Instruction Manual
D200156X012
4194HA, HB, HC Controllers
July 2018
78
3. Position the ball (key 279), the tube (key 278), and the ball seats (key 280) between the ears of the loader
assemblies (keys 282 and 274); position the diaphragm assembly (key 281) between the main halves of the loader
assemblies.
Note
The tube (key 278) must be well‐seated in the cups of the ball seats (key 280).
4. Bolt the loader assembly halves together using the four screws (key 289).
Note
Be sure the supply and exhaust seats of the loader are correctly aligned. Misalignment will impair loader performance.
5. Attach the tubing assembly (key 309).
6. Perform the assembly portion in the replacing the auto/manual station procedure.
Replacing the Auto/Manual Station Loader Valve Plug and Valve Plug Spring
Refer to figure 6‐5 for key number location.
1. Loosen the spring seat screw (key 275).
2. Remove the valve plug spring (key 276) and the valve plug (key 277).
3. Inspect the parts and replace as necessary.
4. Install the valve plug spring and valve plug.
5. Tighten the spring seat screw.
6. Temporarily apply supply pressure and process differential pressure and check for leaks.
7. Install the controller assembly in the case. Slide the controller frame down to assure an O‐ring seal at the pressure
connections. Hold the frame in place.
8. Install and tighten the nine screws holding the controller assembly in the case.