--- product_id: 55288887 title: "MF3 Rat Barrier- Non Return Valve (DRAINS) 4\" Clay or Plastic Pipe" brand: "multi-flap" price: "$195.42" currency: USD in_stock: true reviews_count: 8 category: "Multi Flap" url: https://www.desertcart.ec/products/55288887-mf3-rat-barrier-non-return-valve-drains-4-clay-plastic store_origin: EC region: Ecuador --- # Simple, tool-free installation Stops rat ingress effectively One-way non-return valve MF3 Rat Barrier- Non Return Valve (DRAINS) 4" Clay or Plastic Pipe **Brand:** multi-flap **Price:** $195.42 **Availability:** βœ… In Stock ## Summary > 🚫 Seal out rats, open up peace of mind! ## Quick Answers - **What is this?** MF3 Rat Barrier- Non Return Valve (DRAINS) 4" Clay or Plastic Pipe by multi-flap - **How much does it cost?** $195.42 with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.ec](https://www.desertcart.ec/products/55288887-mf3-rat-barrier-non-return-valve-drains-4-clay-plastic) ## Best For - multi-flap enthusiasts ## Why This Product - Trusted multi-flap brand quality - Free international shipping included - Worldwide delivery with tracking - 15-day hassle-free returns ## Key Features - β€’ **Smart One-Way Valve:** Allows waste to exit while instantly sealing to prevent backflow and pest entry. - β€’ **Effortless Installation:** Fits seamlessly into 4-inch plastic or clay pipesβ€”no plumbing pro needed. - β€’ **Rat-Proof Drain Defense:** Keep your home rat-free with a reliable barrier that blocks vermin at the source. - β€’ **Peace of Mind Protection:** Reduce pest activity and protect your property with a proven, easy-to-maintain solution. - β€’ **Durable High-Grade Plastic:** Engineered for longevity and resistance, balancing cost and performance. ## Overview The MF3 Rat Barrier Non-Return Valve is a 4-inch lift check valve designed for plastic or salt-glazed clay pipes. It installs easily in inspection chambers to prevent rats from entering drainage systems by allowing waste to flow out while closing immediately after to block backflow. Made from high-grade plastic with a stainless steel spring, it offers a cost-effective, durable solution to vermin intrusion in home drainage, ideal for professional-grade pest control and plumbing maintenance. ## Description THIS UNIT IS FOR 4 INCH (100mm) PLASTIC OR SALT GLAZED/CLAY PIPEWORK. Please not this unit is NOT suitable for an outlet pipe into manhole, it will only be suitable for the pipe that exits manhole to sewer, therefore you need to locate last chamber before sewer. How does it work? This unit fits into the chanel exit in an inspection chamber to stop back flow or rats entering your drainage system. The MultiFlap is a one-way non-return valve that fits easily to the exit pipe from your house to the street sewer. This means waste still goes out from your house, but immediately after the waste water has gone, the flap closes to prevent anything nasty coming up the wrong way. The prevention method and the ease with which the MultiFlap can be installed makes these products truly unique. How can vermin get into my drains? Since the 1950's drainage systems have been much less isolated from the main street sewer and this has allowed rats more access into peoples drainage systems. Damaged or unmaintained storm drains and sewer pipes easily allow vermin access into the main drainage systems. From here they can enter your home by travelling through sewers, up pipes and exiting from the foul air outlet at roof level or swimming through the water contained in your toilet system. The MultiFlap ensures you’re protected by keeping them in the sewers where the authorities can deal with them. Brilliant new device to stop rats gaining access into your drainage system. Please note; this model is made of a high grade plastic, but a determined rat can, and will, chew through plastic. Although this is very rare, it is possible. If this this concerns you, you might like to consider a more expensive stainless steel model. Review: Great value product. - Bought these a couple of years ago. Easy to fit and no problems with them at all. A lot less expensive than metal ones and seem to last. Review: The door is sprung with just the right amount of tension to close tight once waste or water has passed through - For ease of fitting it's a 5 star product, once I had chipped away a small section of benching in the sewer it slotted in and worked perfectly. The door is sprung with just the right amount of tension to close tight once waste or water has passed through, which it does without issue. Time will tell if the filthy, horrible things are getting in via the drains but already activity seems to of dropped off meaning there may just be the odd one that needs to leave and shut the door on the way out. Providing the door spring is stainless steel and they don't chew through the plastic/polyprop door itself it appears well made and should last. ## Features - Stops Rats entering - Simple to fit - Non-Return valve ## Technical Specifications | Specification | Value | |---------------|-------| | ASIN | B00PLN1UPA | | Best Sellers Rank | 60,522 in Garden ( See Top 100 in Garden ) 6,767 in Pest Control Products | | Brand | Multi-Flap | | Connector