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Valterra P23402LF 1/2 in. MPT x FPT Lead-Free Brass Check Valve for RV Water Systems

Valterra P23402LF 1/2 inch MPT x FPT Lead-Free Brass Check Valve for RV water system backflow prevention, 2.3 inch length
Valterra 1/2" MPT x FPT Lead Free Brass Check Valve
 
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Part Number: P23402LF
Manufacturer: Valterra

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Valterra Lead-Free Brass 1/2" MPT x FPT Valterra P23402LF -- 1/2" Lead-Free Brass Check Valve for RV Water Systems

Protect your RV fresh water supply from antifreeze backflow during winterization and dewinterization. The Valterra P23402LF is a compact, lead-free brass check valve with 1/2" male-to-female threaded connections that installs directly into standard RV water lines, water pump outlets, and winterization bypass plumbing.

One-Way Flow Protection for Your RV Water Lines

When you pump antifreeze through your RV plumbing system each fall, the last thing you want is that fluid reversing course and contaminating the fresh water side of your system. The P23402LF installs inline with 1/2" NPT plumbing -- the water flow is designed to travel from the male (MPT) inlet to the female (FPT) outlet, and the internal check valve prevents any reverse flow.

Built from solid lead-free brass, this valve meets modern NSF/ANSI 61 compliance requirements for potable water contact -- important any time a fitting is anywhere near your drinking or cooking water supply. At just 2.3" in length and 0.18 lbs., it fits cleanly in tight under-sink or wet-bay plumbing runs without requiring extra support.

Lead-Free Brass Body

Solid brass construction meets lead-free standards for potable water system use -- no concerns about leaching near your fresh water supply.

1/2" NPT Threaded Connections

Male NPT inlet and female NPT outlet thread directly onto standard 1/2" RV water line fittings and pump ports -- no adapters needed in most installs.

One-Way Flow Design

Internal check mechanism allows flow from MPT to FPT only, blocking reverse flow of antifreeze, backpressure, or contaminated water.

Compact Inline Form Factor

At 2.3" long and under 0.2 lbs., this valve fits in confined wet-bay and under-sink spaces without rerouting existing plumbing runs.

Where RVers Typically Install This Valve

The P23402LF is most commonly used in the following RV plumbing locations:

  • Water pump outlet: Prevents antifreeze pumped through the system from flowing back through the pump inlet into the fresh tank.
  • Winterization bypass lines: Installed on antifreeze inlet lines to ensure one-directional flow during pump-in winterization procedures.
  • City water inlet plumbing: Can serve as a backflow preventer between the city water connection and the internal supply lines.
  • Hot water heater bypass kits: Often used alongside bypass valves to control flow direction when bypassing the water heater during winterization.
Lead-Free for Potable Water Use: This valve is constructed of lead-free brass, making it appropriate for use anywhere in your RV fresh water system -- not just in gray water or drain applications.

Winterization and Dewinterization Tips

A check valve is a small part that does a big job at the end of camping season. Here is how to get the most out of the P23402LF:

  • Install the valve so the MPT (male) end faces the antifreeze source -- the internal check seats on backpressure from the FPT side.
  • Use thread seal tape (PTFE) on the MPT threads before installation to prevent seeping at the joint under pump pressure.
  • During dewinterization, flush the valve with fresh water -- check valves do not require seasonal removal or rebuilding in normal use.
  • Inspect the valve body for mineral deposits or discoloration each spring; brass is durable but hard water can cause buildup at the seat over several seasons.
Thread Standard -- NPT vs. NPS: This valve uses NPT (National Pipe Taper) threads, which are the standard for RV water system fittings. NPT threads are tapered and seal with thread tape or compound. Do not attempt to connect to NPS (straight) threaded fittings without an appropriate adapter.
Maintenance Note: Check valves can accumulate debris at the seat over time, especially in RVs that use well water or non-filtered sources. If you notice reduced flow or failure to seal, inspect the seat for sediment before replacing the valve.

What Is Included

  • 1x Valterra P23402LF 1/2" MPT x FPT Lead-Free Brass Check Valve

Thread seal tape and installation tools are not included.

Part Identification

ManufacturerValterra
Part NumberP23402LF
SKU10-0166
UPC019079244024

Physical Specifications

Body MaterialLead-free brass
Overall Length2.3 in.
Weight0.18 lbs.
Valve TypeInline check valve (one-way)

Connection Specifications

Inlet Connection1/2" MPT (Male NPT)
Outlet Connection1/2" FPT (Female NPT)
Thread StandardNPT (National Pipe Taper)
Flow DirectionMPT inlet to FPT outlet only

Ratings and Compliance

Lead-Free CompliantYes -- lead-free brass construction
Suitable for Potable WaterYes
Warranty1-year limited manufacturer warranty

Common Applications

Primary UseRV water system backflow prevention
Winterization UseAntifreeze pump-in line isolation
Compatible Systems1/2" NPT RV fresh water plumbing
Typical Install PointsPump outlet, bypass lines, city water inlet
Important Information
  • This valve is designed for one-directional flow only -- flow must enter at the MPT (male) end and exit at the FPT (female) end. Reverse installation will block all flow.
  • Always use PTFE thread seal tape on NPT threads before installation to prevent leaks under pump pressure.
  • Do not exceed the pressure rating of your existing RV water system plumbing when using this valve inline.
  • Thread seal tape and installation tools are NOT included -- purchase separately.
  • Verify your existing fittings are NPT (tapered) before installation -- straight-thread NPS fittings require an adapter and will not seal with tape alone.
  • This valve prevents backflow but does not replace a pressure regulator -- always use a city water pressure regulator at the hookup inlet when connected to campground water supplies.
⚠️ WARNING: This product can expose you to one or more chemicals known to cause cancer and/or birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov

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