Spec Blinds, spades/Spacers 1

[CM06]

Can anybody tell me the difference between a Class A and a Class B type of spacer. I need to order a 26", 150# spade for one of my jobs. Apparently I need to specifiy either A or B. Can any one shed some light onto this or show me where I may find the information I need.

 

[JLSeagull]

See Class 150 Series A and Series B flanges in ASME B16.47. These flanges have different dimensions.