Jargon Buster - U

U seal
A bent pipe shaped like a ‘U’. It is typically used to create a water seal to prevent the passage of steam.
U value
A way of describing the overall heat flow coefficient of a building or system. It is typically expressed in W/m^2 °C.
Ultrasonic steam trap testing
A method of testing if steam traps are working correctly. An ultrasonic listening device is placed on the steam trap and the operator listens to the noise to determine if the steam trap is; working correctly, failed open, or failed closed. Due to differing condensate loads during operation it can be easy to miss identify a steam trap as faulty, when in fact it is working correctly. This type of testing should therefore be done by personnel correctly trained to use the ultrasonic listening device.
A type of pipe fitting which is used to couple two pieces of pipe together. A union allows for disconnection of the pipe if required at a later date.
Upstream pressure
A term used to describe the pressure upstream of a piece of equipment or plant.