Coliter ® Double Flange Limit Expansion Joint – DN65–DN3000, Axial Restriction with Angular Deflection for Pipeline Safety

B2F(VSJJA-2) Double Flange Limit Expansion Joint – Rigid-Limit Type Expansion Joint for Controlled Thermal Movement and Stress Relief in Industrial Piping

The Coliter® B2F(VSJJA-2) Double Flange Limit Expansion Joint is a specialized rigid-limit expansion joint designed to absorb axial thermal expansion and contraction in pipelines while **preventing over-extension** that could damage connected equipment or supports. Installed between two flanged pipe ends, it allows controlled linear movement within a preset range—defined by adjustable limit rods—and simultaneously accommodates minor angular deflection and installation misalignment. Once the pipeline reaches its maximum designed expansion (ΔL), the **limit nuts engage the flange shoulders**, mechanically locking the joint and transferring thrust forces safely to the anchoring system—thereby protecting pumps, valves, and pipe supports from excessive stress. Constructed with a carbon steel or ductile iron body, reinforced sealing rings (NBR, NR, or FPM), and galvanized or stainless steel bolts/nuts, the B2F ensures reliable, leak-free operation under demanding conditions. Available in sizes from DN65 to DN3000, rated for pressures up to 1.6 MPa, and compliant with GB/T 12465 and international standards. Widely used in water supply networks, HVAC systems, power plants, petrochemical facilities, and fire protection pipelines, this joint enhances system safety, simplifies installation, and extends service life by balancing flexibility with structural integrity.