GAZ Poclain 24 Degree Flanges: Identification and Fit
HGW Hydraulics on Feb 3rd 2022
The GAZ Poclain 24 degree flange is a French high-pressure hydraulic flange style associated with Poclain equipment and hydrostatic transmission systems. It is less common than SAE or DIN flanges in many shops, but it matters when servicing imported or specialty equipment.
The connection should be identified carefully because the flange face and thread details are different from other flange families that may look similar at first glance.
Where the Poclain Flange Is Found
Poclain equipment became known for hydraulic drive technology, and Poclain hydraulic motors are used in many markets. The GAZ Poclain 24 degree flange is typically found around that equipment family and related high-pressure hydraulic connections.
When a machine has Poclain-style hydraulics, replacing the fitting by visual comparison to SAE or DIN hardware can create a mismatch.
The 24 Degree Seat
The defining feature is the 24 degree seat. The male flange seals with a female flange or port that has the matching 24 degree geometry.
The Poclain flange also has a lip that protrudes from the flange face. That face detail separates it from SAE, Caterpillar, and Komatsu flange styles.
Thread Details
French GAZ fittings use metric threads that may resemble German DIN connections, but many sizes are not the same. Poclain flanges use fine threads across their sizes.
A fitting that threads partway by hand is not necessarily correct. Thread pitch, seat angle, flange face, lip design, and port geometry all need to match.
Why It Should Not Be Substituted
SAE, Caterpillar, Komatsu, DIN, and Poclain flanges can all appear in global hydraulic fleets. They may be close in size or function, but the sealing surfaces and dimensions are not interchangeable by appearance.
Substituting the wrong flange can damage the mating port, prevent the seal from seating, or create a leak under pressure.
Replacement Checks
Before ordering a replacement, record the equipment make, flange face detail, 24 degree seat, thread pitch, port style, O-ring or seal arrangement, and pressure requirement.
GAZ Poclain flanges are best treated as their own connection family, not as a generic metric or SAE flange.