REVENUE RECOGNITION

The following table presents the Company's Net sales disaggregated by product line:



	Year Ended December 31,
	2018
Consumables	$	1,755,652
Equipment	1,273,022
Net sales	$	3,028,674

Consumable sales consist of electrodes, fluxes, specialty welding consumables and brazing and soldering alloys. Equipment sales consist of arc welding power sources, welding accessories, fabrication, plasma cutters, wire feeding systems, robotic welding packages, integrated automation systems, fume extraction equipment, CNC plasma and oxy-fuel cutting systems and regulators and torches used in oxy-fuel welding, cutting and brazing. Consumable and Equipment products are sold within each of the Company’s operating segments.

Substantially all of the Company's sales arrangements are short-term in nature involving a single performance obligation. The Company recognizes revenue when the performance obligation is satisfied and control of the product is transferred to the customer based upon shipping terms.

Within the Equipment product line, there are certain customer contracts related to automation products that may include multiple performance obligations. For such arrangements, the Company allocates revenue to each performance obligation based on its relative standalone selling price. The Company generally determines the standalone selling price based on the prices charged to customers or using expected cost plus margin. In addition, certain customized automation performance obligations within the Equipment product line, are accounted for over time. Under this method, revenue recognition is primarily based upon the ratio of costs incurred to date compared with estimated total costs to complete. The cumulative impact of revisions to total estimated costs is reflected in the period of the change, including anticipated losses. Less than 10% of the Company's Net sales are recognized over time.

At December 31, 2018, the Company recorded $17,023 related to advance customer payments and $17,013 related to billings in excess of revenue recognized. These contract liabilities are included in Other current liabilities in the Condensed Consolidated Balance Sheets. At January 1, 2018, the balances related to advance customer payments and billings in excess of revenue recognized were $19,683 and $11,132, respectively. Substantially all of the Company’s contract liabilities are recognized within twelve months based on contract duration. The Company records an asset for contracts where it has recognized revenue, but has not yet invoiced the customer for goods or services. At December 31, 2018 and January 1, 2018, $25,032 and $22,229, respectively, related to these future customer receivables was included in Other current assets in the Condensed Consolidated Balance Sheets. Contract asset amounts are expected to be billed within the next twelve months.