrochemical, power, metallurgy, and marine piping systems. Conveys seawater, fresh water, sewage, crude oil, fuel oil, air, gas, and steam up to 250℃.

FAQ

Q1: What is the difference between a Double Flange Limited Expansion Joint and a standard loose expansion joint?

A: A standard loose expansion joint only provides expansion without limit protection, which may cause excessive displacement and leakage. This product adds double-nut limitation that automatically locks when over-displaced, offering greater safety.

Q2: How do I determine the required expansion capacity?

A: Calculate based on pipe length, temperature difference, and coefficient of linear expansion. It is recommended to add a 20%--30% margin to the theoretical value. Contact Dafugui's technical team for assistance in sizing.

Q3: How often should the sealing ring be replaced?

A: Typically 3--5 years, depending on medium corrosiveness and temperature. Replace when cracks, hardening, or continuous minor leakage occur. Dafugui provides genuine replacement parts.

Q4: Can non-standard sizes or special materials be customized?

A: Yes. We support non-standard diameters, stainless steel 316L, FKM sealing rings, and other customizations. Provide your operating parameters and we will work out a solution.

Why Choose Dafugui

• Years of experience in pipeline equipment with strict QC
• Products meet national standards; test reports available
• Customization supported with stable lead times
• Installation guidance and after-sales warranty provided