Butt Caps used as Heads Butt Caps used as Heads grumpiefool (Mechanical) (OP) 22 May 07 01:02 I want to use Butt caps for the heads of a 6" diameter tank. Which head type would one use in Compress for the calculation of a butt cap?Thanks in Advance. RE: Butt Caps used as Heads waskillywabbit (Mechanical) 23 May 07 17:35 I'm not familiar with the term "butt cap" but if you are talking about a "pipe cap" use a 2:1 elliptical with the appropriate length stratight flange. Brian RE: Butt Caps used as Heads doct9960 (Mechanical) 23 May 07 23:26 grumpiefool,I believe Compress does not do calculations for standard pipe fittings. You can model your pipe cap as a 2:1 SE head to graphically show it; but I would not rely on Compress' calculation output for that particular component.If your vessel code is ASME VIII-1 and your pipe cap is an ASME B16.9 fitting, refer to UG-44. RE: Butt Caps used as Heads dgrande (Mechanical) 30 May 07 09:47 I model pipe caps as 2:1 elliptical heads. You do have to keep in mind that the pipe caps have a 12-1/2% pipe tolerance though. RE: Butt Caps used as Heads eliebl (Mechanical) 5 Jun 07 11:08 Be very careful in your documentation of this calculation. Should an ASME team leader find a pipe cap calculated as an ellipsoidal head during a review you will get some grief. UG-44 is quite specific as to how it is calculated.