{"product_id":"upvc-non-return-flap-check-valve-pipe-fittings","title":"UPVC One Way Non Return Flap Check Valve Pipe Fittings I.D 20 25 32 40 50 63mm","description":"\u003cdiv class=\"hdiy-desc\"\u003e\n\u003cdiv class=\"hdiy-overview\"\u003e\n\u003ch2\u003eUPVC Non Return Flap Check Valve — Stop Backflow in Plastic Pipe Systems\u003c\/h2\u003e\n\u003cp\u003eBackflow contamination and reverse-flow damage are persistent headaches for irrigation installers, pool plumbers, and drainage engineers working with plastic pipe systems. The UPVC one-way non return flap check valve is engineered to solve exactly that — allowing flow in one direction only, automatically closing the moment pressure reverses.\u003c\/p\u003e\n\u003cp\u003eEach valve is machined from rigid unplasticized PVC (UPVC), offering excellent resistance to chlorine, mild acids, and common irrigation chemicals. The internal flap mechanism seats firmly under reverse pressure without requiring springs or external actuators. Available in six inner-diameter sizes — 20mm (≈0.79\"), 25mm (≈0.98\"), 32mm (≈1.26\"), 40mm (≈1.57\"), 50mm (≈1.97\"), and 63mm (≈2.48\") — to match standard metric PVC pipe schedules.\u003c\/p\u003e\n\u003cp\u003eTypical applications include residential and commercial drip irrigation backflow prevention, swimming pool and spa return-line protection, rainwater harvesting tank inlet control, and gravity-fed drainage systems where reverse siphoning must be blocked. The lightweight UPVC body makes it a practical choice for above-ground and in-wall installations where metal valves would add unnecessary load.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"hdiy-compat\"\u003e\n\u003cspan class=\"hdiy-compat-icon\"\u003e🔗\u003c\/span\u003e Compatible with standard metric UPVC\/PVC pressure pipe in I.D sizes 20, 25, 32, 40, 50, and 63mm. Suitable for cold water, irrigation fluids, and mild chemical solutions within rated pressure limits. Not recommended for hot water lines above 60°C (140°F).\u003c\/div\u003e\n\u003cdiv class=\"hdiy-features\"\u003e\n\u003ch2\u003e✅ Key Features of These UPVC Non Return Flap Check Valves\u003c\/h2\u003e\n\u003cul class=\"hdiy-list\"\u003e\n\u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e🔄\u003c\/span\u003e\u003cstrong\u003eOne-Way Flap Mechanism\u003c\/strong\u003e — The internal flap opens freely under forward flow and seals automatically when pressure reverses, preventing backflow without manual intervention.\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e🧪\u003c\/span\u003e\u003cstrong\u003eChemical-Resistant UPVC Body\u003c\/strong\u003e — Rigid unplasticized PVC resists chlorine, fertilizer solutions, mild acids, and UV exposure, making these UPVC check valves suitable for outdoor irrigation and pool plumbing.\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e📐\u003c\/span\u003e\u003cstrong\u003eSix Size Options\u003c\/strong\u003e — Available in I.D 20, 25, 32, 40, 50, and 63mm to match the most common metric PVC pipe schedules used in residential and light commercial systems.\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e⚖️\u003c\/span\u003e\u003cstrong\u003eLightweight Construction\u003c\/strong\u003e — The UPVC body is significantly lighter than brass or cast-iron check valves, reducing stress on pipe joints and simplifying overhead or in-wall installation.\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e🔧\u003c\/span\u003e\u003cstrong\u003eTool-Free Flap Operation\u003c\/strong\u003e — No springs, solenoids, or external actuators required. The gravity-assisted flap resets automatically, minimizing maintenance requirements over the valve's service life.\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e💧\u003c\/span\u003e\u003cstrong\u003eLow Cracking Pressure\u003c\/strong\u003e — The flap design opens at low differential pressure, ensuring minimal flow restriction in gravity-fed and low-pressure irrigation systems.