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Operating Instructions For TD/TAD4 Dual Fuel Burner

June 13 160 of 165 TD/TAD4 Manual Rev 4

12.8.3

Installation Operation Maintenance

12.8.3.1

Installation

The  DH  Series  can  be  supplied  for  either
flange  or  boss  mounting  to  suit  most
applications.
Pumps  should  be  mounted  with  the  shaft
horizontal, but the pump body may be turned
on  its  axis  to  allow  easier  access  for  pipe
connections etc.
It  is  essential  that  the  pump  and  the  motor
drive shafts are correctly aligned, that there is
no `play` in the drive connector and that there
is no end pressure on either drive shaft.
See  the  pump  and  motor  arrangement
drawing at the bottom of the page.
Check that all joints on the oil supply pipes,
flexible  oil  lines  etc.  are  properly  sealed  and
that  the  oil  supply  temperature  and  pressure
are  correct  (  see  the  relevant  burner  manual
for  guidance  notes  on  oil  installation,
remembering  that  the  maximum  permissible
oil  supply  pressure  to  DH  series  pumps  is  2
bar.
Residual fuel oils should be supplied to the
inlet port of oil burner pumps at temperatures
of:

40ºC for 200 secs R1 ( 13.5 cSt at 80ºC )
65ºC for 960 secs R1 ( 35 cSt at 80ºC )
80ºC for 4000 secs R1 ( 85 cSt at 80ºC )

When  DH  series  pumps  are  used  with
air/steam  atomised  burners  burning  residual
fuel  oils  the  oil  supply  temperatures  can  be
reduced to:

10ºC for 200 secs R1 ( 13.5 cSt at 80ºC )
30ºC for 960 secs R1 ( 35 cSt at 80ºC )

45ºC for 4000 secs R1 ( 85 cSt at 80ºC )

Distillate fuel oils should be supplied to the
pump inlet port at a slight positive pressure.
Where suction lift is required, the Dunphy
technical department should be consulted.
Residual fuel oils should be supplied to the
pump inlet port at a pressure between 1 and 2
bar.

12.8.3.2

Filtration

Filters must be fitted in the oil supply system
to  prevent  foreign  matter  entering  the  pumps
and  possibly  affecting  performance  or
causing physical damage.
All  DH1  fuel  are  supplied  with  internal
filters,  however,  when  pumps  are  used  with
residual fuel oils, it is recommended that this
filter  is  removed  after  approximately  one
weeks  running  when  it  is  certain  that  any
swarf  or  other  foreign  matter  has  been
thoroughly flushed out of the oil supply lines.
DH2 pumps do not have an integral filter.

12.8.3.3

Oil Re-Circulation

When  supplied  for  use  on  heavy  oil
installations  all  `DH`  series  pumps  are  fitted
with a restrictor with a 4mm diameter orifice
fitted  between  the  oil  inlet  and  ring  main
return ports.
This  allows  the  flow  of  oil  to  circulate  from
the ring main system, through the flexible oil
lines and pump and into the ring main return,
effectively  keeping  both  the  pump  and  the
flexible  oil  lines  warm,  eliminating  the  need
for lagging and trace heating.
  The pumps can be fitted with restrictors with
a  larger  orifice  size,  but  care  must  be  taken
when fitting these that the re-circulation does
not depress the ring main capacity as this is a
direct bleed between the flow and return.

12.8.3.4

DH (P) Fuel Pumps ( Light oil)

All `DH` series pumps with the prefix `P` are
fitted  with  a  manifold  on  the  oil  return  port
that  allows  a  flow  of  oil  back  into  the  return
while the burner is `purging`.
This  allows the pump to automatically prime
itself  every  time  the  burner  goes  through  its
starting  cycle  and  eliminates  the  need  for
mechanical

venting.

P U M P

H O U S I N G C O V E R

A N D S C R E W S

C O U P L I N G A N D S E T S C R E W S
C O U P L I N G I N S E T

H O U S I N G

P U M P F L A N G E A D A P T O R

A N D S C R E W S

P A R A L L E L K E Y

D R I V E M O T O R

TYP ICAL ARRANGEMENT OF P UMP, MOTOR AND DRIVE COUP LING