This type of auxiliary accessories within fluid control systems perform various functions such as directing fluids (elbows), pressure change (reductions), shunt (tees), flanged coupling (stub ends), are joined by butt welding , for which they have the characteristic of having a bevel, through it, the welding achieves a good penetration and mechanical resistance.
Butt weldable connections are manufactured under the guidelines of the ASTM standard (American Society for Testing and Materials) and of which we can find them with designation of grade WP and CR.
In the connections WP grade (Wrought Products), products of conformation of its translation into Spanish, its dimensions are governed by the standard ASME (American Society of Mechanical Engineers) B16.9 to be used in high pressure and temperature systems.
While the CR grade (Corrosion resistant) connections, have the dimensions of the guidelines of the MSS-SP43 (Standardization Society for Valve and Connection Manufacturers) to withstand 30% of the working pressure of the control systems of fluids and temperatures not greater than 450 ° C.
Both grades can be manufactured from tubes with or without welding.