{"product_id":"raccord-union-inox-a-souder-316-pn20","title":"Stainless steel butt weld union 316, PN 20, weld ends both sides","description":"\u003cp\u003e\u003cstrong\u003eStainless steel butt weld union 316, PN 20\u003c\/strong\u003e, with plain butt weld (BW) ends on both sides, from Ø 13.5 to Ø 60.3 mm (sizes 1\/4\" to 2\", DN8 to DN50). It provides a point of disconnection on welded pipework. PN 20 up to 40 °C, drinking water compliant, for all fluids compatible with stainless steel.\u003c\/p\u003e\n\u003ch2\u003eDescription of the stainless steel butt weld union 316 PN 20\u003c\/h2\u003e\n\u003cp\u003eThis \u003cstrong\u003e3-piece stainless steel union\u003c\/strong\u003e consists of two weld ends and a nut. Both connections to the pipework are welded. Between the ends, the seal is metal to metal at the conical seat. Undoing the nut is enough to open the line, without cutting the pipe.\u003c\/p\u003e\n\u003cp\u003eThe whole union is investment cast (lost wax) in \u003cstrong\u003eCF8M (AISI 316)\u003c\/strong\u003e stainless steel, and designed, manufactured and inspected to ISO 4144. The ends have no flats; only the nut has them.\u003c\/p\u003e\n\u003cp\u003eAt your temperature, does the working pressure exceed the PN 20 limit? See the \u003ca href=\"\/products\/stainless-steel-butt-weld-union-316l-pn40\"\u003estainless steel butt weld union 316L PN 40\u003c\/a\u003e, from Ø 21.3 to Ø 60.3 mm, which has no high-temperature figures: for hot applications, \u003ca href=\"\/pages\/contact\"\u003econtact us\u003c\/a\u003e before choosing. Does one side need to screw on? Choose the \u003ca href=\"\/products\/stainless-steel-union-female-butt-weld-316-pn20\"\u003estainless steel female\/butt weld union PN 20\u003c\/a\u003e or the \u003ca href=\"\/products\/stainless-steel-union-male-butt-weld-316-pn20\"\u003estainless steel male\/butt weld union PN 20\u003c\/a\u003e.\u003c\/p\u003e\n\u003ch3\u003eStainless steel butt weld union: technical specifications\u003c\/h3\u003e\n\u003cdiv style=\"overflow-x:auto;-webkit-overflow-scrolling:touch;margin:.8em 0\"\u003e\u003ctable style=\"width:100%;border-collapse:collapse;font-size:.92rem;margin:0\"\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd style=\"border:1px solid #ddd;padding:8px 12px;font-weight:700;text-align:left;background:#f5f0e6;white-space:nowrap\"\u003eMaterial\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:8px 12px;text-align:left\"\u003eCF8M (AISI 316) stainless steel\u003c\/td\u003e\u003c\/tr\u003e\u003ctr\u003e\u003ctd style=\"border:1px solid #ddd;padding:8px 12px;font-weight:700;text-align:left;background:#f5f0e6;white-space:nowrap\"\u003eManufacture\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:8px 12px;text-align:left\"\u003eInvestment casting (lost wax)\u003c\/td\u003e\u003c\/tr\u003e\u003ctr\u003e\u003ctd style=\"border:1px solid #ddd;padding:8px 12px;font-weight:700;text-align:left;background:#f5f0e6;white-space:nowrap\"\u003eStandard\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:8px 12px;text-align:left\"\u003eDesigned, manufactured and inspected to ISO 4144\u003c\/td\u003e\u003c\/tr\u003e\u003ctr\u003e\u003ctd style=\"border:1px solid #ddd;padding:8px 12px;font-weight:700;text-align:left;background:#f5f0e6;white-space:nowrap\"\u003eType\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:8px 12px;text-align:left\"\u003eConical (taper) seat union, 3-piece: two weld ends and a nut\u003c\/td\u003e\u003c\/tr\u003e\u003ctr\u003e\u003ctd style=\"border:1px solid #ddd;padding:8px 12px;font-weight:700;text-align:left;background:#f5f0e6;white-space:nowrap\"\u003eSeal at the seat\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:8px 12px;text-align:left\"\u003eMetal to metal\u003c\/td\u003e\u003c\/tr\u003e\u003ctr\u003e\u003ctd style=\"border:1px solid #ddd;padding:8px 12px;font-weight:700;text-align:left;background:#f5f0e6;white-space:nowrap\"\u003eShape\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:8px 12px;text-align:left\"\u003ePlain ends without flats, nut with flats\u003c\/td\u003e\u003c\/tr\u003e\u003ctr\u003e\u003ctd style=\"border:1px solid #ddd;padding:8px 12px;font-weight:700;text-align:left;background:#f5f0e6;white-space:nowrap\"\u003eConnection\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:8px 12px;text-align:left\"\u003eButt weld (BW) at both ends; Ø = outside diameter of the end\u003c\/td\u003e\u003c\/tr\u003e\u003ctr\u003e\u003ctd style=\"border:1px solid #ddd;padding:8px 