F 37 (Flange connection)

The Parflange F37 system is a technology from the hydraulic area of Parker Hannifin, which allows a weld- flange connection of hydraulic pipes.


The connection is made using an application specific edging or retaining ring technology.

Flare Technology

F37 after a flange was drawn to a seamless tube, the tube end to be connected is enlarged by a special Orbitalbördel method, which seals the surface of the pipe end by rolling. The tube end is replaced by a funnel- like shape with an angle of 37 °, which explains the name origin.

An insert ( insert) made ​​of steel, or stainless steel is inserted into the expanded tube end then, the geometry of which is due to the funnel-shaped pipe end. This insert has an O- ring on the side of funnel-shaped to sealingly press on the tube wall. Furthermore, the use of the end face is provided with a groove, into which a profiled seal " F37 Seal" from, for example, Polyurethane is inserted. Alternatively, an embodiment of the insert with a flat face or a composite gasket made ​​of steel, or stainless steel with elastomer sealing lip made of NBR or FKM is possible. For a pipe -to- pipe connection is a special form of the insert, which has both sides funnel-shaped contours with O- ring seal.

Thereafter, the flange is positioned on the tube end, in order to mount this hydraulic to a component or another pipe which is also provided with a flange and the appropriate use.

Retaining ring technology

Wherein the retaining ring technology, the pipe end is provided with a radial groove for receiving a stainless steel retaining ring. The support ring consists of two ring halves, which are within a coil spring and serves to fix the flange. To install the retaining ring flange is drawn to the seamless hydraulic tube. The retaining ring is expanded slipped over the pipe end and snaps into the groove you created earlier. A special inner contour of the retaining ring flange bears against the retaining ring.

Sealing the Parflange F37 retaining ring connection is provided by a composite seal, which is the end face placed at the end of the pipe or a pipe sealing member ( seal carrier pipe ). The tube seal carrier has both sides on soft seals ( " F37 Seal" or O-ring) and one-sided a centering, which facilitates the assembly procedure.


Flare Technology

With the flared end of the tube by crimping the flange having a support surface and can take up forces, which leads to a more stable compound.

The insert has a first sealing function. With its O -ring on the funnel-shaped tube side he seals the connection to the pipe itself. The seal at the connection point is made by the frontally located profiled seal " F37 Seal" or Verbinddichtung. Provided that the connection point has an end-face soft gasket, an insert is used with a corresponding flat face. For the connection of two pipe ends on both sides of an insert with a funnel-shaped contour, and O -ring seal can be used.

At the same time insert reinforces the connection. By the heat generated by the insert major face at the junction, the resulting when screwing the flanges over a larger pressure contact surface may be expanded, thereby increasing the strength of the joint.

Retaining ring technology

The special inner contour of the retaining ring bears against the flange mounted on the end of the tube retainer. When tightening the system creates a positive connection, which is sealed off the front by composite gasket or seal carrier pipe.


The Parflange F37 system is used to connect hydraulic tubes without the use of a thermal joining method welding.

Depending on pipe and flange size the system for pressures up to 420 bar is permitted. Application, this system mainly in the shipbuilding, offshore and generally in the heavy machinery industry, eg Cranes and other lifting devices to operate. In addition, with this technology pipes 16-273 mm outer diameter ( 1/2 "to 10" flange ) can be connected.


The system is approved by leading certification bodies. Connections and mounting dimensions are in accordance with ISO 6162-1/SAE J 518 Code 61 (3000 PSI/210 bar) or according to the ISO 6162-2/SAE J518 code 62 (6000 PSI/420 bar) and ISO 6164 ( 400 bar) standardized.

More information

The advantages with respect to the welding are especially savings in time and costs. So, for example, accounts for at a junction with F37, in contrast to welding, the costly examination by x-rays and cleaning with chemical antioxidants, which makes the technology a total of more environmentally friendly and safer.

Compared with no welding stress corrosion cracking is possible, so that a maximum lifetime of the pipeline can be achieved and maintenance costs.