Tee port labels: tell a reduced run end from a reduced branch

Three sizes beside a tee do not explain its layout unless you know how that catalogue orders the ports. A tee has two opposed run ends and a branch. If the smaller connection is needed on the branch, an end-reducing tee can be the wrong purchase even when its title contains the same sizes. Describe the required ports before choosing a product name.

Shop the materials with a confirmed port layout

Shop the Compact 22 mm equal tee as an example with three nominally equal connections. For a different arrangement, view the Compact end-reducing tee listing and confirm its labelled port layout before ordering. These are conditional buying examples, not a recommendation that either fits your particular system.

Name the run and branch first

The run is the pair of connections opposite one another across the tee. The branch is the third connection projecting from that run. Those names remain useful when the fitting is rotated in a photograph or installed in another orientation. “Top,” “left” and “bottom” can become confusing as soon as someone turns the picture. Run end A, run end B and branch are clearer labels for a buying sketch.

Write a required nominal pipe size beside each of those three labels. Do not add a flow direction unless it is part of the specification: a buying sketch that identifies ports is not a hydraulic design. Its purpose is to stop a size sequence being read in two different ways by the customer and the merchant.

Read the catalogue’s category as well as its numbers

The Embrass Peerless catalogue separates reducing tees into branch, end, both-ends, and end-and-branch categories. Those headings carry information that a shortened product title can lose. They are reasons to check the exact reference, rather than treating every occurrence of two 22 mm connections and one 15 mm connection as the same tee.

“End and branch” describes a different reduction pattern from “branch” alone. The category explains the intended topology, but a size sequence still needs its manufacturer's ordering convention or a labelled drawing. Do not transfer another brand’s convention to this catalogue or assume that the middle number always represents the branch.

Use an equal tee as a simple reference point

The maker lists Compact reference 318312 as a 22 mm equal tee. Equal means the nominal connection size is the same at all three ports; it does not mean every other fitting feature or service condition is interchangeable. Confirm the actual supplied reference, pipe suitability, components and required quantity. Photograph scale, nut width and perspective are not substitutes for a labelled item.

Check an unequal tee without guessing its port order

Reference 318415 appears under the maker's “Reducing Tee — End” heading with the listed sequence 22 mm × 15 mm × 22 mm. Keep that exact reference and category together when asking about the product. Do not convert the sequence into left, right or branch dimensions without a labelled manufacturer drawing or confirmation of the supplied fitting’s ports.

This matters when a parts list uses only “22/15 reducing tee.” That description leaves out whether the reduction belongs on the branch, one run end or another arrangement. A matching total of large and small connections may still route the wrong size to the intended pipe. Resolve the omission before choosing a substitute.

Send a port schedule rather than an ambiguous abbreviation

A practical enquiry states “run end A: required size; run end B: required size; branch: required size,” followed by the proposed maker reference. Include the pipe specification and intended service for the person checking suitability. Ask APM to confirm the supplied model, actual sale quantity and included components. Do not infer a retail pack from a catalogue trade-bag quantity or from the number of nuts visible in a picture.

Manufacturer reference and next step

The Embrass Peerless September 2024 product guide, printed page 39, provides the separate tee categories. Use those labels to make an accurate order; have the exact current part, port mapping and suitability confirmed before buying. This guide supplies no assembly, sealing or testing procedure.

Help choosing before you order

Send the required fitting reference and a clear description of the connection to APM on WhatsApp: 020 8702 8080 or 07737 263641. Confirm the supplied part, contents and sale quantity before ordering. Check the delivery information for current options and terms.