Cashco 5500 - Manual (Page 4)

4 IOM-5500
SECTION VI
VI. PILOT MAINTENANCE:
A. General:
1. Maintenance procedures herein after are
based upon removal of the pilot/vent valve
unit from the vessel/piping where installed.
 1YPGT UJQWNF TGHGT VQ QYPGTŏU RTQEGFWTGU HQT
removal, handling and cleaning of nonreus-
CDNG RCTVU KG ICUMGVU UWKVCDNG UQNXGPVU
etc.
3. All indicated Item Numbers that are with
respect to the Pilot Assembly will be in
RCTGPVJGUKU CPF WPFGTUEQTGF KG
). All
Item Numbers that are with respect to the
8GPV 8CNXG CTG PQV WPFGTUEQTGF KG
 
B. Separation from Main Valve and Disassembly:
 &KUEQPPGEV UGPUG VWDG
 HTQO ſVVKPIU
(48) and (). Remove the pilot valve as-
sembly from the nipple (53) by rotating the
pilot body () CCW.
 5GEWTG DQF[
 KP XKUG YKVJ ŎUGPUKPIŒ
port facing front. Disconnect tubing ()
from connectors (),().
3. Paint or embed a match mark between
upper case (), spacer () and lower
case ( CNQPI ƀCPIGF CTGC NOTE lo-
ECVKQP QH Π026 VCR HTQO GNDQY
234) in
relation to body sensing port and straight
EQPPGEVQT
232).
4. Rotate the closing cap () CCW for
TGOQXCN .QQUGP VJG CFLWUVKPI UETGY PWV
( VYQ TGXQNWVKQPU
4QVCVG #FLWUVKPI
screw () CCW and remove.
5. Remove diaphragm case nuts (),
lockwashers (  ƀCV YCUJGTU
) and
cap screws ( . Grasp spring bonnet
() and lift up until diaphragm case ()
clears top of spring button ().
6. Secure spring bonnet () in a vice with
the upper diaphragm case () orientated
upwards.

7UG ΠCNNGP YTGPEJ VQ TGOQXG ECR
screws () and lock washers () to
separate the bonnet () from the upper
case (). Replace bonnet gasket ()
and reassemble item numbers (, ,
 and ). Remove bonnet from vice
and set assembly aside.
8. Lift range spring () and spring button
  WR CPF UGV CUKFG
 )TCUR VJG ƀCV UWTHCEGU QH YTGPEJ YCUJGTU
() with a wrench and rotate piston stud
nut () CCW to remove nut, lock washer
(), spring guide (), washers ().
10. Remove pressure ring (), upper
pressure plate (), upper diaphragm
() and spacer ().
11. Remove upper diaphragm washer (),
upper diaphragm gasket (), and
diaphragm spacer ().
 4GOQXG NQYGT RTGUUWTG RNCVG
), lower
diaphragm (), lower diaphragm washer
() and lower diaphragm gasket ().
 4QVCVG ΠJGZ JGCF ECR UETGYU
)
CCW and remove lock washers ().
Lift up on lower diaphragm case () to
remove. NOTE the alignment of the four
DQNV JQNGU CPF VJG UGPUG JQNG KP ECUG
203)
YKVJ VJG JQNGU KP VJG DQF[
201).
14. Grasp the cylinder () / piston ()
assembly and lift upwards to extract this
assembly from the body (). Remove
upper and lower body gaskets ().
15. From top of assembly, press piston stud
() / piston () downward through
the center of the cylinder () to remove.
Apply Dow Corning 111 lubricant in o-ring
grooves and install new piston O-rings
().
WARNING
524+0) 70&'4 %1/24'55+10 2TKQT VQ TGOQXKPI
ƀCPIG DQNVU TGNKGXG URTKPI EQORTGUUKQP D[ DCEMKPI
QWV VJG CFLWUVKPI UETGY (CKNWTG VQ FQ UQ OC[ TGUWNV
KP ƀ[KPI RCTVU VJCV EQWNF ECWUG RGTUQPCN KPLWT[
(QT +PVGTOGFKCVG *KIJ 2TGUUWTG 2KNQVU 1PN[
Remove diaphragm case gasket ()
and pressure ring ().