{"product_id":"back-draught-shutter-bds-1","title":"Back-Draught Shutter (BDS)","description":"\u003cp data-start=\"167\" data-end=\"611\"\u003eThe \u003cstrong data-start=\"190\" data-end=\"220\"\u003eBack-Draught Shutter (BDS)\u003c\/strong\u003e is a mechanical device installed in ductwork to prevent reverse airflow when a fan or ventilation system is not operating. It automatically closes when air pressure drops, stopping unwanted drafts, heat loss, or ingress of dust and contaminants. Back-draught shutters are commonly used in HVAC supply, extract, and exhaust systems for commercial, industrial, and residential applications.\u003c\/p\u003e\n\u003cp data-start=\"613\" data-end=\"628\"\u003e\u003cstrong data-start=\"613\" data-end=\"626\"\u003eMaterial:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul data-start=\"629\" data-end=\"940\"\u003e\n\u003cli data-section-id=\"1g19ys\" data-start=\"629\" data-end=\"720\"\u003e\n\u003cp data-start=\"631\" data-end=\"720\"\u003e\u003cstrong data-start=\"631\" data-end=\"642\"\u003eCasing:\u003c\/strong\u003e Galvanised steel or stainless steel for durability and corrosion resistance\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-section-id=\"zdy6dg\" data-start=\"721\" data-end=\"789\"\u003e\n\u003cp data-start=\"723\" data-end=\"789\"\u003e\u003cstrong data-start=\"723\" data-end=\"734\"\u003eBlades:\u003c\/strong\u003e Aluminium or steel, lightweight for smooth operation\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-section-id=\"yvz4hv\" data-start=\"790\" data-end=\"875\"\u003e\n\u003cp data-start=\"792\" data-end=\"875\"\u003e\u003cstrong data-start=\"792\" data-end=\"810\"\u003eHinges\/Shafts:\u003c\/strong\u003e Stainless steel or zinc-plated steel for long-lasting movement\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-section-id=\"mt2mlm\" data-start=\"876\" data-end=\"940\"\u003e\n\u003cp data-start=\"878\" data-end=\"940\"\u003e\u003cstrong data-start=\"878\" data-end=\"899\"\u003eSeals (optional):\u003c\/strong\u003e Rubber or silicone to minimise leakage\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"942\" data-end=\"963\"\u003e\u003cstrong data-start=\"942\" data-end=\"961\"\u003eSpecifications:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul data-start=\"964\" data-end=\"1621\"\u003e\n\u003cli data-section-id=\"30ak50\" data-start=\"964\" data-end=\"1034\"\u003e\n\u003cp data-start=\"966\" data-end=\"1034\"\u003e\u003cstrong data-start=\"966\" data-end=\"975\"\u003eType:\u003c\/strong\u003e Gravity-operated or spring-assisted back-draught shutter\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-section-id=\"wjkt2d\" data-start=\"1035\" data-end=\"1119\"\u003e\n\u003cp data-start=\"1037\" data-end=\"1119\"\u003e\u003cstrong data-start=\"1037\" data-end=\"1047\"\u003eSizes:\u003c\/strong\u003e Available in circular and rectangular ducts, custom sizes as required\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-section-id=\"z8hr8d\" data-start=\"1120\" data-end=\"1193\"\u003e\n\u003cp data-start=\"1122\" data-end=\"1193\"\u003e\u003cstrong data-start=\"1122\" data-end=\"1142\"\u003ePressure Rating:\u003c\/strong\u003e Suitable for low to medium pressure duct systems\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-section-id=\"hxftg\" data-start=\"1194\" data-end=\"1260\"\u003e\n\u003cp data-start=\"1196\" data-end=\"1260\"\u003e\u003cstrong data-start=\"1196\" data-end=\"1209\"\u003eMounting:\u003c\/strong\u003e Inline duct installation, wall, or roof openings\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-section-id=\"c2dqz8\" data-start=\"1261\" data-end=\"1358\"\u003e\n\u003cp data-start=\"1263\" data-end=\"1358\"\u003e\u003cstrong data-start=\"1263\" data-end=\"1283\"\u003eBlade Operation:\u003c\/strong\u003e Opens under positive airflow and closes automatically under reverse flow\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-section-id=\"1g654g\" data-start=\"1359\" data-end=\"1444\"\u003e\n\u003cp data-start=\"1361\" data-end=\"1444\"\u003e\u003cstrong data-start=\"1361\" data-end=\"1372\"\u003eFinish:\u003c\/strong\u003e Galvanised steel standard; powder coating or stainless steel optional\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-section-id=\"jcwea8\" data-start=\"1445\" data-end=\"1529\"\u003e\n\u003cp data-start=\"1447\" data-end=\"1529\"\u003e\u003cstrong data-start=\"1447\" data-end=\"1464\"\u003eApplications:\u003c\/strong\u003e Supply, extract, and exhaust air systems in HVAC installations\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-section-id=\"rnaqg2\" data-start=\"1530\" data-end=\"1621\"\u003e\n\u003cp data-start=\"1532\" data-end=\"1621\"\u003e\u003cstrong data-start=\"1532\" data-end=\"1554\"\u003eOptional Features:\u003c\/strong\u003e Motorised actuation, locking mechanism, and weatherproof option\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Direct Duct Supplies","offers":[{"title":"100mm","offer_id":57219752395077,"sku":null,"price":6.2,"currency_code":"GBP","in_stock":true},{"title":"125mm","offer_id":57219752427845,"sku":null,"price":8.0,"currency_code":"GBP","in_stock":true},{"title":"150mm","offer_id":57219752460613,"sku":null,"price":9.1,"currency_code":"GBP","in_stock":true},{"title":"200mm","offer_id":57219752493381,"sku":null,"price":12.6,"currency_code":"GBP","in_stock":true},{"title":"250mm","offer_id":57219752526149,"sku":null,"price":21.1,"currency_code":"GBP","in_stock":true},{"title":"315mm","offer_id":57219752558917,"sku":null,"price":29.1,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1037\/5168\/0325\/files\/bds_0f07b349-9644-4e44-baaa-505f8692cc36.jpg?v=1771760340","url":"https:\/\/directductsupplies.com\/products\/back-draught-shutter-bds-1","provider":"Direct Duct Supplies","version":"1.0","type":"link"}