Ratio Regulator Selas Model BZR-B
Selas Model BZR-B ratio regulator, product #5106, is designed with an adjustable compensation spring to bias the regulator providing a smooth transition to excess air operation at low fire.
The BRZ-B ratio regulator is designed for ambient temperatures up to a continuous operating range of 150 F. For precise control of heated gases or higher ambient operating conditions, Model BRZ-B-300 is available.
Using a gas adjuster downstream of a negative biased regulator, high fire can be set to stoichiometric conditions. As the system is turned down, the spring bias will subtract from the combustion air pressure causing the burner/gas ratio to go lean. Adjusting the screw under the cap assembly permits biasing the fuel/air ratio from high fire to low fire at a fixed, controlled rate.
As shipped, the regulator is set at zero bias.
Features and Benefits
- Accuracy: Low – Flow: 0.1 W.C., Full – Flow: 0.3 W.C.
- Turndown up to 20:1
- Continuous operation to 150 °F
- All units factory tested and sealed before shipment
- Maximum inlet pressure: 2.0 psig
- Minimum pressure drop through regulator: 4.0 W.C.
- Sensitivity – Responds to signal pressure differential as low as 0.04 W.C.
- Adjustable spring bias from: + 0.3/-5.0 W.C.
