Pipe Saddle Branch Tensile Fixture – Polypropylene Pipe

Tensile fixture for polypropylene saddle branch fittings

The UGC-VG-020 is a special fixture for measuring how well a saddle branch stays attached to a polypropylene pipe. Saddle branches are fused or clamped onto the outside of a main pipe to create an outlet, and the joint has to resist being pulled away. This fixture holds the pipe section rigidly while the testing machine pulls on the branch outlet, so the recorded force reflects the pull-out resistance of the joint rather than the pipe deforming. It is intended for plastic piping manufacturers, fitting suppliers and the labs that qualify their products.

How the fixture is built

The main pipe slides over a mandrel that supports it from the inside, so the wall does not collapse or ovalize as load builds. The mandrel is carried between two steel end plates, and tie rods tie the plates into a stiff frame that does not flex during the pull. The branch outlet points along the machine axis, so the joint is loaded in straight tension instead of peel. An adjustable hole pattern lets the operator position the pipe to suit where the branch sits on the specimen. Specimens are mounted by hand.

Made to your pipe dimensions

Saddle branches come in many combinations of main pipe and outlet size, so this fixture is sized to the customer's specimens rather than sold in fixed catalog sizes. To quote, we need:

• The pipe outside diameter

• The branch outlet diameter

• The capacity required, based on the expected pull-out force

• Your testing machine's coupling

Maximum load is set on request to match the joints you test. The fixture is made of steel and connects through a clevis pin coupling, with other pin sizes covered by adapters.

Typical applications

Uses include joint strength checks on polypropylene pipe fittings, routine quality control in plastic piping production, and qualification of new saddle branch designs. The fixture was built for saddle branch tests to GOST R 52779. If you work to a different specification, send the specimen geometry and loading requirement and we will check whether the same layout applies. For other polymer test setups, see our plastics testing page.

Choosing a testing machine

Size the frame by the expected pull-out force and the fixture's length. Smaller fittings may only need a 10 kN benchtop universal testing machine, while large-diameter branches can call for a floor-standing testing machine with more space between the crossheads. Tell us how you plan to connect to the branch outlet and we will advise on the upper side of the load train as part of the design.

Send the pipe and branch diameters with your machine details and we will engineer the fixture around them: request a quote.