Personalized Funny Hydraulic Engineer Youth T-Shirt. Funny Hydraulic Engineer Youth T-Shirt - Kelly Green say "Flow Rate Beer Hydraulic Engineer" in black text and makes a fun gift design for ale loving engineers! Let the good times roll in a durable T-Shirt that takes kids from school to play in an amazing array of colors. 5.0 oz., pre-shrunk 100% cotton. Seamless 1x1 rib collar.