RKI Instruments Digester Gas Monitor - Manual (Page 37)

Digester Gas Monitor Operator’s Manual Making Fitting Connections • 31
Fresh Air Inlet, Dryer Exhaust, and Digester Sample Inlet Fittings
1. Install the desired length of 1/4 inch OD rigid metal or rigid plastic tube into the tube
nut and ferrules as shown in the figure below. Stainless steel, Teflon, or polypropylene
tubing is recommended.
Figure 19: Compression Fitting Connection
2. Before tightening the nut, be sure to hold the fitting still so it does not rotate using a
5/8 inch open-end wrench or an adjustable wrench. The dryer exhaust and fresh air
inlet fittings will have to be held from the inside of the housing while the sample inlet
fitting will have to held from the outside (see Figure 19). While holding the fitting still,
firmly tighten the nut with a 9/16 inch open-end wrench or an adjustable wrench so the
ferrules crimp onto the sample tubing and make a seal.
3. Route the tubing to the desired area. The fresh air inlet tubing needs to routed to a
fresh air environment while the digester sample inlet needs to be routed to the desired
sampling area.
Hose Barb Connections
1. The blowback exhaust discharges contents from the filters and water trap. It will
contain corrosive gas and particulate or liquid discharge. For this reason, the
blowback exhaust needs to be routed into a container where it may be safely
discharged. Connect up to 20 feet of 3/16 inch ID flexible tube to the blowback
exhaust fitting and route it to a container.
2. Connect up to 100 feet of 1/4 inch ID flexible tube to the aspirator/sample exhaust
fitting and route it to a fresh air area where it can be safely discharged.
Hold Still (5/8 inch)
Ferrule Ferrule
Nut (9/16 inch) Nut (9/16 inch)
Sample Inlet Fitting
1/4 inch OD
rigid metal or
rigid plastic
tubing 1/4 inch OD
rigid metal or
rigid plastic
tubing
Hold Still (5/8 inch)
Dryer Exhaust and
Fresh Air Inlet Fittings