Brass Straight Union is a type of fitting that is used to connect two pipes or tubes of the same diameter in a straight line. It is typically made of brass, a material known for its durability and resistance to corrosion. The union has two female threaded ends that can be screwed onto the pipes or tubes to create a tight and secure seal. Brass Straight Union type of fitting is commonly used in plumbing and other fluid transfer applications, where a leak-proof connection is critical.