Other sizes; 0.025" brass flat; Metric Brass Flats; 3/16" Brass Flats; 1/16" Brass Flats; 5/16" Brass Flats; . It does seem, however, that these adaptors are becoming less available; it's hard to find them on-line or at the major DIY stores, going to a 'proper' plumbers merchant probably gives the best chance for locating one. Buy imperial copper washers products and get the best deals at the lowest prices on eBay! Sold per metre, buy as much as you like up to 25 metres and we will send it in one continuous length (coiled). Please enable this in your browser settings. All tube is C106 grade so suitable for steam engines and silver soldering. 22, 28 and 35 mm - generally for long runs where use of 15 mm piping would cause excessive pressure drop. Trade outlets may only stock 3 and Please read AddThis Privacy for more information. Copper is relatively non-toxic - unlike lead. We pride ourselves as a reliable supplier of industrial pipe offering over 100 years of superior service. Advertisement #7 16-12-2020 10:52pm corkgsxr Registered Users Posts: 3,404 Join Date: October 2012 Posts: 3249 There is no Irish size. Registered in England and Wales 1 foot length of 42mm copper pipe / tube. General HDPE Sizing Chart | HDPE Pipe Specifications HDPE Pipes Dimension Charts with Different PSI Values Tap Connections. the body of the connector. fittings generally work on imperial 1/2" pipe. View All. Nominal width (DN) Dimension d x s (mm) Admissible pipe strength in accordance with EN 1173. Some connectors incorporate a solder ring within the body (as indicated by the ring formed in the connector as shown above) It will be labeled or written on the side or a valve. The information here is provided for guidance only. 21.5mm - This is used for overflows and is typically seen attached to water tanks in lofts and from cisterns. 35mm outside diameter, 1.2mm wall thickness, 32.6mm nominal inside diameter. needs of a pipe run. 14mm is normal for a kitchen (sink). to 22mm. Apart from the wall thickness, other pipe sizing parameters such as outer diameter of standard size pipes and NPS to DN conversion is also shown in the above tables. Trust Kelly to meet your needs and exceed your expectations while remaining competitive. 20.07 8.99. What size is imperial copper pipe? Free delivery on orders over 50 UK Mainland. 28mm outside diameter, 0.9mm wall thickness, 26.2mm nominal inside diameter. Buy Copper Pipe at Screwfix.ie. Definitions For example, 50mm pipe measures 50mm on the outer diameter. Buy Copper Pipe at Screwfix. in mm (inch.) At Plumb Parts our MDPE fittings are available in the following: Metric sizes 20mm, 25mm, 32mm. Copper Pipe Size Guide The actual outside diameter (OD) of copper pipe is always 1/8 inch larger than the nominal size. For example 1" imperial pressure pipe, when measured on its' outside diameter is exactly 48.3mm or just under 2". Cuts pipe from 3mm to 22mm, including the popular sizes 4mm, 5mm, 6mm, 8mm, 10mm, 12mm 15mm and 22mm. Flexible and easy to install. Weight. We don't stock imperial copper pipe (after 1972 the UK changed to metric), though we do have some information on its sizes. CH5 2UA, 01244 288000 FAX 01244 289000 NPS - 'Nominal Pipe Size' and DN - 'Diametre Nominal' - The size of pipes, fittings, flanges and valves are often given in inches as NPS - Nominal Pipe Size, or in metric units as DN - 'Diametre Nominal'. This also corresponds to the ISO denomination Cu-DHP. I have come across a Brittle Black plastic mains water pipe coming up from the floor in the cupboard next to the sink, connected to the mains stopcock, this pipe Is original from the 60/70s. JG Speedfit cold water service imperial converter push-fit fitting is used to a convert metric size MDPE fitting for use with imperial size LDPE to BS1972 Class C or Class D. Supplied with inch size pipe insert. When BSP pipe sizes changed to metric they did not change the bore size to an OD in metric but specified it as an approximate mm size of the nominal bore diameter. Please read Google Privacy & Terms for more information about how you can control adserving and the information collected. . In plumbing in Ireland and Britain (and other countries) the thread standard used is BSP or British Standard Pipe. Brake Lines & Fittings (158) Brake Lines. 