Tank Outlet Kit 1000L with Valve, 30 mm Hose Barb Elbow and Cap

The tank outlet that delivers flow, and closes twice. Bulkhead fitting, ball valve, 30 millimetre hose barb elbow and screw-on cap, supplied together for a 1000-litre tank. It is the largest diameter in the range and the only kit to offer a back-up closure.

Flow, and why 30 millimetres is not a detail

Between a 20 millimetre outlet and a 30 millimetre one, the gap is not one and a half times as you might imagine : flow follows the cross-section, hence the square of the diameter. A 30 millimetre section lets through more than double what a 20 millimetre section lets through. On a thousand litres to transfer, that is not counted in minutes but in tens of minutes.

That is why this kit exists alongside the others. It is not "better", it is made for a different job : emptying, transferring, filling a mobile cistern, feeding a pump that demands water at its inlet. For watering with a jet, a more modest diameter is amply sufficient and costs less.

The elbow is turned 90 degrees downwards, and this choice has a mechanical reason. A pipe connected straight pulls on the valve horizontally, and it is that overhang which ends up fatiguing a plastic thread. With an elbow, the pipe drops naturally along the tank : its weight bears downwards, not outwards, and it does not form a loop that gets crushed against the frame.

The cap, the part whose point you grasp too late

This kit is the only one in the range supplied with a closing cap that screws on in place of the pipe. Many consider it superfluous on opening the box. Yet it solves three very real problems, and none shows up until it has happened.

• A valve is not eternal. A seal that ages, a quarter turn not fully closed, a lever caught by a passing wheelbarrow : the cap is the second barrier that turns an incident into a non-event.
• Critters. A hose barb left open is an ideal shelter : wasps, spiders, slugs. You find the outlet blocked on the first use of spring.
• Winter. When closed, the cap stops residual water from stagnating in the elbow and freezing, blocking the passage.

The habit to adopt is simple : as soon as the pipe is disconnected, the cap goes back on. It screws on by hand in two seconds, without tools, and it does not get lost if you leave it permanently on the elbow while the pipe is working. After a few weeks the movement becomes automatic, and that is exactly when it will spare you an unpleasant surprise : tank leaks never happen when you are standing in front of it.

How it holds without screwing anything on the inside

It is the question everyone asks on discovering the Quick Joint bulkhead fitting : if there is no nut on the other side of the wall, what holds the whole thing ? The answer lies in the black rubber sleeve around the body, and the mechanism deserves thirty seconds of explanation because it decides the reliability of the assembly.

By screwing on the outer ring, you compress this sleeve lengthwise. Rubber being incompressible, it can only do one thing : swell in diameter. It then presses against the edge of the hole and spreads onto the inner face of the wall, which it sandwiches with the outer flange. The seal therefore does both jobs at once : it holds mechanically and it seals. The more you tighten, the more it presses.

On this kit in particular, that is just as well. A 30 millimetre outlet means a flow that works and a full pipe that weighs at the end. An assembly that bears on the whole circumference of the hole absorbs these loads better than two rigid seats clamped against each other, and it tolerates the small irregularities of a hand-drilled hole.

One single warning, and it comes from the manufacturer : the tightening must stay light. You tighten by hand until you feel resistance, then you stop. Forcing with a wrench does not make the assembly any more watertight, it cracks the plastic body — and a crack only shows once the tank is filled.

Choosing within the range

The three kits fit the same 43 millimetre hole in the wall of a 1000L tank and share the same bulkhead fitting. What changes is the outlet, and it is the only criterion that really matters when choosing : the rest of the assembly is strictly identical from one model to the next.

If you are hesitating between the 25 and the 30, ask yourself a single question : are you going to transfer the whole tank, or draw from it with a bucket and a jet ? In the second case, the 30 is diameter paid for nothing, and the cap will not serve you any better. In the first, on the other hand, it is the time you spend waiting in front of the tank that makes the difference, and the choice is quickly made.

What is in the box

The four parts are supplied separately. The cap screws onto the elbow, not onto the valve : get into the habit of leaving it permanently on the barb when the pipe is connected, it is the best way not to be looking for it six months later. No adapter needs to be planned for, the threads match.

Characteristics