BLACKMER SNP1.25, Installation, Operation And Maintenance Instructions

104-A00    Page 6/16 

OPERATION 

RUNNING THE PUMP IN REVERSE ROTATION 

NOTICE: 

Operate the pump in reverse rotation for no more than 10 
minutes and only when a separate pressure relief valve 
is installed to protect the pump from excessive pressure. 

It may be desirable to run the pump in reverse rotation for 
system maintenance.  The pump will operate satisfactorily in 
reverse rotation for a LIMITED time, 

at a reduced 

performance level. 

FLUSHING THE PUMP 

NOTICE: 

If flushing fluid is to be left in the pump for an extended 
time, it must be a lubricating, non-corrosive fluid.  If a 
corrosive or non-lubricating fluid is used, it must be 
flushed from the pump immediately. 

1.  To flush the pump, run the pump with the discharge 

valve open and the intake valve closed.  Bleed air into 
the pump through the intake gauge plug hole or through 
a larger auxiliary fitting in the intake piping.  Pump air for 
30 second intervals to clean out most of the pumpage.  A 
drain plug is provided on the bottom of the cylinder to 
facilitate cleaning. 

2.  Run a system compatible flushing fluid through the pump 

for one minute to clear out the remainder of the original 
pumpage.  Restrict a valve in the discharge line to build 
up 10 psi (0.7 bar) to force flushing liquid through the 
bearing seal chamber. 

3.  To flush out the pressure relief valve (if equipped), close 

the valve in the discharge line for 15 seconds while 
pumping the flushing liquid. 

4.  If necessary, repeat steps 2 and 3.  

5.  To remove the flushing fluid, follow step 1 above. 

NOTICE: 

After flushing the pump some residual fluid will remain 
in the pump and piping. 
 

NOTICE: 

Properly dispose of all waste fluids in accordance with 
the appropriate codes and regulations.