cashco DA8 Installation, Operation & Maintenance Manual Download Page 9

IOM-DA8

9

d. Type 

NO:

1.  For “standard” flow direction ap pli ca-

 tions, it is not ab so lute ly required that 
a dynamic side seal (27) be installed. 
(When included with the dy nam ic seal 
(27), better guid ing of valve plug (20) 
results.) Type “NO” dynamic seal (27) 
means NO dynamic seal.

2.  The more common “Reverse” flow 

direction always requires a dynamic 
side seal (27).

7.  Place fluid compatible thread anti-seize, 

Locktite Corp., "Nickel Anti-Seize", or equal 
on thread ed por tion of di a phragm cap screw 
(7), sizes 1-1/4" and 1-1/2"; or, thread ed post 
por tion of valve plug (20), sizes 1/2" – 1" and 
2-1/2" – 4". (

 NOTE:

 Valves cleaned for ox y-

 gen ser vice should use Fisher Scientific Co., 
"Fluorolube GR-362", or equal.)

8.  Body sizes 1/2"-1", 2-1/2" through 4".

 

a.  Place o-ring lower stem seal (14.3) over 

upper-end of plug (20) and into groove in 
plug (20).

  b.  Place properly oriented piston/guide bear-

 ing (13) over up per-end of plug (20) and 
into po si tion on plug (20).  Note: Part name 
for item 13 on 1/2"-1" sizes is "spacer".

 

c.  Place o-ring middle seal (14.2) over up per-

end of plug (20) and into groove of piston/
guide bear ing (13).

 9.  Body sizes 1-1/4" through 2".
 

Place new o-ring mid dle stem seal (14.2) into 
groove of valve  plug (20) upper surface.

10. Position lower diaphragm pusher plate (10) 

on/over upper end of valve plug (20) properly 
oriented. For composition diaphragm con struc-
 tion the “tongue and groove” “ridge” should 
be on upper side, “flat” side down wards. For 
metal diaphragm construction the “rounded” 
surface of the lower diaphragm push er plate 
(10) should be on upper side, “flat” side down-
wards.

11.  For composition diaphragm construction, place 

new o-ring upper stem seal (14.1) on/over 
upper end of valve plug (20) and into groove 
of lower diaphragm pusher plate (10).

12.  For metal diaphragm construction, place 

com pat i ble gasket sealant on both sides and 
place new lower pusher plate gasket (14.4) 
on/over upper end of valve plug (20) and onto 
lower diaphragm pusher plate (10). (Gasket 
sealant is Federal Process Corp. “Gasoila” , 
or equal.)

13.  Position new diaphragm(s) (9) on/over upper 

end of valve plug (20). 

NOTE: 

For multiple 

diaphragms (9) that include TFE material, the 
TFE should be on the wetted side; for 6-ply 
elastomeric TFE diaphragm (9), stackup is
TFE-TFE-HK-HK-TFE-TFE, be gin ning with 
the low er wetted diaphragm (9) first.

14. Position upper diaphragm pressure plate (8) 

on/over upper end of valve plug (20) prop-
erly oriented.  For composition di a phragm 
con struc tion the "tongue and groove" "ridge" 
should be on lower side, "flat" side upwards.  
For metal diaphragm construction the "round-
 ed" surface of the upper diaphragm pressure 
plate (8) should be on lower side, "flat" side 
upwards.

15. 

a.  Body sizes 1/2" through 1": Engage 

di a phragm lock nut (7) to thread ed 
post por tion of valve plug (20) and 
torque to 60-70 ft-lbs. by rotating 
CW. 

  b.  Body Sizes 1-1/4" through  2": In sert 

anti-seize coat ed di a phragm cap 
screw (7) through stacked parts (8, 
9, 10, 14.1, 14.4) and into upper end 
of valve plug (20). Torque-tight en 
diaphragm cap screw (7) to 120-130 
ft-lbs.

  c.  Body Sizes 2-1/2" through 4": En gage 

di a phragm lock nut (7) to threaded 
post of valve plug (20) and wrench-
tight en firmly.  While restraining valve 
plug (20) from rotating by torque 
wrench on upper end 3/4" hex, use 
another wrench to tighten di a phragm 
locknut (7) to a torque of 180 - 200 
ft-lbs.

