Practical Pointers | Fives North American

PREMIX SYSTEMS

TROUBLE SHOOTING AIR/GAS RATIO REGULATORS ATMOSPHERIC SERVICE ON PREMIX SYSTEMS

A. Symptom: At high fire, outlet pressure goes negative or flame goes lean Causes:

1. Insufficient supply pressure or supply line is undersized. 2. Regulator is undersized. 3. Leak around lower diaphragm or adjustment plug. 4. Hole in large diaphragm.

B. Symptom: Fire goes rich at "Low"

Causes: 1. Spring adjustment set "positive." 2. Hole in small diaphragm.

3. Limiting orifice open beyond normal to compensate for any conditions under "A." 4. Regulator vent not cross-connected to combustion chamber which has negative pressure. 5. Valve not seating because of dirt or damage.

C. Symptom: Fire goes lean at "Low"

Causes: 1. Spring adjustment set "negative."

2. Regulator vent not cross-connected to combustion chamber which has positive pressure.

16

Made with FlippingBook - Online catalogs