Way Valve Function Test - Invacare Perfecto 2 Series Service Manual

4 Way Valve Function Test

NOTE: For this procedure, refer to FIGURE 23.1 on page 78.
The 4-way valve used in the Perfecto2 Series Concentrators does have an acceptable
tolerance of leakage per RexRoth
By nature of the valve design it is possible for the valve to experience small leaks, and still
operate without affecting the overall performance of the unit. The valve is assembled
where the components that make up the valve "Snap" together. The only screws in the
valve are for securing the valve to the manifold assembly.
According to RexRoth there is an acceptable leak specification of 60 cc per minute at 20
psi on each valve. Valves that have leaks within this specification will function properly
without any adverse effects to the performance of the concentrator. A leak in the amount
of 60 cc or less would be indicative of the type of small leak you would notice where the
end caps connect to the main body or where the three pieces of the main body connect
together. A 60 cc leak would not be noticeable when examining the system pressure
swings.
Leaks greater than 60 cc are indicative of cracks in the end caps, or a blown seal where the
end cap connects to the main body of the valve. These leaks are detected by either reading
the system swing pressures, noticing two consecutive swings not being equal or by
hearing an audible leak every other cycle. Leaks of this extreme nature indicate the valve
needs to be replaced.
Valves should only need to be replaced when the following conditions exist:
1. A visible crack is noted on either of the end caps or main body of the 4 way valve,
regardless of the amount of leak.
2. A large leak is present on the valve that causes an imbalance in the sieve bed swing
pressures. Example: Sieve Bed 1 pressure swings from 14 psi to 16 psi, within 7-20
seconds and Sieve Bed 2 pressure swings from 13 psi to 16 psi slowly, and may take as
long as 25-30 seconds before shifting (times over 30 second will shut down
automatically).
3. Valve will not shift and the pilot valve solenoid and circuit board are working
properly.
NOTE: The concentrator's P.C.B. should exhibit an error code for High Pressure Failure (1 Red/
2 Green).
NOTE: The best method to test the 4-way valve operation is by measuring the unit pressure
swings. This can easily be done at the HomeFill port with a 0-30 psi pressure gauge and a ¼" fill
line adapter. Upon starting the unit should build pressure up to 16 psi for output flows 3 L/min
and below or 21 psi for output flows 4 L/min and above before its initial shift. After the initial shift
the unit should shift consistently in equal amounts of time +/- 1 second (time recorded in seconds).
Part No 1148070
®
.
79
SECTION 23—LEAK TEST
Perfecto
™
2