Instruction Manual
D102175X012
EZ-C, ET-C, and EWT-C Valves
July 2017
13
1. Remove the actuator and the bonnet according to steps 1 through 9 of the Replacing Packing procedure in the
Maintenance section.
WARNING
To avoid personal injury due to leaking fluids, avoid damaging gasket sealing surfaces.
The surface finish of the valve stem (key 7) is critical for making a good packing seal.
The inside surface of the cage (key 3) is critical for tight shutoff and smooth operation of the valve plug.
The seating surfaces of the valve plug (key 2) and seat ring (key 9) are critical for proper shutoff.
Protect these surfaces accordingly.
Perform the following steps to remove the valve trim.
2. Remove the load ring (key 26) from an NPS 8 ET‐C or NPS 10X8 EWT‐C valve, and wrap it for protection.
3. Remove the plug and stem assembly from the valve body. The cage (key 3) might come out of the valve body with
the plug, due to seal ring friction.
a. If so, carefully separate the cage from the plug and stem assembly.
b. If the cage was not removed from the valve body with the plug and stem assembly, remove it, the associated
gaskets (keys 10 and 12), and shim (key 51).
4. Remove the seat ring (key 9) and seat ring gasket (key 13). Composition seat constructions use a disk (key 23)
sandwiched between a disk seat (key 22) and disk retainer (key 21).
5. Clean, inspect, and if necessary obtain replacement parts.
ET‐C and EWT‐C Valve Plug Maintenance
CAUTION
To avoid the valve plug seal ring (key 28) not sealing properly and affecting valve performance, be careful not to scratch the
surfaces of the ring groove on the valve plug or any of the surfaces of the replacement ring.
1. With the valve plug (key 2) removed, according to the disassembly portion of the Trim Maintenance procedure,
proceed as follows:
2. The spring‐loaded seal ring may be removed by first working the retaining ring (key 27) off with a screwdriver. Then
carefully slide the metal backup ring (key 29) and seal ring (key 28) off the valve plug (key 2).
3. A spring‐loaded seal ring must be installed so that its open side faces toward the valve stem, or toward the seat of
the plug depending on flow direction, as shown in view A of figure 9. To install a spring‐loaded seal ring, slide the
seal ring (key 28) onto the valve plug followed by the metal backup ring (key 29).
4. Then install the retaining ring (key 27) by inserting one end in the groove and, while turning the plug, press the ring
into the groove. Again, be careful not to scratch any surfaces of the ring or plug.
CAUTION
To avoid weakening the stem that may cause failure in service, never reuse an old stem with a new valve plug. Using an old
stem with a new plug requires drilling a new pin hole in the stem, which will weaken the stem. However, a used valve plug
may be reused with a new stem.
