---
product_id: 296767091
title: "Internal Backwater Valve,4-F 4\" Float Model Flood-Guard for 4-inch Flood Drains,Drain Backflow Preventer for Sewer Flood Protection"
brand: "minimprover"
price: "$58.27"
currency: USD
in_stock: true
reviews_count: 8
url: https://www.desertcart.us/products/296767091-internal-backwater-valve-4-f-4-float-model-flood-guard
store_origin: US
region: United States of America
---

# 4-inch drain fit precision Float-activated backflow seal Solid brass durability Internal Backwater Valve,4-F 4" Float Model Flood-Guard for 4-inch Flood Drains,Drain Backflow Preventer for Sewer Flood Protection

**Brand:** minimprover
**Price:** $58.27
**Availability:** ✅ In Stock

## Summary

> 🚨 Don’t wait for the flood—secure your space with smart backflow defense!

## Quick Answers

- **What is this?** Internal Backwater Valve,4-F 4" Float Model Flood-Guard for 4-inch Flood Drains,Drain Backflow Preventer for Sewer Flood Protection by minimprover
- **How much does it cost?** $58.27 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.us](https://www.desertcart.us/products/296767091-internal-backwater-valve-4-f-4-float-model-flood-guard)

## Best For

- minimprover enthusiasts

## Why This Product

- Trusted minimprover brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Effortless Installation:** Just a screwdriver and minutes to flood-proof your space
- • **Precision Fit for 4" Drains:** Engineered specifically for standard 4-inch flood drains—no guesswork
- • **Premium Corrosion Resistance:** Solid brass body built to last through years of moisture exposure
- • **Smart Float Valve Technology:** Automatically seals off sewer backflow to protect your property
- • **Reliable Seal with Molded Rubber Gaskets:** Soft yet durable gaskets ensure a tight, slip-free barrier

## Overview

The Minimprover 4" Float Model Flood-Guard is a robust internal backwater valve designed to prevent sewer backflow and flooding. Crafted from solid brass with molded rubber gaskets, it fits standard 4-inch flood drains and installs easily with just a screwdriver. Its float-activated mechanism automatically seals the drain during sewer overloads, protecting your property from costly water damage and messy cleanups.

## Description

Internal Backwater Valve,4-F 4" Float Model Flood-Guard for 4-inch Flood Drains,Drain Backflow Preventer for Sewer Flood Protection

## Features

- ★ 【Material】: The main parts are made of solid brass which is durable and corrosion resistant.The gaskets are made of molded rubber which is soft and durable.
- ★ 【SIZE】: 4-F 4" Float Model Flood-Guard for 4-inch Flood Drains! Please check the size of drain tube before buying!
- ★ 【Introduction】: Flood-Guard operates like a check valve to seal off water back-up caused by overloaded sewers. Water flows normally through the drain until the sewer begins to back up. Then the Flood-Guard float rises to seal off the drain opening until the water recedes.
- ★ 【Adventage】: A screwdriver and a couple of minutes are all you need to install a Flood-Guard. Once in place, it can prevent property damage and a very messy clean-up job.
- ★ 【Package Include】: 1Pack 4" Float-guard Model Flood-Guard.

## Technical Specifications

| Specification | Value |
|---------------|-------|
| Material | Brass, Rubber |
| Brand | Minimprover |
| Exterior Finish | Brass |
| Inlet Connection Size | 4 Inches |
| Number of Ports | 2 |
| Outlet Connection Size | 4 Inches |
| Manufacturer | Minimprover |
| UPC | 779880498541 |
| Part Number | H087-4 |
| Item Weight | 12.6 ounces |
| Package Dimensions | 4.06 x 4.02 x 3.66 inches |
| Item model number | H087-4 |
| Size | 4" Flood-Guard |
| Batteries Included? | No |
| Batteries Required? | No |

## Product Details

- **Material:** Brass, Rubber
- **Brand:** Minimprover
- **Exterior Finish:** Brass
- **Inlet Connection Size:** 4 Inches
- **Number of Ports:** 2
- **Outlet Connection Size:** 4 Inches
- **Manufacturer:** Minimprover
- **UPC:** 779880498541

## Images

![Internal Backwater Valve,4-F 4" Float Model Flood-Guard for 4-inch Flood Drains,Drain Backflow Preventer for Sewer Flood Protection - Image 1](https://m.media-amazon.com/images/I/61l9DzIp9kL.jpg)

## Available Options

This product comes in different **Size** options.

## Customer Reviews

### ⭐⭐⭐⭐⭐ A+ rating
*by J***. on April 8, 2024*

A+. I deal with basement back ups when the city streets flood. Sump pump is fine, storm sewer is issue a backflow valve in the yard would cost thousands to install. This worked great so far in my basement. Last time I would’ve had an issue it barely let any water seal past the gasket edges. Usually I’d have 2-4” in the basement under these circumstances. I can probably tighten it a little more again, but it was very tight to begin with. Hold it with 1 hand and start screwing the 4 screws in a circle. Once snug you can crank it tight. Lean edges as best as possible. Mine was cast iron so hard to clean. Fit well. Works well. Also best one I’ve seen to allow water to go in, and not clog it up.

### ⭐⭐⭐⭐⭐ This is a very good item. Priced very fairly. Well made.
*by D***. on March 21, 2025*

This is excellent. I replaced one that I had for years but corroded. The key to using these is to put it down into the PVC tube just far enough that the center "pin" sticking up is about 1/4 inch below the level of the floor. This is made well, is a quality item, and is easy to install. I may buy another one so that in 20 years when this one is all nasty, I can replace it easily.

### ⭐⭐⭐⭐ 2" Model Poorly Designed - Requires Modifications
*by C***N on February 7, 2022*

The 2" model is a much poorer design than the others. Because it uses only 2 screws instead of 4 it is very easy to accidently get the rubber O-Ring misaligned and then you have to start the whole process over again. Be very careful when inserting this and tightening it to get it perfectly straight in the drain!It comes fully tightened and will not fit in your drain in this config. You need to almost fully loosen the two side screws. The O ring will then get sucked a bit into the sides of the device.The main problem however is that the spring is simply WAY too strong. I suspect they used the same spring and design from the larger models which would have much more water on top compressing it down. To make this work you will need to:1. Cut a few coils off the spring. This depends on how far down you can insert the device (farther is generally better as there will be more water weight on top to open it). Make sure you are ABOVE any kind of standard P trap!2. Once you cut off coils from the spring the spring will now not go the full length of the screw. You need to buy some very small washers to fill this gap.3. Tune the tension of the spring and the amount of washers with the device MOSTLY tightened. As you tighten the device it changes the length and therefore the amount of seal the float will make. If you decide on the amount of washers when it is fully loosened you will be in for a bad time when the float now no longer seals via the spring.I used in total about 5 washers after a lot of experimentation and I cut maybe 4 coils approximately off the spring. I tied a small string to the middle bar of the device in two places (on either side of the screw) so I could lower it evenly. Make sure to carefully tighten each side evenly and if it gets at all misaligned / angled within the pipe start over. If its angled then its not going to form an air tight seal. I also put lasco pure silicone grease over the O-Ring and the float to make sure it sealed better (only use pure silicone grease). And make SURE you lean the crap out of the inner wall of the pipe you are lowering into - I used a wire brush. I was only able to insert it a maximum of about 8 inches down but this setup now works great for me. No more sewer gas smell and hopefully no more backups!

## Frequently Bought Together

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*Product available on Desertcart United States of America*
*Store origin: US*
*Last updated: 2026-02-02*