12px;font-weight:700;text-align:left;background:#f5f0e6;white-space:nowrap\"\u003eEnds\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:8px 12px;text-align:left\"\u003e2 weld ends\u003c\/td\u003e\u003c\/tr\u003e\u003ctr\u003e\u003ctd style=\"border:1px solid #ddd;padding:8px 12px;font-weight:700;text-align:left;background:#f5f0e6;white-space:nowrap\"\u003eNominal pressure\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:8px 12px;text-align:left\"\u003ePN 20: 20 bar from −20 to 40 °C, lower above that\u003c\/td\u003e\u003c\/tr\u003e\u003ctr\u003e\u003ctd style=\"border:1px solid #ddd;padding:8px 12px;font-weight:700;text-align:left;background:#f5f0e6;white-space:nowrap\"\u003eTemperature\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:8px 12px;text-align:left\"\u003e−20\/+220 °C, permissible pressure reduced above 40 °C\u003c\/td\u003e\u003c\/tr\u003e\u003ctr\u003e\u003ctd style=\"border:1px solid #ddd;padding:8px 12px;font-weight:700;text-align:left;background:#f5f0e6;white-space:nowrap\"\u003eFluids\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:8px 12px;text-align:left\"\u003eAll fluids compatible with stainless steel\u003c\/td\u003e\u003c\/tr\u003e\u003ctr\u003e\u003ctd style=\"border:1px solid #ddd;padding:8px 12px;font-weight:700;text-align:left;background:#f5f0e6;white-space:nowrap\"\u003eSizes\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:8px 12px;text-align:left\"\u003e8 sizes, from Ø 13.5 to Ø 60.3 mm (1\/4\" to 2\")\u003c\/td\u003e\u003c\/tr\u003e\u003ctr\u003e\u003ctd style=\"border:1px solid #ddd;padding:8px 12px;font-weight:700;text-align:left;background:#f5f0e6;white-space:nowrap\"\u003eCompliance\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:8px 12px;text-align:left\"\u003e4MS; drinking water: French order of 25 June 2020\u003c\/td\u003e\u003c\/tr\u003e\u003c\/tbody\u003e\u003c\/table\u003e\u003c\/div\u003e\n\u003ch3\u003ePressure and temperature\u003c\/h3\u003e\n\u003cp\u003ePN 20 applies from −20 to 40 °C. Above that, the permissible pressure falls. Values marked ≈ are read from the pressure\/temperature curve in the technical data sheet.\u003c\/p\u003e\n\u003cdiv style=\"overflow-x:auto;-webkit-overflow-scrolling:touch;margin:.8em 0\"\u003e\u003ctable style=\"width:100%;border-collapse:collapse;font-size:.88rem;margin:0\"\u003e\u003cthead\u003e\u003ctr\u003e\u003cth style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap;background:#f5f0e6;font-weight:700\"\u003eTemperature (°C)\u003c\/th\u003e\u003cth style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap;background:#f5f0e6;font-weight:700\"\u003eMax. pressure (bar)\u003c\/th\u003e\u003c\/tr\u003e\u003c\/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e−20 → 40\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e20\u003c\/td\u003e\u003c\/tr\u003e\u003ctr style=\"background:#fafafa\"\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e100\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e≈ 16.5\u003c\/td\u003e\u003c\/tr\u003e\u003ctr\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e150\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e≈ 15\u003c\/td\u003e\u003c\/tr\u003e\u003ctr style=\"background:#fafafa\"\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e220\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e≈ 13.5\u003c\/td\u003e\u003c\/tr\u003e\u003c\/tbody\u003e\u003c\/table\u003e\u003c\/div\u003e\n\u003ch3\u003eCertification and compliance\u003c\/h3\u003e\u003cp\u003eAccording to the technical data sheet for the series:\u003c\/p\u003e\u003cul\u003e\u003cli\u003e\u003cstrong\u003e4MS\u003c\/strong\u003e: compliant with the 4MS requirements, the harmonized European rules for materials and products in contact with drinking water.\u003c\/li\u003e\u003cli\u003e\u003cstrong\u003eDrinking water\u003c\/strong\u003e: compliant with the French order (arrêté) of 25 June 2020 on metallic materials and products in contact with water intended for human consumption.\u003c\/li\u003e\u003c\/ul\u003e\n\u003ch3\u003eUses and installation advice\u003c\/h3\u003e\n\u003cp\u003eThis union goes on welded pipework, wherever part of the line must be removable, on drinking water systems and on circuits carrying fluids compatible with 316 stainless steel. Check fluid compatibility and the permissible pressure at the working temperature.\u003c\/p\u003e\n\u003cul\u003e\u003cli\u003e\u003cstrong\u003eWelding\u003c\/strong\u003e: to be carried out by a qualified welder. The welding process and filler metal depend on the installation.