Flexible Tap Connectors: How to Choose the Right Size and Length

A flexible tap connector — sometimes called a braided hose or flexi hose — connects the tap tail to the supply pipework under the sink or basin. Every tap installation needs them. The challenge is that they come in half a dozen combinations of end fitting size, pipe diameter, and length, and choosing the wrong one means a second trip to the merchant. This guide covers the full Embrass Peerless range at APM and gives you a decision framework for getting it right first time.

Shop flexible tap connectors: Browse flexible hoses by connection size and length, or ask APM to help match your existing connector.

The Three Measurements You Need Before Buying

A flexible tap connector has two ends. Before you order, identify:

1. The pipe size — the diameter of your supply pipework. Standard domestic plumbing uses 15mm copper. Older or commercial systems may use 22mm.
2. The connection at the tap — check the tap instructions and the existing fitting before ordering. BSP connections and metric monobloc tap tails are different: a monobloc tap body may need M10 or M12 male tails. Identify the actual thread and sealing arrangement; the size of the nut is not the thread size.
3. The length needed — measured from the compression nut on the pipe to the tap tail. Allow for any offsets. Available lengths are 150mm, 300mm, 500mm, and 900mm.

The Full Range: 15mm Connections

15mm is the standard for virtually all domestic basin, bath, and kitchen tap supplies. The compression end fits directly onto 15mm copper or push-fit pipework.

½" BSP tap tail (the most common)

Use a ½" BSP connector only where the mating tap connection is specified as ½" BSP. For a hose that screws directly into a monobloc tap body, check the metric tail size below.

• 15mm × ½" × 150mm — — for connections where the tap tail and pipe are very close together. Tight vanity units and wall-hung basins.
• 15mm × ½" × 300mm — — the default length. Fits the vast majority of standard kitchen sinks and pedestal basins where the pipe rises to within 30cm of the tap tail.
• 15mm × ½" × 500mm — — where the supply pipe enters at a lower point, vanity units with cabinet depth, or where the tap position makes a 300mm hose pull tight.
• 15mm × ½" × 900mm — — for unusual layouts: pipes entering from floor level, tall vanity units, or any installation where the hose needs to run around an obstacle.

¾" BSP tap tail

¾" BSP is used on bath taps (pillar and mixer), large kitchen mixer taps, and some commercial fittings.

• 15mm × ¾" × 150mm —
• 15mm × ¾" × 300mm —
• 15mm × ¾" × 500mm —
• 15mm × ¾" × 900mm —

3/8" BSP tap tail

3/8" BSP appears on some continental taps, older UK basin taps, and some designer ranges. Less common but worth knowing.

• 15mm × 3/8" × 300mm —

The Full Range: 22mm Connections

22mm compression connections are used on bath mixer taps with a 22mm supply, on higher-flow shower mixer valves, and on some commercial installations.

• 22mm × ¾" × 150mm —
• 22mm × ¾" × 500mm —
• 22mm × ¾" × 900mm —

Connectors with Built-In Isolation Valve

These combine a flexible hose and an isolation valve in one fitting — the compression nut connects to the pipe, the valve body is mid-hose, and the tap tail fitting is at the other end. Useful when retrofitting taps to existing pipework that has no isolation valve, or for tight spaces where fitting a separate iso valve and hose would be awkward.

• 15mm × ½" × 300mm with Iso Valve — — more than the standard hose, gives you isolation for future maintenance without a separate valve fitting.
• 15mm × ¾" × 300mm with Iso Valve —

Monobloc Taps: Check M10 or M12 Before Ordering

Monobloc tap tails screw into the tap body and can have different metric threads, including M10 and M12. Do not choose by tap brand alone: check the exact tap model, male thread, sealing arrangement, supply-end connection and required hose length. If the size is unclear, use the tap instructions or ask APM to help identify the connection before ordering.

• View the MasterFlow mono basin connector listing — confirm its connections against the instructions for your exact tap before buying.
• M12 male × 15mm compression × 300mm Embrass Peerless tap tails, sold in pairs — an option where those exact connections and length match your installation; not an interchangeable substitute for M10.

Decision Guide: Which Connector for Which Tap?

Installation Notes

• Check how each joint seals. Follow the tap and connector manufacturer’s instructions for the specified washer, O-ring or thread seal. Do not apply a blanket PTFE-tape rule to every connection.
• Follow the specified tightening method. Use the instructions for the exact tap and connector rather than a universal extra-turn rule; avoid overtightening.
• Check the olive. The compression end uses an olive — ensure it is seated squarely before tightening. A skewed olive will leak immediately or fail within weeks.
• Check for kinks. After fitting, route the hose without sharp bends. A kinked braided hose restricts flow and fatigues the inner tube.
• Replace, don't patch. Flexible connectors that show corrosion on the braiding, any weeping at the end fittings, or are over 10–15 years old should be replaced. They are inexpensive insurance against a significant under-sink leak.

Check each product listing for current availability and whether it is sold singly or as a pair. If you need help matching a connector, contact our Acton trade counter before ordering.

APM Plumbing & Electrical | 24 Western Avenue, Acton, London W3 7TZ | 020 8702 8080 | apmi.uk