PVC discharge tubing 14 x 18 mm per metre, ref. COZ-14-18

PVC evacuation tube 14 x 18 mm, per metre

Flexible PVC tubing intended for discharge lines in a water treatment installation. Internal diameter 14 mm, external diameter 18 mm, wall thickness 2 mm. Sold cut to length, per metre: you order the exact length for your site, without having to stock an entire roll.

What it is used for on an installation

This is a discharge line, not a supply line. Common applications:

• Softener regeneration discharge to drain or siphon
• Salt tank overflow, mandatory safety against overflow
• Purging and draining of filter housings and pre-filtration units
• Concentrate discharge from small reverse osmosis units, depending on original connection

The 14 x 18 is the standard size on most single-unit systems and cabinet softeners on the market, making it the reference size to keep in stock on your vehicle.

Discharge, not pressure

Important distinction: this tube is designed for free discharge, open to air or with slight back-pressure. It does not replace a pressurised supply tube and must never be installed between the water inlet and the equipment. For the pressurised section, use the tubing and fittings specified for that purpose.

Installation rules to observe

Air break mandatory. The discharge must never be connected directly and sealed to the drain. A break in charge, a funnel or an air-break siphon is required to prevent any backflow of waste water to the equipment. This is a network protection requirement and the first point any inspection will check.

Continuous slope. The tube must descend regularly towards the discharge point. A low point will trap water, which stagnates, becomes colonised and eventually blocks or backs up.

No crushed bends. Flexible PVC pinches easily in a tight angle or under an over-tightened clip. At the valve outlet, allow a wide radius and secure with clips positioned without crushing.

End held in place. At each regeneration the flow starts suddenly and the tube recoils. The end must be clamped in the discharge, otherwise it comes out and sprays the room.

Short useful length. The longer the line and the higher it rises, the greater the back-pressure and the more the regeneration cycle degrades. Keep it as short as possible and check the maximum discharge height allowed by the valve.

Good to know before ordering

Measure the actual route, from the valve outlet to the discharge point, accounting for drops and detours, then add a margin for final securing. Since the tube is cut per metre, it is better to have one metre too much than twenty centimetres too little.