\u003c\/li\u003e\u003cli\u003e\u003cstrong\u003eBefore welding\u003c\/strong\u003e: dismantle the union and separate the ends to protect the conical seat. Keep the seat clean at every reassembly.\u003c\/li\u003e\u003cli\u003e\u003cstrong\u003eGalling\u003c\/strong\u003e: with stainless steel on stainless steel, the nut can gall. Screw it on gradually, without forcing.\u003c\/li\u003e\u003cli\u003e\u003cstrong\u003eTightening\u003c\/strong\u003e: tighten the nut with an open-ended or adjustable spanner, not with pipe grips or pliers, which mark stainless steel. As the ends have no flats, hold them with a strap wrench.\u003c\/li\u003e\u003c\/ul\u003e\n\u003ch3\u003eTechnical drawing\u003c\/h3\u003e\n\u003cfigure style=\"margin:1.2em 0;text-align:center;padding:0\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/2439\/6099\/files\/dessin-technique-raccord-union-inox-a-souder-pn20.png\" alt=\"Technical drawing of the stainless steel butt weld union PN 20, dimensions A, B and Ø\" loading=\"lazy\" decoding=\"async\" width=\"1939\" height=\"1619\" fetchpriority=\"low\" style=\"max-width:100%;height:auto;display:block;margin:0 auto;border:1px solid #eee;border-radius:4px;background:#fff\"\u003e\u003cfigcaption style=\"font-size:.85rem;color:#666;margin-top:.4em;font-style:italic\"\u003eDimensioned drawing – dimensions in millimetres\u003c\/figcaption\u003e\u003c\/figure\u003e\n\u003ch3\u003eDimensions (mm)\u003c\/h3\u003e\n\u003cp\u003eA: overall length. Ø: outside diameter of the weld ends. B: outside dimension of the nut. Dimensions in millimetres, PN in bar, weight in kilograms.\u003c\/p\u003e\n\u003cdiv style=\"overflow-x:auto;-webkit-overflow-scrolling:touch;margin:.8em 0\"\u003e\u003ctable style=\"width:100%;border-collapse:collapse;font-size:.88rem;margin:0\"\u003e\u003cthead\u003e\u003ctr\u003e\u003cth style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap;background:#f5f0e6;font-weight:700\"\u003eSize\u003c\/th\u003e\u003cth style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap;background:#f5f0e6;font-weight:700\"\u003eFrench size\u003c\/th\u003e\u003cth style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap;background:#f5f0e6;font-weight:700\"\u003eØ\u003c\/th\u003e\u003cth style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap;background:#f5f0e6;font-weight:700\"\u003eA\u003c\/th\u003e\u003cth style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap;background:#f5f0e6;font-weight:700\"\u003eB\u003c\/th\u003e\u003cth style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap;background:#f5f0e6;font-weight:700\"\u003ePN (bar)\u003c\/th\u003e\u003cth style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap;background:#f5f0e6;font-weight:700\"\u003eWeight (kg)\u003c\/th\u003e\u003c\/tr\u003e\u003c\/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e1\/4\"\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e8x13\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e13.5\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e31.5\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e33\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e20\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e0.069\u003c\/td\u003e\u003c\/tr\u003e\u003ctr style=\"background:#fafafa\"\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e3\/8\"\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e12x17\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e17.2\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e38\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e37\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e20\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e0.110\u003c\/td\u003e\u003c\/tr\u003e\u003ctr\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e1\/2\"\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e15x21\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e21.3\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e40.5\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e40\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e20\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e0.135\u003c\/td\u003e\u003c\/tr\u003e\u003ctr