External types feature:
- Air filter.
- Threaded connection (Type 1).
- Barbed connection (Types 2 and 3).
- Color coding (Types 2 and 3).
- Airflow direction arrow to minimize installation errors.
- Airflow restrictor capacity molded (Types 2 and 3) or stamped (Type 1) on
External restrictors are used:
- for one-pipe transmitters, 40 scim (11 ml/sec).
- when installed tubing lengths exceed maximum recommended value. and 2.
- for one-pipe room thermostats, 20 scim (5.5 ml/sec).
- with check valves to provide airflow time delays.
- Slow to supply, fast to exhaust.
- Fast to supply, slow to exhaust.
- for VAV vortex control. Use 80 scim (22 ml/sec) restrictor in actuator control pressure line to prevent cycling.
- when other air capacities, 10 scim (2.7 ml/sec), 80 scim (22 ml/sec) or 320 scim (87 ml/sec), are required to compensate for tubing size or response time.