{"product_id":"champion-big-lock-straight-union-coupling","title":"Champion Big-Lock Straight Union Coupling - Standard and High Temperature (73mm to 220mm)","description":"\u003cp\u003eThe grooved coupling is the whole idea of \u003cstrong\u003eChampion Big-Lock\u003c\/strong\u003e. Two halves wrap a pair of grooved pipe ends, a gasket seals on the outside diameter, two bolts pull it together, and a 6 in aluminum main is joined in a couple of minutes by two people with a wrench. No welding, no flanges to line up, no threading, no hot work permit.\u003c\/p\u003e\u003cp\u003eThis listing is the \u003cstrong\u003estraight union coupling\u003c\/strong\u003e that joins two lengths of Big-Lock tube in line, 73mm through 220mm, with a \u003cstrong\u003estandard\u003c\/strong\u003e or \u003cstrong\u003ehigh temperature\u003c\/strong\u003e seal.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eChoose your size and seal from the dropdowns above.\u003c\/strong\u003e\u003c\/p\u003e\u003ch2\u003eModel Selection Chart\u003c\/h2\u003e\u003ctable\u003e\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003ePart Number\u003c\/th\u003e\n\u003cth\u003eSize\u003c\/th\u003e\n\u003cth\u003eNominal\u003c\/th\u003e\n\u003cth\u003eSeal\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eXCBL-SC-73S\u003c\/td\u003e\n\u003ctd\u003e73mm\u003c\/td\u003e\n\u003ctd\u003e2-1\/2 in\u003c\/td\u003e\n\u003ctd\u003eStandard\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eXCBL-SC-90S\u003c\/td\u003e\n\u003ctd\u003e90mm\u003c\/td\u003e\n\u003ctd\u003e3 in\u003c\/td\u003e\n\u003ctd\u003eStandard\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eXCBL-SC-115S\u003c\/td\u003e\n\u003ctd\u003e115mm\u003c\/td\u003e\n\u003ctd\u003e4 in\u003c\/td\u003e\n\u003ctd\u003eStandard\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eXCBL-SC-168S\u003c\/td\u003e\n\u003ctd\u003e168mm\u003c\/td\u003e\n\u003ctd\u003e6 in\u003c\/td\u003e\n\u003ctd\u003eStandard\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eXCBL-SC-220S\u003c\/td\u003e\n\u003ctd\u003e220mm\u003c\/td\u003e\n\u003ctd\u003e8 in\u003c\/td\u003e\n\u003ctd\u003eStandard\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eXCBL-SC-73H\u003c\/td\u003e\n\u003ctd\u003e73mm\u003c\/td\u003e\n\u003ctd\u003e2-1\/2 in\u003c\/td\u003e\n\u003ctd\u003eHigh temperature\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eXCBL-SC-90H\u003c\/td\u003e\n\u003ctd\u003e90mm\u003c\/td\u003e\n\u003ctd\u003e3 in\u003c\/td\u003e\n\u003ctd\u003eHigh temperature\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eXCBL-SC-115H\u003c\/td\u003e\n\u003ctd\u003e115mm\u003c\/td\u003e\n\u003ctd\u003e4 in\u003c\/td\u003e\n\u003ctd\u003eHigh temperature\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eXCBL-SC-168H\u003c\/td\u003e\n\u003ctd\u003e168mm\u003c\/td\u003e\n\u003ctd\u003e6 in\u003c\/td\u003e\n\u003ctd\u003eHigh temperature\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eXCBL-SC-220H\u003c\/td\u003e\n\u003ctd\u003e220mm\u003c\/td\u003e\n\u003ctd\u003e8 in\u003c\/td\u003e\n\u003ctd\u003eHigh temperature\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\u003c\/table\u003e\u003cp\u003eChampion catalogs a \u003cstrong\u003e273mm (10 in)\u003c\/strong\u003e Big-Lock range as well, but the current price list prints the 273mm couplings and most 273mm fittings as consult factory. Call or email and we will quote them.\u003c\/p\u003e\u003ch2\u003eHow Many Couplings Does the Job Need?\u003c\/h2\u003e\u003cp\u003eMore than people expect, and this is the line most commonly short on a take-off.