6017: 1981. Copper pipe has good electrical conductivity and thermal conductivity, making it the primary material for conductive accessories and heat dissipation accessories of electronic products. Working pressures of metric sized copper tubes according the BS (British Standard) 2871. Great Savings & Free Delivery / Collection on many items . Type L is considered the most common type of copper pipe, as it can be used in many more applications than Type K. L copper is thinner than type K. Flexible L copper can be used to repair or replace old water lines, and also can be used outside the home where it will be directly exposed. The nominal bore is loosely related to the i/d of the pipe, there are different wall thicknesses or schedules available for each size, the o/d stays constant for each NB, the heavier the schedule of pipe the smaller the bore. The following are general descriptions of these four types: Type K copper pipe has the thickest wall of all the common types. Alternatively, if a pipe run is to be rearranged, the 22, 28 and 35 mm - generally for long runs where use of 15 mm piping would cause excessive pressure drop. Common sizes are 15 mm and 22 mm. Modern plumbing almost exclusively uses copper pipes for water feeds and central heating pipework although some modern plastic Metric Copper Coupling Reducers with Stop ( Pipe/Tubing OD ) Metric Copper 45 Degree Elbow ( Pipe/Tubing OD ) Metric Copper 45 Degree Street Elbow ( Fitting x Tubing/Pipe OD) Metric Copper 90 Degree Elbow ( Pipe/Tubing OD ) Metric Copper 90 Degree Street Elbow ( Fitting x Pipe/Tubing OD ) Metric Copper 90 Degree Long Turn Elbow ( Pipe/Tubing OD . point to bear in mind in the UK is that the measurement quoted for imperial sized pipe is the INNER diameter of the pipe whilst STD. It is true with all three common types of copper pipe, K, L, and M. The inside diameter (ID) of copper pipe is determined by the wall thickness of the pipe, which varies by the pipe type. This design tool completes all the hard stuff . Using our unique grip and seal push-fit technology, fittings firmly secure pipe and tubing in seconds without the need for tools, delivering installation and operational . For more info see, Stevenson Plumbing and Electrical Supplies, 5/8" x 1/2" x 3/4" Outside Tap Connector / Garden Hose Fitting Adaptor, Myson TRV 2 Way Replacement Thermostatic Valve Head Only, Washing Machine Appliance Waste Trap Blanking Cap with Washer, Franke Kitchen Sink Plug Rubber Seal / Washer No. Table 2: Wall Thickness Table for Standard Pipe Sizes from Schedule 100 to XXS. 0 The main styles are: Most of these are available either to accept the same sized pipes at each end or to accept different 8 and 10 mm - for use microbore central heating systems. 28 Nov 2010. 1/4 Compressed air connections3/8 Oil line connections, 1/2 Basin and Kitchen sink taps, radiator inlets, old outside tap outlets 5/8 Old outside tap outlets (very rare) 3/4 Bath taps, washing machine inlet hose connections, modern outside tap outlets 1 Domestic heating boilers 1.25 Wash hand basin wastes (bathroom sink) 1.5 Kitchen sink wastes (kitchen sink), bath wastes, WC siphon outlets2 Modern toilet flush valve outlets. Imperial copper tubes; Copper Square; STEEL Sections. UK 40mm waste is not the same size as French 40mm waste.. We can discuss this at the weekend if you like.. Like eurajohn-409239 14 years ago Pipe Fittings & Fastenings. Show Quoted Text . Showing 1-16 of 76 results. The three most common types of copper pipe used in residential and commercial construction are Type K, Type L, and Type M. A fourth type, used for drain-waste-vent, or DWV, piping, can be found in some older homes. Stability Copper pipe and tube does not creep with age and has 7 to 15 times less linear expansion than other materials with heat, and continues to perform at high temperatures. Nominal Pipe Size (abbreviated NPS) is a North American standard for identifying pipe sizes. A 50mm socket will measure 50mm on the Inner Diameter. 