Equal Tees Adapter AC/AD — Metric Male 24° Cone Run Tee, L and S Series

Why This Equal Tees Adapter Passes the Compliance Gate

On a tee, the branch sees the same pressure as the run and twice the bending moment, so a tee is the weakest point in most tube circuits. Every AC/AD equal tees adapter is bored from a forged body — never from a welded assembly — with the branch axis square to the run axis within the drawing tolerance, the three 24° cone seats machined in one fixturing setup so that the seats are concentric with their own threads, and the branch wall thickness verified by sectioning on the first article of each lot. Threads are gauged 6g go / no-go and the cone seals are profile-checked.

The fitting is a run tee with three metric male 24° cone ends (DIN 2353 / ISO 8434-1) of the same size — an equal tee, not a reducing tee — with the branch at 90° to the run. “AC” is the range that covers the extra-light (LL) and light (L) series; “AD” is the heavy (S) series.

Core Advantages

• Forged one-piece body. No weld in the pressure path, so no weld porosity, no heat-affected zone and no radiographic inspection requirement.
• Equal bore. All three connections are the same size, so the tee adds almost nothing to the system pressure drop compared with a reducing tee or a pair of adapters.
• Extra-light to heavy class in one family. AC covers tubes 4 to 42 mm at 10 MPa (LL), 25 MPa and 16 MPa (L); AD covers tubes 6 to 38 mm at 63 MPa, 40 MPa and 31.5 MPa (S).
• Three cone seats, one standard. All joints are metric 24° cone, so the tee uses the same tube ends and the same tools as the rest of the circuit.
• Clear identification. Part number, size and material are marked on the body so a service technician can identify a failed tee without a drawing.

Technical Specifications

What Is an Equal Tees Adapter?

It is a three-way hydraulic fitting with one straight run and one perpendicular branch, all three ends being metric male studs with external 24° cones. “Equal” means the three connections are the same nominal size. It splits one flow into two, or combines two flows into one, at a right angle.

The Three Connections — Metric Male 24° Cone

Each end is a metric male stud with an external 24° cone per DIN 2353 / ISO 8434-1 and a 6g metric thread. In the AC range the thread follows the extra-light (LL) or light (L) series; in the AD range it follows the heavy (S) series, one thread size larger for the same tube OD with a heavier wall. Threads run from M8×1 in the LL sizes to M52×2 at the top of the L and S ladders.

This is a 24° cone system and does not interchange with a 60° cone (BSP, DIN 3861 / ISO 1179) or a 37° flare (JIC, ISO 8434-2). The included angles and contact diameters differ, and a mixed joint may pass a static test and leak once the line reaches working temperature.

Equal Tee or Branch Tee with Swivel Nut?

Both fit the same job — three-way flow at 90° — but they assemble differently:

If the branch tube cannot be rotated to match a fixed stud, choose the branch tee with swivel nut; if the branch is a port in a manifold block, the equal tee is the simpler and cheaper part.

Dimensional Data

In the drawing, E is the thread designation of the connections, D1, D2, D3 the tube outside diameters of the three ports, l1, l2, l3 the stud reaches from each end face to the axis, L1, L2, L3 the overall length of each leg measured along its own axis, S1 the body hex and S2, S3, S4 the end hexes.

The run is dimensioned along one axis (L1 and L3) and the branch along the perpendicular axis (L2). On a tee these two directions are not exchangeable: rotating the body to change the branch direction also changes which leg faces the wrench. Check the branch direction and the two run-leg dimensions, in both the length and the height direction, against your installation drawing.

Full Dimension Table (Part Number Matrix)

Values as published in the HENGHUA catalogue drawing. Dimensions in millimetres.

Thread Size and Dash Chart

Note that two different tube sizes can share one thread in the extra-light range — AC-10A and AC-12A are examples — so the part number, not the thread, identifies the tube size you will actually receive.

Matériaux et traitements thermiques

Carbon steel bodies, forged, hardened according to pressure class and plated with trivalent chromium or zinc-nickel. Stainless 304 / 316L available to order. The three cone seats are produced in one operation so that the branch cone is concentric with the branch thread.

Working Pressure and Operating Envelope

The pressure column is the working pressure of the connection, not a burst pressure; a 4:1 burst ratio is typical of the body. A tee is a stress concentration: the branch junction of a large-bore tee is the place to check when a circuit is run at its limit. Size the branch for the flow it actually carries — a tee splitting 60/40 has to be sized on the branch side, not the run side.