\u003c\/p\u003e\u003cp\u003eEvery joint between two sticks of tube is one coupling. Big-Lock tube comes in \u003cstrong\u003e16 ft lengths\u003c\/strong\u003e, so a 200 ft main is roughly twelve couplings before you have added a single fitting. On top of that, the Big-Lock elbows, tees and reduction tees in this range are supplied \u003cstrong\u003ewith their couplings included\u003c\/strong\u003e, so those do not need separate ones, but the reducers are supplied \u003cstrong\u003ewithout\u003c\/strong\u003e couplings and need two each.\u003c\/p\u003e\u003cp\u003eSend us the layout and we will count them properly. Running out of couplings at hour six of an install is an expensive way to learn this.\u003c\/p\u003e\u003ch2\u003eStandard or High Temperature Seal?\u003c\/h2\u003e\u003cp\u003eThe \u003cstrong\u003estandard\u003c\/strong\u003e seal covers normal compressed air service and is what the overwhelming majority of systems use. The \u003cstrong\u003ehigh temperature\u003c\/strong\u003e seal is for runs close to a compressor discharge or an aftercooler, hot plant environments, or where heat and lubricant carryover together are hard on the standard compound.\u003c\/p\u003e\u003cp\u003eOne honest caveat. Champion's current price list does not publish a temperature rating, a pressure rating or a dimensional table for the Big-Lock range, and we have not found a Big-Lock datasheet that does. We are not going to print numbers we cannot source. \u003cstrong\u003eIf your application is near a temperature or pressure limit, call us and we will get the figures from the factory before you order\u003c\/strong\u003e, which matters here because these are no-return items.\u003c\/p\u003e\u003ch2\u003eShared Technical Specifications\u003c\/h2\u003e\u003ctable\u003e\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eSpecification\u003c\/th\u003e\n\u003cth\u003eValue\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSystem\u003c\/td\u003e\n\u003ctd\u003eChampion Big-Lock grooved mechanical coupling for aluminum pipe\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePipe Material\u003c\/td\u003e\n\u003ctd\u003eMarine-grade aluminum, non-corrosive, one-tenth the weight of the same diameter steel\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eJoint Type\u003c\/td\u003e\n\u003ctd\u003eTwo-piece grooved coupling, bolted, sealing on the tube outside diameter\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSizes\u003c\/td\u003e\n\u003ctd\u003e73mm (2-1\/2 in) through 220mm (8 in); 273mm (10 in) by quote\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSeal Options\u003c\/td\u003e\n\u003ctd\u003eStandard or high temperature\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eInstallation\u003c\/td\u003e\n\u003ctd\u003eNo welding, gluing or threading. The pipe is grooved on site with the Champion grooving tool\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWarranty\u003c\/td\u003e\n\u003ctd\u003eChampion Lifetime Warranty on Quick-Lock and Big-Lock pipe and fittings\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\u003c\/table\u003e\u003cp\u003e\u003cstrong\u003eSpecification note.\u003c\/strong\u003e The price list publishes description, part number and list price for the Big-Lock range and nothing else: no pressure rating, no temperature band, no weights and no dimensions. Everything stated above comes from Champion's own published Big-Lock material. Ask us for anything further and we will source it from the factory rather than estimate it.\u003c\/p\u003e\u003ch2\u003eIdeal Applications\u003c\/h2\u003e\u003cp\u003ePlant mains and loop headers above 2-1\/2 in, compressor room manifolds, replacing a corroded steel or black iron header without hot work in an operating building, and any run where the flow has outgrown Quick-Lock's 63mm top end. Common in large manufacturing, food and beverage, automotive assembly, and anywhere a shutdown to weld pipe is not acceptable.