1. n. [Shale Gas, Well Completions, Well Workover and Intervention]
A Christmas tree installed specifically for the fracturing process. A frac tree typically consists of upper and lower master valves, flow cross, wing valves, goat head, and swab valve. Frac trees generally have larger bores and higher pressure ratings than production trees to accommodate the high flow rates and pressures necessary for hydraulic fracturing.
Alternate Form: frac stack
See: composite frac tree