BlueSky Bluelock Clamp Connector

A robust and compact 4-bolt fitting, the BlueSky BlueLock clamp connector is engineered as a high-performance alternative to flanges.

The BlueSky BlueLock clamp connector is a reliable, easy-to-assemble, metal-to-metal sealed connector designed for use in piping systems requiring high integrity seals in applications involving corrosive, erosive, high temperature, high pressure, and cyclic conditions. It is engineered for pressure vessel nozzles and closures, process piping, compressors, pumps, manifolds, and valves.

Product Description

The clamp joint has the following configuration: 

2 clamps, 2 hubs, 1 seal ring, 4 studs and 8 nuts.

The seal ring is a zero leakage, reusable, metal-to-metal gasket interfaced with the hub sealing surface to ensure high integrity and a reliable seal. The joint configuration ensures that the seal ring is elastically loaded during assembly to offer a self-energized seal during operation.

Freudenberg Flow Technologies will custom design and optimize specialty BlueLock products to suit any application.



Simple 4 Bolt Connection

Just 4 bolts to install, compared with 8-24 bolts for conventional flanges. The BlueLock connector is still effective even when the tightening of bolts is uneven.

Smaller & Lighter

The efficient design results in a BlueLock connector that is substantially smaller in size and much lighter in weight when compared to an equivalent ANSI or API flange class.

Lower bolt torque

Lower torque requirements, no requirement for special hydraulic tensioning.

Decrease Downtime

Quick assembly/disassembly with fewer bolts –and parts- overall, no bolt holes to align.


More Benefits:

  • Economical Solution
    Lower “total installed cost” – particularly in 900# class and higher services.
  • Gas Tight
    The pressure assisted seal tolerates changes in temperature and load for zero fugitive emissions in situations that might cause conventional flanges to leak.
  • Efficient Design, reusable sealrings
    The BlueLock connector sealrings can continue to be used in service, whereas conventional RTJ rings are crushed and not considered reusable.




Pressure Energized, Metal-to-Metal Sealing

The heart of Bluelock's success is the pressure energized seal. BlueSky Bluelock ® clamp connectors do not rely on the conventional flange gaskets and correctly tensioned bolts to maintain the integrity of the seal.

The four basic elements of the BlueSky Bluelock ® clamp connector are hubs, sealring, clamps and bolting. When bolting the assembly, the hubs are drawn together by the twin wedge action of the two clamp segments compressing on the sealring to make the first-stage self-energizing seal.




Technical Specifications


  • The rib of the seal ring is clamped between the hub faces. The rib of the seal ring assists with proper alignment as the connector is clamped together.
  • The seal ring lips engage the inner hub surface. The rib controls the amount of seal ring lip deflection within the elastic range.
  • The seal ring lips deflect inwards to achieve a highly reliable metal-to-metal seal.
  • Internal pressure acts on the inside face of the seal ring lips and pressure energizes the seal to enhance the reliability of the metal-to- metal seal. This feature is significantly superior to traditional flanges in which pressure acts directly on the flange faces, forcing them apart and impacting the integrity of the seal.