The tubes shall be manufactured from steel strip by electric welding. The tubes shall not included welds used for joining of flat rolled strip prior to forming the tube, except for coiled tubes which may be supplied in the delivery conditions +A and +N
Possible surface conditions are :
S1 black S2 pickled S3 cold rolled S4 coated to an agreed condition
Note: The surface conditions S1 and S3 apply for the strip. The surface condition S2 and S4 may apply for the strip or the tube; the purchaser should, where necessary, indicate the condition at the time of enquiry and order.
Tubes made of the steel grade E155 E195 E235 and E355 shall be supplied in the delivery condition +CR1 or +N. Tubes made of the grades E190 E220 E260 E320 E370 and E420 shall be supplied in the delivery conditions +CR2