\u003c\/p\u003e\u003ch2\u003eBig-Lock and Quick-Lock Together\u003c\/h2\u003e\u003cp\u003eThe normal architecture is a \u003cstrong\u003eBig-Lock main loop with Quick-Lock branches\u003c\/strong\u003e. Big-Lock carries the volume around the building; Quick-Lock takes it from the loop down to the bays and the machines, where its push-fit fittings are far quicker to work with.\u003c\/p\u003e\u003cp\u003eOne warning worth repeating. \u003cstrong\u003e73mm Big-Lock and 63mm Quick-Lock are both called 2-1\/2 in nominal and they are not interchangeable.\u003c\/strong\u003e Different outside diameters, different joint systems. Order by the metric size and the system name, never by the inch nominal alone.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\u003ca href=\"https:\/\/aircompressorstore.com\/products\/champion-big-lock-series-aluminum-compressed-air-pipe\"\u003eBig-Lock aluminum pipe, 73mm to 273mm\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/aircompressorstore.com\/products\/champion-big-lock-union-elbow\"\u003eBig-Lock 90 and 45 degree elbows and street elbows\u003c\/a\u003e, supplied with couplings\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/aircompressorstore.com\/products\/champion-big-lock-union-tee\"\u003eBig-Lock junction tees and reduction tees\u003c\/a\u003e, supplied with couplings\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/aircompressorstore.com\/products\/champion-big-lock-adapter-and-reducer\"\u003eBig-Lock threaded adapters and reducers\u003c\/a\u003e - note reducers need couplings ordered separately\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"https:\/\/aircompressorstore.com\/products\/champion-big-lock-plug-cap\"\u003eBig-Lock plug caps\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/aircompressorstore.com\/products\/champion-quick-lock-series-aluminum-compressed-air-pipe\"\u003eQuick-Lock aluminum pipe, 14mm to 63mm\u003c\/a\u003e for the branches\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eOrdering Notes\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eAll Big-Lock products and accessories are NO CANCEL \/ NO RETURN.\u003c\/strong\u003e Champion states this in capitals at the top of every Big-Lock page. Confirm sizes and counts before the order goes in; we are happy to check the take-off with you first.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFreight:\u003c\/strong\u003e all Big-Lock shipments are freight collect from Huntersville, NC 28078 or Las Vegas, NV 89113.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eShipping weights:\u003c\/strong\u003e Champion publishes no weight for any Big-Lock fitting, so no catalog weight is carried on these variants. Large grooved couplings are heavy; we quote freight on the complete package.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eWhy Buy from Air Compressor Store\u003c\/h2\u003e\u003cp\u003eAir Compressor Store is an authorized Champion Pneumatic distributor. Big-Lock is a system you plan once and live with for twenty years, so send us the floor plan before you buy anything. Our compressed air engineers will size the main, decide where Big-Lock should hand over to Quick-Lock, count the couplings and fittings properly and quote the whole package at no charge.\u003c\/p\u003e\u003ch2\u003eFrequently Asked Questions\u003c\/h2\u003e\u003ch3\u003eDo I need to groove the pipe myself?\u003c\/h3\u003e\u003cp\u003eYes. Big-Lock tube is supplied plain-ended and the groove is rolled on site with the Champion manual grooving tool, which we also supply. That is what lets you cut a run to length in the building rather than ordering made-to-measure pipe. Budget for the tool on the first Big-Lock job; it is reusable forever after.