16.  This completes assembly of ITA; remove from 

vise.

 

F. Main 

Reassembly:

1.  Place body (23) in a vise.

2.  Fit the o-ring cage seal (15) into its body (23) 

groove.

3.  For metal diaphragm construction, place 

seal ant (“Gasoila” or equal) on both sides of 
diaphragm gasket (37) and position on body 
(23) diaphragm flange. 

4.  Position properly oriented lower cage gasket 

(21) onto lower shelf of cage (19).

Summary of Contents for DA8

Page 1: ...lowed to enter the regulator upon startup 7 FlowDirection Installsotheflowdirectionmatches the arrow cast on the body or other markings such as in and out 8 PrecautionforStandardDiaphragmConstruction...

Page 2: ...m piping to prevent water pockets whichallowsthediaphragmchamber to always be self draining The external sens ing line may be sloped upward for liquids or gases i e non condensable fluids Recommended...

Page 3: ...o not walk away and leave a bypassed regulator unattended 5 Slowly open the inlet upstream block valve to about 25 open observing the inlet upstream pressure gauge Determine if the regulator is flowin...

Page 4: ...or repairing regulators 4 Owner should refer to owner s procedures for removal handling cleaning and disposal of nonreusable parts i e gaskets etc NOTE On regulators originally supplied as SpecialClea...

Page 5: ...Figure 1 Dynamic Side Seals Type CP TFE Cap Dynamic Seal Type PR PRA Dynamic Seal Type UC U Cup Dynamic Seal Type NO No Dynamic Seal NOTE Two separate piston rings per assembly Standard Flow Only 1 1...

Page 6: ...removed metal parts C Disassembly of the ITA 1 Body Sizes 1 2 2 See Figures 2 through 4 a Obtain two pieces of square section barstock with a 3 8 7 16 dimension approximately 2 inches long b Place pl...

Page 7: ...rts should be free of surface contaminants burrs oxides and scale Rework and clean the parts as necessary Surface conditions thataffecttheregulatorperformancearestated below replace parts that can not...

Page 8: ...seal 27 1 edgetouchestheupperlipofthecage 19 While gently applying force to press the piston guide bushing 13 or valve plug 20 into the cage 19 simultaneously use fingers to lightly press the cap sea...

Page 9: ...agm construction place compatible gasket sealant on both sides and place new lower pusher plate gasket 14 4 on over upper end of valve plug 20 and onto lower diaphragm pusher plate 10 Gasket sealant i...

Page 10: ...ck off range spring assembly a fraction of the turntoalignthemilledslotsperpendicular to the center line of the valve body The slots should now be ready to accept the internal ribs of the spring chamb...

Page 11: ...kage a Determine test pressure If upper value of range spring is less than 55 psig use test pressure of 5 psig less than upper value of range spring If upper value of range spring is greater than 55 p...

Page 12: ...t regulator outlet as close as possible to outlet port etc Following are some of the more common complaints along with possible causes and remedies SECTION VIII Possible Causes Remedies A Sticking of...

Page 13: ...contains trim replacement parts plus seal s diaphragm s and gasket s Step 3 Contact your local KM Sales Representative and specify the product code number along with a description of any parts not in...

Page 14: ...IOM DA8 14 Figure 2 Composition Diaphragm FTO Reverse Flow Direction...

Page 15: ...Cage Seal 18 Cage Cap Screws Item No Description 19 Cage 20 Valve Plug 21 Lower Cage Gasket 23 Body 24 Lower Guide Bushing 26 Tap Plug Not Shown 27 Dynamic Side Seal 27 1 TFE Cap Seal 27 2 O ring Ener...

Page 16: ...are presented for informational purposes only and while every effort has been made to ensure their accuracy they are not to be con strued as warranties or guarantees express or implied regarding the p...

Page 17: ...The details of the assessment in terms of the individual Essential Health and Safety Requirements are listed in Table 1 Table 2 lists all of the models and options that were evaluated and along with...

Page 18: ...e same requirements for the piping system Also see item 30 in Table 1 2 The system designer and users must take precautions to prevent rapid system pressurization which may raise surface temperatures...

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