Pump Solutions Group Neptune Series 500 MODEL 481 THRU 547 - Manual (Page 20)

17
SECTION VI
SEE ELECTRIC STROKE CONTROL INSTRUCTION MANUAL
FOR PUMPS FURNISHED WITH OPTIONAL ELECTRIC STROKE CONTROL.
SPECIAL INSTRUCTIONS FOR SERIES 500 “dia-Pumps”
WITH PNEUMATIC STROKE CONTROL
17.0 FUNCTION OF THE PNEUMATIC STROKE CONTROL UNIT
The Neptune pneumatic stroke control unit controls the capacity of the “dia-Pump” over the full operating
range. Control is normally effected by an instrument air signal of 3 to 15 psi applied to a Moore Products
Model 73N control valve (other air signal parameters also available), which is an integral part of Neptune
stroke control unit.
The variation of instrument air signal changes the air pressure on the Diaphragm (FIG. #583) in the control
unit, which in turn changes the position of the Pump Capacity Control Rod (FIG. #570).
The position change of the control unit can be observed on a capacity percentage scale seen through the
clear plexi-glass shell of the control unit.
The pneumatic control unit may be attached to any standard simplex or duplex Series 500”dia-Pump”.
The operating range of supply air may vary between 40 and 80 psi. The Moore control valve is preset at the
factory for a supply air pressure of 60 psi.
The “Pneumatic Stroke Control Unit” is accurately preset and tested at the factory. If the unit does not appear
to perform correctly, please contact your local representative or the factory. Do not attempt to adjust the unit
in the field without factory advise.
17.0.1 The Moore control valve which is attached to the Neptune actuator supplies a varying air pressure to
the Flexible Diaphragm (FIG. #583) which is in turn, balanced by Operating Spring (FIG. #587). The
Capacity Control Rod (FIG. #570) is attached to this system.
With the required air signal, the Moore control valve maintains the correct constant air pressure on
the Flexible Diaphragm (FIG. #583); i.e. constant position of the Capacity Control Rod (FIG. #570).
The springs in the actuator and Moore control valve insure that the controlled position of the
diaphragm (i.e. capacity control rod). Supply air and instrument input ports are clearly marked on the
Moore Control Valve.
The Moore control valve connections are marked for “Supply Air” and “Instrument Air”. It is important
that clean, dry air be furnished to the “Pneumatic Stroke Control Unit”. Cross sectional drawings of
the complete unit and the Moore control valve are included with instruction manual.
17.0.2 Maintenance
The Neptune “Pneumatic Stroke Control Unit” is normally maintenance free.
17.0.3 Moore Control Valve
If more complete information is required on the Moore Model 73N control valve, request Moore
Bulletin #SD73-5 in writing from Neptune.
MODEL/SPEED/SIZE CHART
STROKING SPEED
PISTON
SIZE 18 SPM 37SPM 72 SPM 117SPM 144 SMP 175 SPM
½” 501 500/510 512 515 517
11/16” 520 522 525 527
1-1/16” 530 532 535 537 538
1-3/16” 547