Cashco 345 - Manual (Page 4)

4 IOM-345
NOTE: When piston (15) assemblies are used with comp
seats, Cashco, Inc. does not recom mend attempting to
remove the comp seat. If composition seat is damaged,
replace entire piston assembly.
A. Oversized regulator; inadequate rangeability. A1. Check actual fl ow conditions, re-size regulator for minimum and maximum
fl ow.
A2. Increase fl ow rate.
A3. Decrease regulator pressure drop; decrease inlet pressure by placing a
throttling orifi ce in inlet piping union.
A4. Install next step higher range spring.
A5. Before replacing regulator contact factory.
B. Worn piston/cylinder; inadequate guiding. B. Replace trim.
C. Weakened/broken piston spring. C. Replace piston spring.
SECTION VII
Vll. TROUBLE SHOOTING GUIDE
Possible Causes Remedies
1. Erratic operation.
Remedies Possible Causes
A. Plugged piston balance port. A. Remove trim and clean balance port.
B. Fluid too viscous. B. Heat fl uid. Contact factory.
2. Sluggish operation.
11. Bench test unit for suitable operation. NOTE:
Regu la tors are not tight shutoff devices. Even if
pressure builds up beyond set point, a regu la tor
may or may not de velop bubble tight shutoff. In
general, tighter shutoff can be expected with com-
po si tion seat.
12. Soap test around body cap (5) and body(1) for leak-
age. Test pressure should be a minimum of 100
psig (6.9 Barg) at the inlet and leakage de ter mined
by bubbles.
D. Trim Replacement (For TFE Seated Units):
1. Follow same steps as listed under trim re place ment
for metal seated units, except for the fol low ing
guidelines:
a. After removing the body cap(5) (C.2), inspect
the inside surface of the body cap for scratches
or nicks. These could result in leakage past the
quad ring (19) and backup ring (20). If worn
or scratched replace the body cap (5).
b. When inspecting parts for excessive wear
(C.3), assure there are no foreign particles
embedded in the tefl on seat. Inspect for nicks.
Inspect the backup ring (20) and quad ring (19)
on piston post.
c. Remove the body cap o-ring (13) and clean
con tact ing sur face of body.
2. To check for seat leakage, follow same steps as
listed under Pressure Piston/O-ring Inspection/Re-
placement, except for the following guide lines:
a. Pour a small amount of water in on top of the
piston (through pressure piston bore in body).
Crack open inlet pressure (50 psig maximum)
to body and visu ally check for leakage by the
cylinder gasket (18), TFE seat (15), or the body
quad ring (19). After inspection, assure that
water is removed before completing assembly
and installing in line.