40mm - Used under kitchen sinks and also bathroom showers/baths. Great Savings & Free Delivery / Collection on many items . We don't collect information from our users. Delivery & Returns. Unfortunately for the average DIY enthusiast or anyone not very familiar with plumbing, pipe sizes in Ireland (and also the connections) can be confusing. Copper pipe for plumbing drains and vents was used in many old homes and commercial applications and has been all but replaced with PVC or ABS plastic pipe in modern construction. It is useful to know the size of your incoming pipes. View All. Copper pipe sizes, copper pipe fittings and tube is made to universal sizes, not a unique brand size. 15mm outside diameter, 0.7mm wall thickness, 13.6mm nominal inside diameter. Google use cookies for serving our ads and handling visitor statistics. Your email address will not be published. We cannot accept responsibility for you ordering the incorrect size for your needs. Not quite the metric 15mm, which is measured on the outside. Abbreviated S.W.G. An, Your email address will not be published. PEX pipes should be labeled every five feet with the information mentioned as follows: Pipe manufacturer's name or trademark Pipe standard - (ASTM F876, F877, AWWA C904 or CSA B137.5). Copper pipe from other countries (Republic of Ireland and America) are usually not the same as the UK sizes, due to different wall thickness. Tube Fittings (1804) Pipe & Tubing Accessories (710) Mini Barbed Fittings (26) Tubing & Tube . We keep a range of copper pipe in sizes from 4 mm to 54 mm. This white plastic coated 10mm copper pipe / tube is popular for central heating oil lines. Click to expand. cardi-538452 9 years ago. Copyright 2023 KnowSize.com All rights reserved. This is less. Click for PVC and ABS Pipe Click for See Copper Tube Click for Stainless Pipe The following is a quick conversion chart showing sizes of stainless steel, mild steel, plastic and copper tube or pipe. Insulation Thickness. Gatewarth Industrial Estate, Warrington, Cheshire, WA5 1DF 1/8 (3.175mm) copper tube available with wall thickness of 22 gauge / 22 SWG 0.027 (0.7mm) or 0.014 (0.36mm) in coils or straight lengths. JavaScript is required by this website. or hot air gun) and the small gap between the pipe and connector is filled with solder by capillary action. Lined Piping User Guide & Dimensions Steel Pipe Schedules and Dimensions The nominal bore is loosely related to the i/d of the pipe, there are different wall thicknesses or schedules available for each size, the o/d stays constant for each NB, the heavier the schedule of pipe the smaller the bore. Straight Copper pipe 600mm Wall Plate for outside Garden Bib Tap Only works for metric 35,32,28,22,15,12,10,8 mm pipes Steel pipes or imperial copper equivalent sizes could be used to give you a good idea, but will not be completely accurate. with BS10:62 Please contact 01254 237 409 for more information. Different pipe schedule means different wall thickness for the steel pipe in the same diameter. - - - - Call us on: 1800 946 602 Call us: 1800 946 602 Shop by Product Code Need Help. BSP thread size nominal names were originally based on the inner diameter (measured in inches) of the tube for which the thread was intended. Imperial Sizes; Metric Sizes; Pilotseal. If the thickness of the pipe is added on it comes to 21 mm which is not 22 mm. A threaded fitting can beMale(screwing into a female thread) orFemale(allowing a male thread to be screwed into it). This standard of measuring pipe came from a need to have a universal system for referring to PVC. Copper does not suffer corrosion - as iron does. SOLD IN 1FT LENGTHS ONLY - For example, if you buy a quantity of 2 you will get 2 separate 1 foot long pieces of pipe. We offer these inMetric(mm) andImperial(inch) sizes. In UK and internet you can buy 12x15 end feed connectors. White Label (Table Y), Tubes in coils to BS EN1057 So, the Irish pipe is 12.7mm bore, add on the thickness of the pipe & it comes to 14.7mm. DWV-grade: With a wall thickness of 0.42 in. Buy as much as you like up to 10 metres and we will send it all in one length (coiled). Nominal Pipe Sizes apply to all materials of pipe. 00252 S, 4 Different Radiator Bleed Keys Each With Its Own Advantage, Kitchen Sink P Trap With 2 Washing Machine Waste Pipe Spigot