On March 24, 2020, in Cargo Systems Messaging Service (CSMS) #42133823, U.S. Customs and Border Protection (CBP) issued guidance on entries of pipe spools from multiple countries of origin. 

Filers are required to break our each component by country of origin.  If the pipe spool has components from multiple countries and/or has components that are subject to requirements such as antidumping duties, countervailing duties, Section 232 or 301 duties, or quotas, the pipe spool should be on multiple lines to reflect the different country and requirements.

The tariff classification should be that of the entire pipe spool, and the value on each line should reflect the value of that component.  The documentation should provide sufficient information to determine the breakdown of value, quantity, classification, and country of origin of the components.

CSMS #42133823 includes an example of how to declare pipe spools of multiple countries of origin and can be found here:

https://content.govdelivery.com/bulletins/gd/USDHSCBP-282e93f?wgt_ref=USDHSCBP_WIDGET_2