style=\"background:#fafafa\"\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e3\/4\"\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e20x27\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e26.9\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e46\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e49.5\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e20\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e0.195\u003c\/td\u003e\u003c\/tr\u003e\u003ctr\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e1\"\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e26x34\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e33.7\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e49\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e56\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e20\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e0.250\u003c\/td\u003e\u003c\/tr\u003e\u003ctr style=\"background:#fafafa\"\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e1\"1\/4\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e33x42\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e42.4\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e54\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e67\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e20\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e0.380\u003c\/td\u003e\u003c\/tr\u003e\u003ctr\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e1\"1\/2\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e40x49\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e48.3\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e56\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e73\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e20\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e0.442\u003c\/td\u003e\u003c\/tr\u003e\u003ctr style=\"background:#fafafa\"\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e2\"\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e50x60\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e60.3\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e64\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e90\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e20\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e0.739\u003c\/td\u003e\u003c\/tr\u003e\u003c\/tbody\u003e\u003c\/table\u003e\u003c\/div\u003e\n\u003ch3\u003eSize conversion\u003c\/h3\u003e\n\u003cp\u003eConversion between the French size designation, inches, DN and the outside diameter stated in the designation (a rounded value, not a pipe dimension). The actual diameter of the end is dimension Ø.\u003c\/p\u003e\n\u003cdiv style=\"overflow-x:auto;-webkit-overflow-scrolling:touch;margin:.8em 0\"\u003e\u003ctable style=\"width:100%;border-collapse:collapse;font-size:.88rem;margin:0\"\u003e\u003cthead\u003e\u003ctr\u003e\u003cth style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap;background:#f5f0e6;font-weight:700\"\u003eFrench size\u003c\/th\u003e\u003cth style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap;background:#f5f0e6;font-weight:700\"\u003e8x13\u003c\/th\u003e\u003cth style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap;background:#f5f0e6;font-weight:700\"\u003e12x17\u003c\/th\u003e\u003cth style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap;background:#f5f0e6;font-weight:700\"\u003e15x21\u003c\/th\u003e\u003cth style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap;background:#f5f0e6;font-weight:700\"\u003e20x27\u003c\/th\u003e\u003cth style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap;background:#f5f0e6;font-weight:700\"\u003e26x34\u003c\/th\u003e\u003cth style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap;background:#f5f0e6;font-weight:700\"\u003e33x42\u003c\/th\u003e\u003cth style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap;background:#f5f0e6;font-weight:700\"\u003e40x49\u003c\/th\u003e\u003cth style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap;background:#f5f0e6;font-weight:700\"\u003e50x60\u003c\/th\u003e\u003c\/tr\u003e\u003c\/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap;font-weight:700\"\u003eInches\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e1\/4\"\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e3\/8\"\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e1\/2\"\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e3\/4\"\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e1\"\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e1\"1\/4\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e1\"1\/2\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e2\"\u003c\/td\u003e\u003c\/tr\u003e\u003ctr