Tee
Tee turns up in 2 fields: valves, shop slang. Here is what it means to the people in each one.
Tee in valves
A T-shaped fitting that splits or joins flow, with a straight run and a side branch.
Straight tees have all three openings the same size; reducing tees have a smaller branch. A tee is called by its run size and then branch size, for example 6 by 6 by 2. Flow entering the branch and splitting both ways along the run is called a bullhead arrangement, which adds turbulence and pressure drop, while branching off the run is the gentler path.
"Put a 4 by 2 reducing tee at the low point and bring the 2 inch down for a drain valve."
Tee in shop slang
To prepare a task, document, or situation so it is ready for immediate action.
The act of setting up a job or arranging the necessary components so that someone else can execute the final step without delay. It is often used with the word up. The phrase borrows from golf, where placing the ball on a peg makes it easier to strike.
"I'll tee up the purchase orders this afternoon so you can sign them first thing tomorrow."