PVC transparent tubing 12 x 16 mm, 2 mm wall thickness, sold per 50 m - ref. BOST-0501528

PVC discharge tube 12 x 16 mm, per metre

Flexible PVC tubing for discharge lines in water treatment installations. Inner diameter 12 mm, outer diameter 16 mm, wall thickness 2 mm. Sold by the metre: order the exact length you need for your site, without storing 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 12 x 16 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.

Drainage, not pressure

Important distinction: this tube is designed for free drainage, 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 appliance. For the pressurised section, use the tubing and fittings specified for that purpose.

Installation rules to follow

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

Continuous slope. The tube must slope regularly towards the discharge point. A low point traps 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 secured. During each regeneration cycle 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, including drops and detours, then add a margin for final securing. Since the tube is cut by the metre, it is better to have one metre too much than twenty centimetres too little.