Manual
IOM-DA5
8
be on upper side, “fl at” side down wards. For 
metal diaphragm construction the “rounded” 
surface of the lower diaphragm push er plate 
(10) should be on upper side, “fl at” 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.) A Tefl on gasket (37) may alternatively 
be  fi tted between diaphragm and fl ange  of 
body.
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 3-ply 
elastomeric TFE diaphragm (9), stackup is
TFE-HK-TFE, be gin ning with the low er wetted 
diaphragm (9) fi rst.
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, "fl at" side upwards.  
For metal diaphragm construction the "round-
 ed" surface of the upper diaphragm pressure 
plate (8) should be on lower side, "fl at" side 
upwards.
15.  a.  Body sizes 1/2" thru 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" thru 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" thru 4": En gage di a-
 phragm lock nut (7) to threaded post 
of valve plug (20) and wrench-tight en 
fi rmly. 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.  Reinstall internal sensing drilled plug (32) with 
compatible thread sealant.
3.  Fit the o-ring cage seal (15) into its body (23) 
groove for reverse fl ow regulators.
4.  For metal diaphragm construction, place 
seal ant (“Gasoila” or equal) on both sides of 
diaphragm gasket (37) and position on body 
(23) diaphragm fl ange. 
5.  Position properly oriented lower cage gasket 
(21) onto lower shoulder of cage (19).
6.  Insert cage (19) into body (23) recess. Prop er ly 
align all three cage bolt (18) holes as there is 
only one cir cum fer en tial location pos si ble for 
this align ment. Engage all of the cage bolts 
(18), then evenly screw in the cage bolts in 
one-half revolution increments, tak ing care 
NOT TO “COCK” THE CAGE (19) IN THE 
BODY. Torque the cage bolts (18) to 13-15
ft-lbs.
7.  Dynamic Side Seals:
a.  Type CP: Position the ITA's valve plug 
(20) lower end over and into upper end 
of cage (19) until the cap seal (27.1) edge 
touch es the upper lip of the cage (19). 
While gently ap ply ing force to press the 
valve plug (20) into the cage (19), si mul ta-
 neous ly use hand thumbs to light ly press 
the cap seal (27.1) inwards into the groove 
of the valve plug (20) until the cap seal 
(27.1) “slips into” the cage (19). DO NOT 
USE TOOLS, LU BRI CANT, OR HEAVY 
FORCE TO ENGAGE THE CAP SEAL 
(27.1) INTO THE CAGE (19). Do not press 
inwards on the cap seal (27.1) too much 
or the cap seal (27.1) may slide out of its 
groove.
b.  Type PR: Position the ITA's valve plug 
(20) lower end over and into upper end 
of cage (19) until the lower piston ring 
seal (27.5) touch es the upper lip of the 
cage (19). While gently applying force to 
press the valve plug (20) into the cage 
(19), simultaneously use fi ngers to lightly 










