Orifice Flanges are a simple device with welding ends, for securely holding an orifice plate in a pipe.
Orifices can be best used for clean and non-corrosive fluids, if sufficent straight inlet pipe section is available and a higher pressure loss is allowed. SEIKO standard orifice flanges are made of forged carbon steel or stainless steel. Other materials are available.
The typical uncertainty of uncalibrated orifice plates is +/-0,5%