---
product_id: 513280063
title: "DONGKER 2 PCS CO2 1 Way Check Valves,CO2 Stainless Steel Non-Return Check Valve for CO2 Line 4/6mm Tubing Regulator Diffuser Aquarium CO2 Systems"
brand: "dongker"
price: "€ 26.13"
currency: EUR
in_stock: true
reviews_count: 8
category: "Dongker"
url: https://www.desertcart.nl/products/513280063-dongker-2-pcs-co2-1-way-check-valves-co2-stainless
store_origin: NL
region: Netherlands
---

# Prevents water backflow Fits 4/6mm CO2 tubing Stainless steel durability DONGKER 2 PCS CO2 1 Way Check Valves,CO2 Stainless Steel Non-Return Check Valve for CO2 Line 4/6mm Tubing Regulator Diffuser Aquarium CO2 Systems

**Brand:** dongker
**Price:** € 26.13
**Availability:** ✅ In Stock

## Summary

> 🔗 Lock in your aquarium’s CO2 flow—no backflow, no compromises!

## Quick Answers

- **What is this?** DONGKER 2 PCS CO2 1 Way Check Valves,CO2 Stainless Steel Non-Return Check Valve for CO2 Line 4/6mm Tubing Regulator Diffuser Aquarium CO2 Systems by dongker
- **How much does it cost?** € 26.13 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.nl](https://www.desertcart.nl/products/513280063-dongker-2-pcs-co2-1-way-check-valves-co2-stainless)

## Best For

- dongker enthusiasts

## Why This Product

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

## Key Features

- • **Effortless Installation:** Follow the arrow, snap it in, and enjoy hassle-free setup without leaks or guesswork.
- • **Zero Backflow Guarantee:** One-way valve design ensures water never reverses, protecting your aquarium’s delicate ecosystem.
- • **Trusted Aquarium Essential:** Join thousands of aquarists who rely on these valves to extend CO2 cylinder life and system efficiency.
- • **Precision Fit for CO2 Lines:** Optimized for standard 4mm inner and 6mm outer diameter tubing—seamless integration guaranteed.
- • **Built to Last with Stainless Steel:** Engineered for high pressure, acid, and alkali resistance to keep your CO2 system flawless.

## Overview

The DONGKER 2 PCS CO2 1 Way Check Valves are precision-engineered stainless steel valves designed exclusively for aquarium CO2 systems. They prevent water backflow, resist high pressure and corrosive environments, and fit standard 4/6mm tubing, ensuring optimal CO2 delivery and system longevity with easy installation.

## Description

welcome to my store , Hope you have a pleasant shopping trip! Features:1.Stainless steel material, high pressure resistance, acid and alkali It prevents backflow of water flow and maintains the functionality and longevity of the CO2 bottle. It also has anti-high pressure, anti-acid and alkali effect.2.only suit CO2 systems . Check valves are suitable for CO2 supply systems, not for air pumps. Suitable for pipes with an inner diameter of 4mm and an outer diameter of 6mm.Specifications Size: Suitable for pipes with an inner diameter of 4mm and an outer diameter of 6mm.Material:Stainless steel Package List:2PCS x 1 Way Check ValveNotes: 1. Due to the difference between different monitors, the picture may not reflect the actual color of the item. We the style is the same as shown in the pictures.2. Please allow 1-2cm slight dimension difference due to different manual measurement

Review: Check valves - Works well no issues
Review: Good and cheap - Works as it should

## Features

- Stainless Steel Material:High Pressure Resistance, Acid and Alkali Resistance Small and Exquisite, sturdy, 1-way Check Valve Can Prevent Water From Flowing Backwards
- High Performance: 1-way Air Valve to Prevent the Reverse Flow of the Water Plant Tank Due to the Reduction of CO2 Pressure, Which Will Affect the Function and Service Life of the Cylinder
- Installation Is Simple: just Follow the Direction Indicated By the Arrow to Connect With the Trachea,The Check Valve Can Ensure that the Water and Air Circulations Are Consistent and Going in the Right Direction Without Any Backflow
- For CO2 Systems Only: the Total Length Is About 4CM, Suitable for CO2 Supply Systems,suitable for Standard Aquarium CO2 Trachea (trachea Inner Diameter 4mm, Outer Diameter 6mm)
- SHOP WITH CONFIDENCE: To Provide You With the Highest Quality Service, If You Have Any Question, Please Contact Us.We Will Provide After-sales Service .

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B0B8HMTZL1 |
| Batteries Included | No |
| Batteries required | No |
| Best Sellers Rank | 47,050 in Pet Supplies ( See Top 100 in Pet Supplies ) 256 in Aquarium Air Pump Accessories |
| Customer Reviews | 4.1 4.1 out of 5 stars (28) |
| Date First Available | 3 Aug. 2022 |
| Item Weight | 100 g |
| Item model number | HM28712 |
| Product Dimensions | 2 x 2 x 2 cm; 100 g |
| Quantity | 1 |

## Images

![DONGKER 2 PCS CO2 1 Way Check Valves,CO2 Stainless Steel Non-Return Check Valve for CO2 Line 4/6mm Tubing Regulator Diffuser Aquarium CO2 Systems - Image 1](https://m.media-amazon.com/images/I/51KWzdYwEqL.jpg)

## Customer Reviews

### ⭐⭐⭐⭐⭐ Check valves
*by A***S on 16 November 2025*

Works well no issues

### ⭐⭐⭐⭐⭐ Good and cheap
*by M***Z on 26 October 2025*

Works as it should

### ⭐⭐ Not as described
*by G***F on 25 February 2025*

Terrible valves. Straight out the box they restrict the flow. You need to unscrew them and reverse the spring internal to use the valve. It will flow in the opposite direction to the flow arrows but works better. Very poor valve. See picture for correct way to fit

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**Shop now:** [https://www.desertcart.nl/products/513280063-dongker-2-pcs-co2-1-way-check-valves-co2-stainless](https://www.desertcart.nl/products/513280063-dongker-2-pcs-co2-1-way-check-valves-co2-stainless)

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*Product available on Desertcart Netherlands*
*Store origin: NL*
*Last updated: 2026-02-22*