Type | Sweat, Socket Weld | | Customer Reviews | 3.6 out of 5 stars 107 Reviews | | Exterior Finish | Plastic | | Exterior finish | Plastic | | Inlet Connection Size | 4 Inches | | Inlet Connection Type | Socket Weld | | Inlet connection size | 4 Inches | | Inlet connection type | Socket Weld | | Manufacturer | Multi-Flap | | Material | Plastic, Stainless Steel | | Model Number | MF3 | | Number of Ports | 1 | | Outlet Connection Size | 4 Inches | | Outlet Connection Type | Sweat | | Outlet connection type | Sweat | | Part Number | MF3 | | Set Name | Rat Barrier | | Size | 4 inches | | Thread Size | 4 inches | | Thread Type | Non-threaded | | UPC | 609788764618 | | Unit Count | 1.0 count | | Valve Type | Lift Check Valve | ## Product Details - **Brand:** Multi-Flap - **Exterior finish:** Plastic - **Inlet connection size:** 4 Inches - **Inlet connection type:** Socket Weld - **Material:** Plastic, Stainless Steel - **Number of Packs:** 1 - **Number of ports:** 1 - **Outlet connection size:** 4 Inches - **Outlet connection type:** Sweat - **Unit count:** 1.0 count ## Images ![MF3 Rat Barrier- Non Return Valve (DRAINS) 4" Clay or Plastic Pipe - Image 1](https://m.media-amazon.com/images/I/31QHytiNs2L.jpg) ![MF3 Rat Barrier- Non Return Valve (DRAINS) 4" Clay or Plastic Pipe - Image 2](https://m.media-amazon.com/images/I/81tONVZuU5L.jpg) ## Questions & Answers **Q: Does it also stop odours ?** A: Sounds like you installed it the wrong way round, as the pressure to dislodge it, should have poured thru the gate, not against the gate **Q: Is there a possibility that the flap can stick/stay open over time (i,e. Spring/hinge failure)?** A: There are always possibilities with these things but after selling them for past 8 years we have not had it happen... **Q: is the valve open easily when flushing, would spring reduce the flushing flow or cause any blocking or partial blocking?** A: I have 2 fitted in my main drain and have not experienced any blockage problemsThe flap lifts when water goes through on light water flow also opens up when a toilet is flushed allowing paper and other particles to flow throughBoth valves have been fitted now for 5months **Q: Hi, my clay sewer coming out of my kitchen has a diameter of about 95mm. Does this product would work with this kind of sewer? Thanks** A: Yes it should work for you, check your measurements as it is designed to fit a 4'' or 100mm pipe. Ensure that the trap sits square in the drain and you tack it down with silicone. Test that the door swings open. Better to clean out the area before you start. ## Customer Reviews ### ⭐⭐⭐⭐⭐ Great value product. *by B***K on 12 June 2020* Bought these a couple of years ago. Easy to fit and no problems with them at all. A lot less expensive than metal ones and seem to last. ### ⭐⭐⭐⭐ The door is sprung with just the right amount of tension to close tight once waste or water has passed through *by D***N on 2 February 2016* For ease of fitting it's a 5 star product, once I had chipped away a small section of benching in the sewer it slotted in and worked perfectly. The door is sprung with just the right amount of tension to close tight once waste or water has passed through, which it does without issue. Time will tell if the filthy, horrible things are getting in via the drains but already activity seems to of dropped off meaning there may just be the odd one that needs to leave and shut the door on the way out. Providing the door spring is stainless steel and they don't chew through the plastic/polyprop door itself it appears well made and should last. ### ⭐ Broke whilst being fitted! So useless and a waste of money for a bit of plastic!!!! *by P***M on 12 July 2023* My husband attempted to fit following the instructions but the flap broke whilst he was putting the valve into the pipe. Totally useless and clearly was either faulty or just not fit for purpose. To top it all, I cannot return the item as it has been down the sewer!!! I am very unhappy about wasting Β£25 on a piece of plastic that has not served its purpose and am certainly not wasting another Β£25. ## Frequently Bought Together - Multi-Flap MF3 Rat Barrier- Non Return Valve (DRAINS) 4" Clay or Plastic pipe - Roshield Rat Drain Guard | Stop Rats within Drainage & Properties | Rodent Flap Control & Prevention Proofing (Stainless Steel 4"/110mm) - Retro Fit 110mm 4 inch Drain Non Return Valve with Stainless Steel Flap --- ## Why Shop on Desertcart? - πŸ›’ **Trusted by 1.3+ Million Shoppers** β€” Serving international shoppers since 2016 - 🌍 **Shop Globally** β€” Access 737+ million products across 21 categories - πŸ’° **No Hidden Fees** β€” All customs, duties, and taxes included in the price - πŸ”„ **15-Day Free Returns** β€” Hassle-free returns (30 days for PRO members) - πŸ”’ **Secure Payments** β€” Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** β€” Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.ec/products/55288887-mf3-rat-barrier-non-return-valve-drains-4-clay-plastic](https://www.desertcart.ec/products/55288887-mf3-rat-barrier-non-return-valve-drains-4-clay-plastic) --- *Product available on Desertcart Ecuador* *Store origin: EC* *Last updated: 2026-07-04*