This #42 drill size orifice is manufactured to strict OEM tolerances

these gaskets maintain a reliable seal at temperatures up to 300°F (149°C)

a reading below 1

Can this link be field-installed to change a damper's temperature rating

Schneider Electric (Barber Colman) 21-153 Restrictor This #42 drill size orificeThe Schneider Electric (Barber Colman) 21 153 In Line Restrictor is a critical pneumatic component engineered for precise airflow regulation in HVAC control systems. Specifically designed for use with NCS TUBE or standard 1 4" poly tube, this 0. 007 orifice restrictor provides a calibrated flow rate of 1. 0 SCFH (28. 32 L H) at a 20 psig reference. This component is essential for maintaining signal stability in transmitters and bleed type units,