Connections, Ducting Backdraught Shutter / Flap 100mm (4"). Deeside Industrial Park, Flintshire. Threaded connectors are the same. The old British imperial copper pipe was described by the size in inches of its nominal bore, so the outside diameter is larger than the name of the size. Inch and metric systems (excepting 2 1/2" / 75 mm and 5" / 140 mm) are completely different sizes, and can only be joined together using adaptors or flanges with a common P.C.D.The following table indicates the approximate equivalent inch and metric sizes: Where applicable PVC fittings are according to ISO 727 and WRAS for potable water. Copper Tubing. A 50mm spigot fitting will measure 50mm on theouterdiameter. and for the waste pipes. The thread will 'bottom' and it will leak. Wednesbury Streamline plumbing tube is supplied in straight lengths in sizes ranging from 10mm up to 159mm diameter. For example, 50mm pipe measures 50mm on theouterdiameter. 42mm outside diameter, 1.2mm wall thickness, 39.6mm nominal inside diameter. I've never tried it with 16mm but I'd imagine it was similar. Road bicycles have their frames measured in centimetres, while off-road bicycles have their frames measured in . Our wastes are 1.25 for Basin Wastes and 1.5 for Kitchen Wastes.See here for details of our taps and waste collection. Depending on what fittings you are using, you can also get 22mm to 3/4 inch ring solder/endfeed converters. When measuring pipe we use the Outer diameter of the pipe, which will fit into a 'socket' fitting, which could be an elbow or a valve for example. STAINLESS STEEL 316 BSPT 2 PIECE LEVER BALL VALVE. Copper pipework in older installations will probably be sized in imperial measurements - 1/2 inch, 3/4 inch, 1 inch etc. For example, buy a quantity of 5 and receive one piece of 6mm pipe 5 metres long. posted 16 years ago. DWV pipe usually has yellow markings to distinguish it from M copper. Tue, Sep 19, 2006 6:15 PM. Answer (1 of 18): There are two types of lines that you need and you have to make sure that they're refrigerant grade they cannot be Plumbing grade so for suction lines you can have half inch 5/8 3/4 and on the liquid lines you can have 1/4 3/8 really there is no standard size you just have to fi. Copyright 2000 - 2023 diydata.com Reproduction of any content on this website is strictly forbidden. Wednesbury Tube is a wholly owned subsidiary of Mueller Industries Inc, Privacy Policy | Cookie Policy | Wednesbury Copper Tube. 10 mm outside diameter, 0.7mm wall thickness, 8.6mm nominal inside diameter. pipes are beginning to be used. People should always check with the local building authority for restrictions on its use. In the 1970s Britain changed from Imperial plumbing sizes to metric plumbing sizes. Imperial. Specification. ABS IMPERIAL CLASS 'E' PIPE x 5.8M - SIZES 1/2" TO 4" 33.82 to 545.73. See here for details of our taps and waste collection. No need to use calculations and tables to work out pipe sizes, it even tell you what size of gas meter should be fitted. Please select wall thickness and lengths from drop down boxes. Brake Line Accessories. . In fact these two sizes (1/2 inch and 15mm) can generally be joined using a 15 mm to 15mm connector. . The internal or external fluid pressure may determine the type of copper piping specified for any application, the installation, the service conditions, and the local building code requirements. The larger the table number, the thicker the . This is a Copper Pipe Sizes chart that gives you the approximate Inside dimension (ID) and wall thickness of copper pipes for 18 Nominal pipe sizes (NPS) including 3 types K, L, and M. NPS Outside Diameter (OD) Pipe Type Inside Diameter (ID) Wall Thickness; 1/4: 0.375: K: 0.305: 0.035: L: 0.315: 0.03: M: N/A: N/A: 3/8: 0.5: K: 0.402: 0.049: L . Engineering ToolBox - Resources, Tools and Basic Information for Engineering and Design of Technical Applications! Required fields are marked *. It is recommended for main water lines and underground installations because its thickness helps it withstand the pressure from backfilled earth. Pipe Sizing by Velocity. Dolphin Pool Cleaner Combination Gel Brush Set (4). And Imperial sizes from 1/2 " to 1 1/2 Our range of MDPE Fittings includes MDPE Connectors, MDPE Copper Couplers, MDPE Copper Liners, MDPE Copper Olives, MDPE Equal Elbows, MDPE Female Adaptors, JG SPEEDFIT MDPE IMPERIAL TO METRIC CONVERTERS, MDPE . 