F311 - Drain Saddle Clamp for RO Waste Pipe Connection 1/4" Tubing

The F311 is a drain saddle clamp that connects 1/4" reverse osmosis waste tubing onto a standard 40mm waste pipe, giving your RO system a permanent, tidy drain connection. It clamps around the outside of the waste pipe over a small drilled entry point, so there's no need to cut the pipe or fit a separate tee. WrekinWater supplies this clamp for anyone plumbing in a new RO system or replacing a damaged or missing waste connection.

When you need this fitting

• You're installing a new RO system and need a proper waste connection instead of a loose tube.
• Your existing saddle clamp has cracked, split, or is leaking at the pipe.
• You're moving or extending the drain run and need a fresh take-off point.
• You want a neater, code-appropriate connection instead of pushing tubing straight into a hole in the pipe.

An RO system's drain line runs on and off almost continuously while the unit is producing water, so a loose or improvised connection to the waste pipe is one of the most common causes of a slow drip or damp cupboard under the sink. The F311 saddle clamp grips the waste pipe securely and holds the 1/4" tubing at a fixed, sealed point, keeping the connection watertight even under the intermittent pressure of the drain flow.

WrekinWater is a family run water treatment company based in Bettisfield, Shropshire, with more than 50,000 customers served over 15 years and an Excellent rating on Trustpilot. We stock small fittings like this saddle clamp alongside full RO systems, so you can get everything needed for a tidy installation in one order.

How to fit it

1. Choose a straight, accessible section of 40mm waste pipe for the connection point.
2. Drill a small pilot hole through the pipe wall at the chosen spot.
3. Position the saddle clamp over the hole and tighten the retaining screws evenly.
4. Push the 1/4" RO waste tubing into the clamp's push-fit connector until it seats fully.
5. Tug-test the tubing gently to confirm it's held securely.
6. Run the RO system briefly and check the joint for any weeping before leaving it unattended.