3P Technik Calmed Inlet DN100 / DN125 – Sediment Protection for Rainwater Tanks

The 3P Technik Calmed Inlet is an in-tank fitting designed to protect the quality of stored rainwater by preventing the disturbance of settled sediment layers at the base of the tank whenever fresh water enters from the downpipe or filter system. Fitted to the inlet pipe at the base of the storage tank, the Calmed Inlet disperses incoming water slowly and gently across the floor of the tank rather than allowing it to drop forcefully onto settled silt, leaves, and debris — which would otherwise stir sediment back into suspension and degrade the clarity and quality of the stored water.

How the Calmed Inlet Works

As filtered rainwater enters the storage tank via the inlet pipe, the Calmed Inlet's specially designed body distributes the flow horizontally and at low velocity across the tank base. This gentle dispersal keeps settled sediment layers undisturbed, allowing particles to remain at the bottom of the tank where they cause no harm and are not drawn into the pump or distribution system. Simultaneously, the inlet design ensures a continuous and gentle oxygenation of the lower water column — supplying dissolved oxygen to the deepest part of the stored water and preventing the anaerobic conditions that can cause water to become stagnant, odorous, or biologically active during long storage periods.

Technical Specification

• Inlet pipe sizes: DN100 (110mm OD) and DN125 (125mm OD)
• Function: laminar low-velocity water inlet with sediment protection and oxygenation
• Installation: fitted to the inlet pipe at the base of the storage tank
• Compatible with PE, GRP, and concrete rainwater storage tanks
• Designed for use with 3P Technik tank filters and Overflow Siphon Uno
• Material: durable polyethylene (PE)

Applications and Usage

The 3P Technik Calmed Inlet is a recommended component in all 3P Technik Rainwater Harvesting Filter Kits (A, B, and C) and is equally suitable for installation in new or existing rainwater harvesting systems. It is used in underground rainwater tanks, above-ground utility tanks, and large commercial or agricultural collection systems where water quality and long-term storage hygiene are priorities. By protecting settled sediment from disturbance and maintaining dissolved oxygen levels in the lower water column, the Calmed Inlet contributes significantly to the microbiological quality and usability of stored rainwater for non-potable applications including toilet flushing, garden irrigation, vehicle washing, and industrial process water.

Learn more about 3P Technik products here.