1/2" imperial pipe is 15.138 mm outside diameter 3/4" imperial pipe is 21.488 mm 1" imperial pipe is 28.245 mm The above is based on standard pipe sizes from BS659 (1944). Though the outside diameter of a schedule 80 pipe and a schedule 40 pipe are the same, 80 pipe has thicker walls. HDPE pipe must have a minimum density of 0.955 grams per cubic centimeter. Edit - on reflection, so far as I remember 1/2" copper water pipe was 1/2" bore, whereas the 15mm equivalent is 15mm OD 1/2" BSP is a thread size, used originally on 1/2" nominal bore iron or steel pipe. Shop in United Kingdom . In UK domestic plumbing the sizes commonly found are 8mm, 10mm, 15mm, 22mm, 28mm, 32mm, 40mm, 50mm, 68mm and 110mm; with sizes up to 28mm being used for hot and cold water supply, heating and gas supply, and larger sizes for waste, rainwater, soil and ventilation. repair as they cannot be disassembled. Connectors are also available to connect modern metric sized pipes These applications will - due to browser restrictions - send data between your browser and our server. For the best experience on our site, be sure to turn on Javascript in your browser. Our colleague Amira from the Engineering Team talks to Shini Somara at Engineering and Technology, Welded Fixed / Rotating Flanged Pipe Spool, Blanking Spades, Spectacle Blinds and Orifice Plates, Vent Bosses and Extensions For Lagged Lines, Companion Flanges for tight fit field flare spools, Installation, Operating and Maintenance Instructions, Pipe Fittings Dimensions ASME150 / 300 & DIN2484, Smoothbore Sleeves for use with Powder Duties, Atostar AS3 Full Bore Short Pattern Ball Valve, AKH3 Reduced Bore Short Pattern Ball Valve, Ball Valves with Extension / Locking Kits, ARV/SG Combined Check Valve and Bulls Eye Sight Glass, SPCV Integral Sight Glass / Wafer Poppet Check Valve, BFSG Integral Sight Glass / Floating Ball Check Valve, BTV2000 Type BTW Wafer Pattern Butterfly Valve, BTV2000 Long Pattern Wafer Style Butterfly Valve, BTV2000 Type BTL Lugged Style Butterfly Valve, Kammer Control Valve Pressure and Temperature chart, PFA lined Wafer Style Sampling Valve SD IL 400, Metallic Wafer Style Sampling Valve SD IL 300, Volumetric PFA lined Ductile Iron APN/SG, Metallic Flanged Sampling Valve SD IL TC, Trolley Mounted Recirculating Vessel Sampling System, High Temperature / Pressure Sampling System, PFA Lined Stainless Steel Tubular Sight Glass, ASG-4 4 Way (Cross) Bulls Eye Sight Glass, Managing Permeation in PTFE Lined Piping in Chlorine and HCL (NACE), Shell and Tube Silicon Carbide Heat Exchangers, Toughgask Reusable PTFE Encapsulated Stainless Steel Reinforced Gasket. For more info see, Stevenson Plumbing and Electrical Supplies, click here for information on the old pre 1972 sizes, White Plastic Coated 10mm Copper Pipe For Oil Per Metre, White Plastic Coated 10mm Copper Pipe (For Oil) 10m Coil, Yellow Plastic Coated 10mm Copper Pipe (For Gas) Per Metre, 5/8" x 1/2" x 3/4" Outside Tap Connector / Garden Hose Fitting Adaptor, Myson TRV 2 Way Replacement Thermostatic Valve Head Only, Washing Machine Appliance Waste Trap Blanking Cap with Washer, Franke Kitchen Sink Plug Rubber Seal / Washer No. Please see the diagram below for examples of the outer diameter of the various BSP threads: As you can see, 1/2 thread ( 1/2 = 12.7 mm) has a outside diameter of 20.995 mm. In summary: 2. 32mm - Found under small hand basins and other low volume outlets. 