Anti-Leak Irrigation Fittings: How They Work and Which to Use

Most leaks in a garden watering system don't come from the pipe. They come from the joints. A standard push-on fitting relies on the pipe gripping a barb, and that grip loosens as the pipe warms in the sun, gets tugged at a corner or takes a pressure spike every time the timer opens. Anti-leak fittings fix that with a compression nut that clamps the pipe onto the barb, so the joint stays sealed.

This guide explains how they work, which fitting does which job, and how to fit them.

How anti-leak fittings work

Each fitting has a barb, like a normal push-on fitting, plus a threaded nut. You slide the nut over the pipe, push the pipe fully onto the barb, then screw the nut down. The nut squeezes the pipe onto the barb all the way round, so it can't blow off or weep.

• No tools. Every nut is tightened by hand. Don't use a spanner, as it can crack the nut.
• No hot water. You don't need to soften the pipe to get it on.
• They come apart. Unscrew the nut and pull the pipe off to move a fitting, reuse it or flush the line.
• They fit most 13mm pipe. The 13mm fittings suit 1/2" supply pipe, 13mm inside and 16mm outside diameter, including Hozelock, Claber, Gardena and Rain Bird pipe.

Where push-on fittings usually fail

If you've had fittings pop off before, it was almost certainly at one of these points:

• At the tap. The first joint takes full mains pressure every time the water comes on. The anti-leak tap/timer connector screws onto a 3/4" BSP tap or timer outlet and clamps the pipe.
• At corners. Pipe pulled tight round the edge of a bed or up a wall puts constant strain on the joint. The anti-leak elbow holds the bend.
• At the end of the line. Push-in plugs can pop out under pressure. The anti-leak end stop stays on, and unscrews when you want to flush grit out.
• Anywhere the pipe gets walked on or tugged, such as across a path or beside a lawn edge.

Which fitting does what

Laying out the 13mm supply pipe

• Tap/timer connector: from the tap, timer or pressure reducer to the pipe.
• Tee: takes a second run off the main pipe, for example down the other side of a border or into a greenhouse.
• Elbow: a 90° turn at a corner.
• Straight joiner: joins two lengths, or repairs a cut or split pipe.
• Flow control: turns one run down or off without touching the rest, to balance the system or isolate a section.
• End stop: closes the end of the pipe.

Feeding pots and baskets with 4mm micro tube

• In-line connector with 4mm outlet: joins the 13mm pipe and takes a micro tube off at the same point. It can be buried under soil, bark or mulch.
• In-line connector with twin 4mm outlets: the same, with two micro tubes.
• Multi-outlet connector: four 4mm outlets from one point, with caps for any you don't need yet. It's a neat way to feed a group of pots or a raised bed, and there's no hole to punch.

Watering the plants

The anti-leak vortex dripper fits on the end of a 4mm micro tube with an anti-leak nut. It spins the water out in an even spray round the plant, and you twist the cap to set anything from off to 40 litres an hour. That means one dripper can give seedlings a gentle drip or a big pot a good soak.

Keeping it clean

The Claber 91011 anti-leak filter fits in-line on 13mm pipe near the start of the system. The mesh unscrews for rinsing, and it stops grit reaching your drippers and sprays.

Everything in one box

The 16-piece anti-leak fittings kit has 2 tap/timer adapters, 4 tees, 2 elbows, 4 straight joiners, 2 flow controls and 2 end stops. Add the length of 13mm pipe you need and you have a system that's sealed the same way from tap to end stop.

How to fit them

1. Lay the pipe out first and mark where each fitting goes.
2. Cut the pipe square with a sharp knife or pipe cutter.
3. Unscrew the nut and slide it over the end of the pipe.
4. Push the pipe fully onto the barb. It needs to go all the way on, not just over the first ridge.
5. Screw the nut down hand-tight.
6. Run the water and check every joint before you bury anything or cover it with mulch.

At the tap end, fit things in this order: the tap, a tap splitter if you need one, the timer, then the pressure reducer and filter. Then connect the pipe with the anti-leak tap/timer connector.

Can I mix them with my existing fittings?

Yes. The 13mm anti-leak fittings suit standard 13mm supply pipe, so you can use them alongside the fittings you already have. Many people start by replacing the joints that keep failing, usually at the tap and at corners, and leave the rest as they are.

Anti-leak or push-on: which should I buy?

• Choose anti-leak for the tap joint, corners, buried joints, anywhere the pipe gets walked on, and any system on mains pressure. They're also easier to change later, as they come apart by hand.
• Push-on fittings are fine for short, low-pressure runs that stay put, especially with a pressure reducer in the system and ratchet clips on the joints.

See the full range in our anti-leak irrigation fittings collection, or read more on how anti-leak fittings work. If you're not sure which pieces you need, call us on 0333 335 6295 and we'll help you plan it.