Standard 1/4″ monel tubing are closed at one (flat) end, and have a laser drilled hole in your choice of diameter.
Monel tubing orifices can be used with ¼” fittings and valve components even at high pressures and temperatures. For critical flow orifices, restrictors, gas/liquid separators, particle counters and many other purposes.
Monel is impervious to the effects of steam, gas, salt water, ammonia, calcium chloride, and the acids associated with food products even at high temperatures.
Optically measured holes are not guaranteed to meet a specified flow rate.
Optically Measured Tolerances
Flow Calibrated Tolerances