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"hdiy-table-wrap\"\u003e\n\u003ch2\u003e📐 Technical Specifications — UPVC Flap Check Valve\u003c\/h2\u003e\n\u003ctable\u003e\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eMaterial\u003c\/th\u003e\n\u003ctd\u003eUPVC (Unplasticized PVC)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eValve Type\u003c\/th\u003e\n\u003ctd\u003eOne-Way Non Return Flap Check Valve\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eAvailable Inner Diameters\u003c\/th\u003e\n\u003ctd\u003e20mm \/ 25mm \/ 32mm \/ 40mm \/ 50mm \/ 63mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eConnection Type\u003c\/th\u003e\n\u003ctd\u003eSolvent weld socket (slip fit)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eMax Working Pressure\u003c\/th\u003e\n\u003ctd\u003eSee variant options\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eWorking Temperature Range\u003c\/th\u003e\n\u003ctd\u003e0°C – 60°C (32°F – 140°F)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eFluid Compatibility\u003c\/th\u003e\n\u003ctd\u003eCold water, irrigation solutions, mild chemicals\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eActuation\u003c\/th\u003e\n\u003ctd\u003eGravity \/ differential pressure (no external actuator)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eColor\u003c\/th\u003e\n\u003ctd\u003eGrey\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eQuantity per Order\u003c\/th\u003e\n\u003ctd\u003e1 piece\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\u003c\/table\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"hdiy-faq\"\u003e\n\u003ch2\u003e❓ Frequently Asked Questions\u003c\/h2\u003e\n\u003cdetails\u003e\u003csummary\u003eWhich size UPVC check valve do I need for my pipe?\u003c\/summary\u003e\u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eMatch the valve's inner diameter (I.D) to your existing pipe's inner diameter. Common metric PVC pipe sizes are 20mm, 25mm, 32mm, 40mm, 50mm, and 63mm. If you are unsure, measure the inside bore of your pipe or check the pipe's printed specification. Using a valve one size too small will restrict flow; one size too large will not seal correctly.\u003c\/p\u003e\u003c\/div\u003e\u003c\/details\u003e\u003cdetails\u003e\u003csummary\u003eCan this valve handle irrigation fertilizer or chemical solutions?\u003c\/summary\u003e\u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eYes. UPVC is resistant to a wide range of fertilizer solutions, mild acids, and chlorinated water commonly used in drip and sprinkler irrigation. Always verify chemical compatibility for concentrated or aggressive solutions before installation.\u003c\/p\u003e\u003c\/div\u003e\u003c\/details\u003e\u003cdetails\u003e\u003csummary\u003eIs this check valve suitable for hot water systems?\u003c\/summary\u003e\u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eNo. This valve is rated for cold water and ambient-temperature fluid applications up to approximately 60°C (140°F). For hot water or steam lines, a metal-bodied check valve rated for higher temperatures is required.\u003c\/p\u003e\u003c\/div\u003e\u003c\/details\u003e\u003cdetails\u003e\u003csummary\u003eHow is the valve installed — does it need solvent cement?\u003c\/summary\u003e\u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eThe valve uses a standard solvent weld (slip) socket connection. Apply UPVC solvent cement to the pipe end and the valve socket, push together with a quarter-turn, and hold for 30 seconds. Allow full cure time per the cement manufacturer's instructions before pressurizing the line.\u003c\/p\u003e\u003c\/div\u003e\u003c\/details\u003e\u003cdetails\u003e\u003csummary\u003eWill the flap seal completely under reverse pressure?\u003c\/summary\u003e\u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eUnder normal operating conditions the gravity-assisted flap seats firmly against the valve body when reverse pressure is applied, providing a reliable one-way seal. For applications requiring zero-leakage shut-off under sustained high back-pressure, a spring-loaded or dual-plate check valve may be more appropriate.\u003c\/p\u003e\u003c\/div\u003e\u003c\/details\u003e\u003cdetails\u003e\u003csummary\u003eHow do I choose between a flap check valve and a spring check valve?\u003c\/summary\u003e\u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eFlap check valves rely on gravity and differential pressure to close, making them ideal for horizontal or slightly inclined pipe runs with moderate flow velocities. Spring check valves close faster and work in any orientation, including vertical downward flow. For low-pressure gravity irrigation and drainage, the flap type is typically sufficient and offers lower flow resistance.\u003c\/p\u003e\u003c\/div\u003e\u003c\/details\u003e\u003cdetails\u003e\u003csummary\u003eCan I use this valve on a swimming pool return line?