Nelsen WS3 DLFC Assembly NPT

Nelsen WS3 DLFC Assembly with NPT connection is the drain-line flow control group that meters backwash and rinse flow on 3-inch WS3 commercial control valves.

• Drain Line Flow Control (DLFC) assembly for the Nelsen WS3 3" valve platform
• NPT (National Pipe Thread) drain outlet for threaded pipe or fitting connection
• Holds backwash flow to a fixed rate so the media bed lifts and rinses correctly
• Part of the valve's drain circuit during regeneration and backwash cycles
• Shipping weight roughly 2.8 kg, reflecting the larger commercial-scale body
• Genuine Nelsen replacement part matched to the WS3 valve series

Use this assembly when servicing a large-diameter WS3 system and the existing drain-line flow control is worn, cracked, or fouled, or when converting the drain to an NPT-threaded connection. Correct DLFC sizing is what keeps a commercial media bed backwashing at the flow it was designed for, so match the assembly to your original valve build before installing.

Controlling the backwash flow

The WS3 DLFC (drain-line flow control) assembly with NPT connection sets the precise drain flow rate during a control valve's backwash and rinse cycles. That fixed flow is what fluidizes and cleans the media bed properly: too little and the bed never lifts to rinse out trapped debris, too much and media can wash down the drain. The correct DLFC keeps regeneration efficient and protects your media.

Service notes

DLFC buttons and assemblies are matched to a valve's tank size and media, so replacing a lost, cracked, or wrong-rate assembly with the correct part is essential to good performance. This unit is built for the Nelsen WS3 platform with a standard NPT drain fitting. If you are not certain which flow rate your system calls for, share your tank size and media and we will confirm the right assembly.

Why the right flow rate matters

Every media type and tank diameter has a target backwash rate, and the DLFC is what enforces it. Fitting the correct assembly protects the investment you have made in resin or filtration media, keeps regeneration water use predictable, and prevents the two failure modes of a poorly matched drain control: a bed that never fully cleans, and media slowly lost down the drain.