\u003c\/p\u003e\u003ch3\u003eIs the coupling reusable?\u003c\/h3\u003e\u003cp\u003eThe coupling hardware is, which is one of the real advantages of a grooved system over welding. Undo the bolts, pull the halves apart, move the pipe, reassemble. Inspect the gasket and replace it if it is nicked or hardened; replacement seals are catalogued separately in the Big-Lock range.\u003c\/p\u003e\u003ch3\u003eWhy is the 220mm high temperature coupling so much more than the 168mm?\u003c\/h3\u003e\u003cp\u003e$1,467 against $482 at list, which is what Champion's August 2026 price list publishes. The high temperature seal premium grows sharply with size across the whole Big-Lock range. Both are shown here at Champion's list price rather than smoothed.\u003c\/p\u003e\u003ch3\u003eCan I join Big-Lock straight to steel pipe?\u003c\/h3\u003e\u003cp\u003eNot with this coupling, which is tube to tube. Use a \u003ca href=\"https:\/\/aircompressorstore.com\/products\/champion-big-lock-adapter-and-reducer\"\u003eBig-Lock threaded adapter\u003c\/a\u003e to land on an NPT thread, or a Big-Lock flange kit to bolt to a flanged connection. Both are in the Big-Lock range and we can quote them with the couplings.\u003c\/p\u003e\u003ch3\u003eWhat pressure will Big-Lock hold?\u003c\/h3\u003e\u003cp\u003eChampion does not publish a pressure rating for the Big-Lock range in the current price list and we have not found one in a Big-Lock datasheet, so we will not quote you a figure. For comparison, Champion does publish 220 PSIG for Quick-Lock. If your system pressure is anywhere near the top of normal shop air, ask us and we will confirm with the factory in writing before you order.\u003c\/p\u003e\u003ch3\u003eDo elbows and tees come with couplings?\u003c\/h3\u003e\u003cp\u003eYes, the Big-Lock elbows, junction tees and reduction tees are all catalogued with couplings included. The \u003cstrong\u003ereducers are not\u003c\/strong\u003e and need two couplings each. That single difference accounts for most short orders on this range.\u003c\/p\u003e","brand":"Champion","offers":[{"title":"73mm \/ 2.5 in \/ Standard","offer_id":67579382137107,"sku":"XCBL-SC-73S","price":78.57,"currency_code":"USD","in_stock":true},{"title":"90mm \/ 3 in \/ Standard","offer_id":67579382169875,"sku":"XCBL-SC-90S","price":91.53,"currency_code":"USD","in_stock":true},{"title":"115mm \/ 4 in \/ Standard","offer_id":67579382202643,"sku":"XCBL-SC-115S","price":123.93,"currency_code":"USD","in_stock":true},{"title":"168mm \/ 6 in \/ Standard","offer_id":67579382235411,"sku":"XCBL-SC-168S","price":195.21,"currency_code":"USD","in_stock":true},{"title":"220mm \/ 8 in \/ Standard","offer_id":67579382268179,"sku":"XCBL-SC-220S","price":328.05,"currency_code":"USD","in_stock":true},{"title":"73mm \/ 2.5 in \/ High Temperature","offer_id":67579382300947,"sku":"XCBL-SC-73H","price":158.76,"currency_code":"USD","in_stock":true},{"title":"90mm \/ 3 in \/ High Temperature","offer_id":67579382333715,"sku":"XCBL-SC-90H","price":170.1,"currency_code":"USD","in_stock":true},{"title":"115mm \/ 4 in \/ High Temperature","offer_id":67579382366483,"sku":"XCBL-SC-115H","price":262.44,"currency_code":"USD","in_stock":true},{"title":"168mm \/ 6 in \/ High Temperature","offer_id":67579382399251,"sku":"XCBL-SC-168H","price":390.42,"currency_code":"USD","in_stock":true},{"title":"220mm \/ 8 in \/ High Temperature","offer_id":67579382432019,"sku":"XCBL-SC-220H","price":1188.27,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0825\/3141\/8387\/files\/Big-Lock-Union.jpg?v=1790983951","url":"https:\/\/aircompressorstore.com\/products\/champion-big-lock-straight-union-coupling","provider":"Warthog Air Compressor Store","version":"1.0","type":"link"}