AERCO ECS Retrofit - Manual (Page 16)

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2.5.3 Self-Contained Control Valve Actuator Removal
Refer to Figure 2-6 and remove the Self-Contained Valve Actuator as follows:
1. Loosen the locknut on the thermal element adjustment sleeve. Unscrew the adjustment sleeve
to remove the sleeve and thermal element from the Actuator.
2. Carefully loosen the compression fittings on the upstream and downstream tubing to relieve
any trapped pressure buildup. Completely remove both the upstream and downstream tubing
assemblies and compression fittings. The tapped NPT ports in the Valve Body will be plugged
during the replacement procedures in Section 3.
3. Remove the hex head cap screws securing the Actuator to the Valve Body. Valve sizes from
1” to 2” have 6 cap screws, while sizes 2 ½” to 4” Valves have 8 cap screws.
CAUTION
Use care when performing step 4 to avoid damaging or scratching internal
Valve Body parts. It is imperative that the Actuator be lifted straight up to avoid
sticking or binding.
4. Lift the Actuator Housing straight up and off the Valve Body. Doing so will also remove the
entire inner valve assembly (Figure 2-7), including the Valve Stem, Seat, Valve Plug Shaft and
Top/Bottom Pistons. Depending on the age and condition of the valve, considerable force may
be required to pull the Pistons through the Valve Body. If it cannot be removed, the Valve
Stem may be used as an impact hammer to remove scale build-up on the internal valve
surfaces and allow Piston removal.
Replacement parts for these removed items are provided in the applicable Retrofit Kit for the
Valve size being retrofitted. These items will be replaced in Section 3. The Retrofit Kit also
contains a new Lower Shaft, Valve Top/Gasket, plus additional replacement items for the
Valve being retrofitted.
5. Proceed as follows, depending on the size of the Valve being retrofitted:
(a) For 2 ½ to 4 inch Valves, separate the Valve Seat Retaining Disc from the Valve Seat by
removing the four (4) cap screws (Figure 2-7).
(b) For 1 to 2 inch Valves, hold the Valve Plug Shaft with a pair of pliers and remove the
Valve Stem Retaining Nut from the Shaft (Figure 2-8).
6. Insert a 1/8 inch steel rod through the hole near the top of the Valve Stem (Figure 2-7 or 2-8).
NOTE
If “flats” are provided on the Actuator Connecting Shaft and Valve Stem, open-
end wrenches may be used in step 7 to disconnect the Valve Stem and
Actuator Shaft.
7. Grasp the Actuator Connecting Shaft (Figure 2-7 or 2-8) with a pair of pliers. Carefully turn the
Valve Stem counterclockwise and separate it from the Actuator Connecting Shaft.