6mm copper pipe / microbore tube per metre. Copyright 2023 Swimfix Ltd. All Rights Reserved. Copper pipe is a type of non-ferrous metal pipe, which is a pressed and drawn seamless pipe. Metric copper pipe / tube dimensions are based on theoutside diameter of the pipe. It is easy to check the size of your pipes. R290 = Fully Hard, Temper Our pipe sizes shown here are for the Pressure Pipe we offer, and these can be different from standard domestic plumbing pipe from a hardware store. STAINLESS STEEL BSP TUBE, FITTINGS & VALVES , Stainless Steel BSP Valves. PEX pipes are manufactured and categorized by their outside diameter dimension, commonly called copper tube size (CTS). The sizes indicated in this system are the actual dimensions of the pipe or fittings. You can get a 'card' of olives from most Bricho's. Don't use the 15mm nut with a 14mm olive. Ed Sirett - Property maintainer and registered gas fitter. SOLD IN 1FT LENGTHS ONLY - For example, if you buy a quantity of 2 you will get 2 separate 1 foot long pieces of pipe. For our different markets, we supply the following size ranges: UK AND ASIA Tubes in straight lengths to BS EN1057 Black Label (Table X) Tubes in straight lengths to BS EN1057 Two basic types of connectors are used for joining copper pipes: 1. 54mm outside diameter, 1.2mm wall thickness, 51.6mm nominal inside diameter. - - - - Call 24/7 on: 03330 112 112 Call 24/7: 03330 112 112 Shop by Product Code Need Help. But it is not always allowed in all areas and applications due to thin wall. JavaScript seems to be disabled in your browser. Pilotseal Boiler Door Joints; Pilotseal Fitting Instructions; Topog-E. . Type M copper pipe is thinner than both type K and L copper pipe. UK Do-It-Yourself Forum; . It was constructed by improving the Birmingham wire gage. The Imperial sizes are based on the internal bore diameter of the pipe and the metric sizes are based on the external diameter of the pipe. GB 153 028 102, Lowara Ecocirc Variable Speed Heating Circulator Pumps, Lowara 5th Generation Hydrovar Inverter Variable Speed Drives, Hose - Hose Tails - Clips - Clamps - Valves, Tracpipe Flexible Gas Pipe Coil and BSP Fittings Pack, Tracpipe Flexible Gas Pipe Coil and Tape Pack, TracPipe Flexible GasPipe Coil & Compression Fittings Pack, Tracpipe Gas Pipe Straight Coupling Fittings, Tracpipe Installation Instructions & Info, Carbon Steel Welding Fittings Sched 40 BS1640, Flexible Tap Connectors Washing Machine Hoses and Valves, Polymax Streamline Push Fit Plumbing Fittings, Yorkshire XPress Copper Pipe and Fittings, Yorkshire Xpress Carbon Steel Press Fit Fittings, Yorkshire Xpress Stainless Steel Press Fit Fittings, Pegler Yorkshire Xpress Stainless Gas Fittings, Yorkshire Xpress Stainless Steel Tube SS610 and SS620, Yorkshire Xpress Press Fit Replacement O Rings, Pipe Hangers and Brackets Clips & Fixings, BZP Rubber Lined and Unlined Hangers & Brackets, Ball Gate Radiator Mixing Safety Regulating Check Drain Vent Float and Strainers, Albion Pressure Reducing Valve with Gauge, Spirax Sarco Steam and Condensate Traps and valves, Spirax Sarco Direct-acting Pressure Reducing BRV2s, Spirax Sarco Pressure Reducing Valve DP27, Spirax Sarco Air Vent AE30 and VB Vacuum Breaker, Spirax Sarco Self Acting Temperature Controls, Spirax Sarco Steel Baffle Type Separators, Plastic Ball Float and Fill Valves to BS1212 Parts 3 & 4, Wafer Pattern Stainless Steel Disc Check Valve, Cast Iron Balancing Double Regulating Valves, Pressure Vessels Switches and Ancillaries, Atlas Fileder Filters Housings and Cartridges, Ambersil Maintenance Repair and Overhaul Products, Jointing Compounds Tapes Sealant and Flux, Vulcathene 92.5 Degree Loose Nut Swept Bends, Conversions are based on a nominal 25mm or exact 25.4mm to 1 inch. Compared to this, the disadvantages of many other pipes are apparent. The following data will be used as a guide for information purposes only. Email: [email protected] Tel: 0161 408 2938 it is very slightly bigger than 15mm, so that fittings are hard to mount. For our different markets, we supply the following size ranges: Tubes in straight lengths to BS EN1057 We sell copper coil which is available in imperial sizes. JG SPEEDFIT MDPE IMPERIAL TO METRIC CONVERTER . Solder Connections Looking for Pipe, Tubing & Fittings? If more clarification and accuracy is required, you should refer to the relevant standard. If you've been shopping around for PVC for American-made items such as hot tubs, you may have heard the term schedule. NPS piping is defined in terms of a nominal diameter and wall thickness (defined by the pipe schedule). White 1 1-2" & 2" Pool Pipe System. Here we have both imperial and metric units. R220 = Soft Annealed Metric copper pipe / tube dimensions are based on the outside diameter of the pipe.