All new Carrier/Carlyle capacity control valves for the 06D and 06E compressors are shipped with a by-pass piston. This piston is not factory installed onto the valve on either the electric or pressure control valves. It must be field installed if used.
The use of this piston is determined by what type of capacity control the compressor has. The suction cut-off unloader system does not use the by-pass piston and it is discarded, however, the piston must be used on the hot gas by-pass unloader. On the suction cut-off unloader system, remove the blocking sleeve from the head and install the control valve with out the by-pass piston.
On the hot gas by-pass system, remove the by-pass plug and spring from the head, install the by-pass piston that came with the control valve onto the control valve and then install the assembly on the head using the new screws that came with the control valve. Do not use the screws that were used on the flange.