Instruction Manual
D100391X012
EDR and ETR Valves
March 2016
8
D
For EDR,
if the piston ring (key 6) is visibly damaged, remove the ring and replace it with a new part. Refer to the
Parts List at the end of this manual for a replacement part.
D
For ETR,
if the seal ring and backup ring (keys 24 and 25) are visibly damaged, remove the rings by prying or cutting
them from the groove. Be careful not to scratch valve plug surfaces. Refer to the Parts List at the end of this manual
for replacement parts.
Assembling the Valve Plug and Stem
1.
For EDR and ETR,
perform the following steps:
D
Insert the stem (key 7) into the plug (key 2, figure 3) and thread the castle nut (key 8) onto the end of the stem and
hand tighten.
CAUTION
To prevent possible product damage, take care that the stem and plug are not damaged during the following tightening
procedure.
D
When tightening the castle nut with a wrench, line up the hole in the end of the stem with a slot in the castle nut.
Ensure that the stem and plug are not damaged during the tightening procedure.
D
Insert the cotter pin (key 30) and lock it in place.
Installing the Piston Rings or Backup Ring/Seal Rings
1.
For EDR:
When using a carbon‐filled PTFE piston ring, spread the ring apart slightly at the split, start one end of the
split into the groove in the valve plug. Work the ring around the valve plug inserting the ring into the groove in the
valve plug.
The replacement graphite piston rings will arrive in one piece. Use a vise with smooth or tapered jaws to break the
replacement piston ring into two halves. Place the new ring in the vise so that the jaws compress the ring into an oval.
Compress the ring slowly until the ring snaps on both sides. If one side snaps first, do not try to tear or cut the other
side. Instead, keep compressing the ring until the other side snaps. The piston ring can also be fractured by scoring and
snapping over a hard surface such as a table edge. Sawing or cutting the ring is not recommended.
2.
For ETR:
Apply a lubricant to both backup and seal rings (keys 25 and 24). Place the backup ring over the stem (key
7) and into the groove in the valve plug (key 3). Slowly and gently stretch the seal ring over the valve plug and work
it into the groove. Stretching the ring over the valve plug can cause it to appear too large for the groove, but it will
contract to its original size when inserted into the cage.
CAUTION
When installing the EDR or ETR valve plug into the cage, make sure the piston or seal ring is evenly engaged in the entrance
chamfer of the cage to avoid damage to the ring.
Note
Use the preceding procedures to assemble the valve plug and stem before installing the parts into the valve body. Insert the valve
plug into the cage (figure 3), then stack the parts as recommended in steps below.