Temperature Range

−40 °C to +120 °C for standard components; to +200 °C with FKM in associated seals. The steel joint itself is not the limiting factor; the tube end and the system fluid usually are.

How to Read the Part Number Matrix

AC-14 reads: family AC (equal tee, extra-light or light series), size 14 = 8 mm tube / M14×1.5 on all three ends. AD-20 is the heavy equivalent: size 20 = 12 mm tube / M20×1.5. The numbers follow the series ladder, not the millimetre tube OD, so always quote the tube size and the thread together when cross-referencing.

Selection and Ordering

Selection Checklist / Decision Table

Cross Reference Service

Send the OEM number, the tube OD and the thread, or a photograph of the tee. We return a mapped part number with the three leg dimensions filled in and confirm which end is the branch.

Emballage et logistique

Threads protected on all three ends, plastic bag, carton, pallet; certificates and inspection reports referenced to the heat number. Air, sea and express shipping available.

Installation and Fitment Guide

Step-by-Step Assembly

1. Verify all three ports are metric 24° cone (DIN 2353 / ISO 8434-1) and that the thread size matches the ordered series.
2. Clean the three cone seats and the mating ports. Remove swarf, paint and old sealant.
3. Lubricate the threads lightly; never apply sealant to a 24° cone.
4. Decide the branch direction first. On an equal tee the body position is set by the torque position of the studs, so the branch must end up where the tube run needs it.
5. Start all three threads by hand before tightening any of them; then torque the two run ends first, holding the body by the S1 hex.
6. Torque the branch end last, using the end hex (S2/S3/S4) and a wrench on the body so the finished joints are not disturbed.
7. Re-check all three joints after the first thermal cycle.

Torque and Sealing Notes

Each of the three joints has its own torque value and each is a metal-to-metal 24° cone. Under-torque leaves the cone short of full contact; over-torque deforms the cone and the port. On a tee, the sequence matters as much as the value: tightening the branch first and then fighting the run ends can leave a joint that was correct when it was made and loose when the assembly is finished. Use a torque wrench, not feel.

Installation Warnings

• Do not mix 24°, 60° and 37° cone components across the three ports.
• Do not use thread sealant anywhere on this fitting.
• Do not use the tee as a structural support; use a clamp or a bulkhead fitting.
• Do not reuse a cone that has been over-torqued, galled or dented.
• Do not assume three wrenches will fit in a confined space — check access before ordering.

Applications and Industries

Equal tees are used to split supply to two actuators, to combine two return lines, in lubrication and pilot circuits, on press and injection-moulding manifolds, on mobile machinery hydraulic blocks, on marine systems and on test benches. The equal tees adapter is the low-pressure-drop answer whenever two equal flows must be taken from one line.

OEM Customization and Quality Traceability

Reducing variants, special leg lengths, special hex, alternative materials and plating are produced to drawing. Incoming material verification, first-article inspection (including sectioning for wall thickness at the branch), thread gauging, cone profile checks, proof pressure testing on sample lots and final inspection are recorded against the order, with EN 10204 3.1 certificates on request.

FAQ

What does “equal” mean? All three connections are the same size. A reducing tee has a smaller branch.

Can I use an equal tee as a manifold? It can split the flow, but it is not a manifold: there is no mounting, no gauge port and no facility to plug an outlet. Use a manifold block where that is needed.

Which end is the branch? The one at 90° to the run. On the drawing it is the leg dimensions along the perpendicular axis (L2 in the catalogue table).

Is the pressure rating the same on all three ends? Yes — the body rating applies to all three connections; the piping attached to each end may have a lower rating.

What is the difference from BC/BD? BC/BD has a swivel nut on the branch so the branch tube can be aligned after the run joints are tight. The AC/AD equal tee has a fixed stud on the branch.

Do I need sealant? No. All three joints are 24° metal cone seats.

Demander un devis

Send the part number, the tube OD, the thread series, the material, the quantity and the working pressure. We will confirm the three end sizes, the branch direction and the wall thickness at the branch, and quote with the inspection documentation included.

Related products in this range: branch tee fittings with swivel nut BC/BD · metric male 74° cone tee adapter AQ · metric male O-ring tee adapter AE · 90° elbow fittings adapter 1C9/1D9 · straight fittings adapter 1C/1D.

Browse the full Hydraulic Adapters range for the complete family, or contact us to request a quote, mill test reports, and samples.