Project Description

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  • FR2_upright
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Installation Instructions

Dranjer FR2

Drain Retrofit

The F Series Dranjer products are designed to be used in homes where ASD has been, or may be, included as a radon mitigation technique. These valves will not open at less than 0.9” of negative pressure yet allow for water flow.

FR2 is a retrofit model designed for floor drains.

A flexible rubber flange attaches to the hard plastic portion of the seal. Hold the Dranjer under the existing strainer plate. Push the strainer plate with the FR2 back into the drain opening. Friction among the sides of the strainer plate, the Dranjer, and the ring in the floor holds the Dranjer™ under the cover plate. Trim off the rubber that extends past the ring. You have retrofitted the Dranjer in existing construction.

Fits drain pipes larger than> 2> 5.08
Below Grade Depth3.258.255
Below Grade Width1.74.318
Flange Diameter820.32
Spec Sheet
F series drainage diagram

How Your Dranjer F Series Works

F Series have a sealing ring that lifts when water enters the valve – allowing for the water to flow through the unit.

In a no flow environment, the sealing ring prevents radon gas from passing through or past the unit. This effectively reduces radon levels in the dwelling.

Dranjer products are engineered and laboratory and field tested. Dranjer products are DIY friendly. Dranjers are often installed in association with an ASD system but may be the only action you need to reduce your radon levels.

Suitable with ASD Systems

F Series Dranjer products are suitable for use with typical residential Active Sub Slab Depressurization (ASD) installations.

The valve in these Dranjer products will not open until static pressure across the Dranjer exceeds 0.75 inches of water column (185 Pa). Typically, ASD systems directly connected to sump pits or weeping tile systems operate below these pressures.

If ASD system suction pressure in a sump pit or weeping tile system does exceed these levels, some air will flow through the Dranjer unit, from the protected space into the sump pit or weeping tile system, and then to the ASD fan. In these applications, it is recommended F Series Dranjers are used. They offer greater resistance to airflow.

In most applications, air leakage through the Dranjer from the residence will have little or no impact on the effectiveness of the ASD system.

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