style=\"background:#fafafa\"\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap;font-weight:700\"\u003eDN\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003eDN8\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003eDN10\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003eDN15\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003eDN20\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003eDN25\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003eDN32\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003eDN40\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003eDN50\u003c\/td\u003e\u003c\/tr\u003e\u003ctr\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap;font-weight:700\"\u003eOD (French size)\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e13 mm\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e17 mm\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e21 mm\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e27 mm\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e34 mm\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e42 mm\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e49 mm\u003c\/td\u003e\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;text-align:center;white-space:nowrap\"\u003e60 mm\u003c\/td\u003e\u003c\/tr\u003e\u003c\/tbody\u003e\u003c\/table\u003e\u003c\/div\u003e\n\u003ch3\u003eStainless steel butt weld union: frequently asked questions\u003c\/h3\u003e\n\u003ch4\u003eWhy a union rather than a direct weld?\u003c\/h4\u003e\u003cp\u003eThe nut opens the joint without cutting the pipework. The seal is then restored by metal-to-metal contact at the conical seat.\u003c\/p\u003e\n\u003ch4\u003eHow do I read the diameter?\u003c\/h4\u003e\u003cp\u003eThe size option gives the outside diameter of the end, followed by the size designation in inches: Ø 21.3 mm (1\/2\"). Approving the weld on your pipe is a matter for your welder.\u003c\/p\u003e\n\u003ch4\u003eWhat is the pressure rating at 100 °C?\u003c\/h4\u003e\u003cp\u003e≈ 16.5 bar, against 20 bar from −20 to 40 °C.\u003c\/p\u003e\n\u003cp\u003e\u003cem\u003eThe appearance of the part may vary depending on the batch in stock. \u003ca href=\"\/pages\/contact\"\u003eContact us\u003c\/a\u003e for confirmation.\u003c\/em\u003e\u003c\/p\u003e\n\u003ch3\u003eSee also\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eFull range:\u003c\/strong\u003e \u003ca href=\"\/collections\/stainless-steel-bsp-pipe-fittings\"\u003eall stainless steel BSP fittings\u003c\/a\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eOther stainless steel fittings:\u003c\/strong\u003e \u003ca href=\"\/products\/stainless-steel-union-female-female-316-pn20\"\u003estainless steel female\/female union PN 20\u003c\/a\u003e or \u003ca href=\"\/products\/stainless-steel-union-male-female-316-pn20\"\u003estainless steel male\/female union PN 20\u003c\/a\u003e for a screwed joint at both ends.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eOther materials:\u003c\/strong\u003e \u003ca href=\"\/collections\/brass-fittings\"\u003ebrass fittings\u003c\/a\u003e, \u003ca href=\"\/collections\/black-unions\"\u003eblack malleable iron unions\u003c\/a\u003e.\u003c\/p\u003e\n","brand":"Home Invasion","offers":[{"title":"Ø 13.5 mm (1\/4\")","offer_id":55701967995207,"sku":"8008500000800","price":16.0,"currency_code":"USD","in_stock":true},{"title":"Ø 17.2 mm (3\/8\")","offer_id":55701968027975,"sku":"8008500001200","price":19.0,"currency_code":"USD","in_stock":true},{"title":"Ø 21.3 mm (1\/2\")","offer_id":55701968060743,"sku":"8008500001500","price":21.0,"currency_code":"USD","in_stock":true},{"title":"Ø 26.9 mm (3\/4\")","offer_id":55701968093511,"sku":"8008500002000","price":30.0,"currency_code":"USD","in_stock":true},{"title":"Ø 33.7 mm (1\")","offer_id":55701968126279,"sku":"8008500002600","price":35.0,"currency_code":"USD","in_stock":true},{"title":"Ø 42.4 mm (1\"1\/4)","offer_id":55701968159047,"sku":"8008500003300","price":54.0,"currency_code":"USD","in_stock":true},{"title":"Ø 48.3 mm (1\"1\/2)","offer_id":55701968191815,"sku":"8008500004000","price":65.0,"currency_code":"USD","in_stock":true},{"title":"Ø 60.3 mm (2\")","offer_id":55701968224583,"sku":"8008500005000","price":103.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/2439\/6099\/files\/raccord-union-inox-a-souder-316-pn20-1.jpg?v=1793802716","url":"https:\/\/home-invasion.com\/products\/stainless-steel-butt-weld-union-316-pn20","provider":"Home Invasion","version":"1.0","type":"link"}