\u003c\/summary\u003e\u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eYes. UPVC flap check valves are commonly used on pool and spa return lines to prevent back-siphoning when the pump is off. Ensure the selected I.D matches your return pipe bore and that the valve is installed with flow direction aligned to the arrow or flap orientation marked on the body.\u003c\/p\u003e\u003c\/div\u003e\u003c\/details\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"hdiy-cta\"\u003e\u003cp\u003e🛒 Select your size and quantity above, then add to cart.\u003c\/p\u003e\u003c\/div\u003e\n\u003c\/div\u003e\u003cscript type=\"application\/ld+json\"\u003e{\"@context\":\"https:\/\/schema.org\",\"@type\":\"FAQPage\",\"mainEntity\":[{\"@type\":\"Question\",\"name\":\"Which size UPVC check valve do I need for my pipe?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Match the valve inner diameter (I.D) to your existing pipe inner diameter. Common metric PVC pipe sizes are 20mm, 25mm, 32mm, 40mm, 50mm, and 63mm. Measure the inside bore of your pipe or check the pipe printed specification.\"}},{\"@type\":\"Question\",\"name\":\"Can this valve handle irrigation fertilizer or chemical solutions?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Yes. UPVC is resistant to fertilizer solutions, mild acids, and chlorinated water commonly used in drip and sprinkler irrigation. Verify chemical compatibility for concentrated solutions before installation.\"}},{\"@type\":\"Question\",\"name\":\"Is this check valve suitable for hot water systems?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"No. This valve is rated for cold water and ambient-temperature fluid applications up to approximately 60 degrees Celsius. For hot water or steam lines, a metal-bodied check valve is required.\"}},{\"@type\":\"Question\",\"name\":\"How is the valve installed — does it need solvent cement?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"The valve uses a standard solvent weld socket connection. Apply UPVC solvent cement to the pipe end and valve socket, push together with a quarter-turn, and hold for 30 seconds. Allow full cure time before pressurizing.\"}},{\"@type\":\"Question\",\"name\":\"Will the flap seal completely under reverse pressure?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Under normal operating conditions the gravity-assisted flap seats firmly against the valve body when reverse pressure is applied. For zero-leakage shut-off under sustained high back-pressure, a spring-loaded check valve may be more appropriate.\"}},{\"@type\":\"Question\",\"name\":\"How do I choose between a flap check valve and a spring check valve?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Flap check valves rely on gravity and differential pressure to close, ideal for horizontal pipe runs with moderate flow. Spring check valves close faster and work in any orientation. For low-pressure gravity irrigation, the flap type offers lower flow resistance.\"}},{\"@type\":\"Question\",\"name\":\"Can I use this valve on a swimming pool return line?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Yes. UPVC flap check valves are commonly used on pool and spa return lines to prevent back-siphoning when the pump is off. Ensure the selected I.D matches your return pipe bore and flow direction is correctly aligned.\"}}]}\u003c\/script\u003e","brand":"HomeDIYer","offers":[{"title":"20mm \/ 1Pcs","offer_id":52332178440466,"sku":"PENG020530x1","price":13.67,"currency_code":"USD","in_stock":true},{"title":"25mm \/ 1Pcs","offer_id":52332178473234,"sku":"PENG020531x1","price":14.67,"currency_code":"USD","in_stock":true},{"title":"32mm \/ 1Pcs","offer_id":52332178506002,"sku":"PENG020532x1","price":22.24,"currency_code":"USD","in_stock":true},{"title":"40mm \/ 1Pcs","offer_id":52332178538770,"sku":"PENG020533x1","price":26.04,"currency_code":"USD","in_stock":true},{"title":"50mm \/ 1Pcs","offer_id":52332178571538,"sku":"PENG020534x1","price":31.95,"currency_code":"USD","in_stock":true},{"title":"63mm \/ 1Pcs","offer_id":52332178604306,"sku":"PENG020535x1","price":41.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0884\/8936\/1682\/files\/Picture1of8_10002e63-2a63-4954-9268-d3ebbb5ab5b2.jpg?v=1782193009","url":"https:\/\/homediyer.com\/products\/upvc-non-return-flap-check-valve-pipe-fittings","provider":"HomeDIYer","version":"1.0","type":"link"}