
MP PUMPS HTO SERIES
HTO 180 INST ALLATION AND SERVICE INSTRUCTIONS
This bulletin must be read completely before installing, operating, or servicing the pump.
W ARNING:
!
     by hot oil may occur.
If any of the items listed below are violated, serious injury or death from burns caused
DO NOT perform service or maintenance when
the pumping system is pressurized or hot serious injury or death from burns caused by 
hot oil may occur.
DO NOT operate the pump in a manner that it
was not intended to be used.
DO NOT install for use in an open environment
where people are present.
DO NOT install in a rigid piping system that does
not allow the pipe to expand and cause the pump 
to be strained.
DO NOT continue to operate the pumping
system when a know leak exists or the system 
continues to smoke.
DO NOT  continue to operate the pump when
unusual noise or vibration occurs.
DO NOT operate beyond the pressure or
temperature limits stated in the product literature. 
(See Form 9001)
DO NOT allow severe temperature changes to
occur in a short time period within the pumping 
system.
DO NOT mix different types or grades of oil
within the oil system.
DO NOT use an oil that is not a recommended
heat transfer oil by the manufacturer.
DO NOT exceed the maximum oil temperature
rated by the oil manufacturer at the hottest point 
in the pumping system.
DO NOT mount the pump such that high piping
loads exist on the pump flanges.
DO NOT install or use near water where the
pumping system may come into contact with 
water or is splashed by water.
   FORM 3073 (9-04)

MP PUMPS HTO SERIES
OPERA TION AND MAINTENANCE
Thermal oil vapors leaking from a system can be highly 
flammable.
Any system leak should be repaired immediately. 
Do not insulate the pump or system piping with porous
flammable insulation. Fluid may wick, decompose, and 
spontaneously ignite.
Ideal mechanical seal life is 20,000 hours. Reduced seal life 
may be experienced from extreme conditions.
Recommended spare parts and service parts to rebuild the 
HTO-180 are:
HTO 180 ASSEMBLY INSTRUCTIONS
At disassembly, check the impeller and other wear items for 
unusual wear. Replace if necessary .
When servicing the pump, care should be taken that the pump 
has cooled to a sufficient temperature to permit disassembly . 
The product should be drained from the pump  housing and 
disposed in accordance with the fluid manufacturer’s 
recommendations.   Operation personnel should be warned 
to exercise care and utilize eye and skin protection when
servicing the pump.
1. Press the seal seat (part #16) into the seal 
   housing #12.
2. Set the drive sleeve #17 standing up on the 
workbench with the threaded end up. Place the
  seal housing #12 on the sleeve with the seal 
   seat facing up.
3. Lubricate the seal head’s o-ring (part of #16) and
   slide it over the sleeve.
4. Install the snap ring #15 into the groove on the
   sleeve.
5. Set the seal head working height to .25 inches 
by measuring the distance from the snap ring to
   the back of the seal.
6. Tighten the four - 1/8 inch set screws on the seal 
head through the hole on the side of the seal
   housing if applicable.
7. Install the pipe plug (part #13) into the seal
   housing. Use sealant on the threads.
8. Install the three gaskets #9, two graphite 
isolators #10, and o-ring #11 over the drive sleeve 
onto the seal housing.
9. Place the seal housing assembly from step 8 into 
the adaptor #6 and install three capscrews #14 
through the seal housing and into the adaptor. 
Torque the capscrews to 2- ft-lbs. in 5 ft-lbs. 
increments.
10.Apply Loctite onto the drive sleeve threads and 
install the impeller #5 by threading it onto the 
sleeve. Make sure that the impeller shoulders 
against the sleeve.
11. Position the gasket #3 onto the adaptor and install 
the housing #16 to the adaptor using eight 
capscrews #7 and lckwashers #8.
12. Slide the fan clamp #18 onto the sleeve with fan 
blades closest to the seal housing. The pump 
end assembly (Pumpak) is complete.
13. Pumpak assembly to the motor as follows:
1. Place 5/16x5/16x.5 key into the key slot
     of the motor shaft.
2. Slide the Pumpak onto the motor with the
shaft/key indexed to lineup with a slot in 
the pump sleeve.
3. Install and tighten (4) 1/2”-13 capscrews
onto the motor flange with 40 ft-lbs. torque.
4. Reaching through the inlet of the pump
push the impeller back towards the motor 
until it stops up against the carbon isolators.
5. While holding the impeller in this position,
tighten the fasteners of the fan clamp with 
15 ft-lbs. torque.
 6. Rotate impeller to check for contact with 
stationary parts.
7. Install piping.
   8. After wiring the motor, check rotation by 
momentarily applying power and viewing 
the rotation of the fan clamp. Viewed from 
the motor end, the clamp should rotate in a 
clockwise direction.
  -2-

MP PUMPS HTO SERIES
APPLICA TION AND INSTALLA TION INSTRUCTIONS
Application assistance and technical 
information can be obtained by calling 
MP PUMPS at 586-293-8240.
The HTO pump is designed for pumping high 
temperature fluids that are non-corrosive, 
non-volatile, and have good lubricating 
qualities.
INST ALLA TION AND START UP
INSTALLATION
1. The pump must be installed in a horizontal 
shaft position.
2. The housing may be rotated to a horizontal or 
vertical discharge to fit the particular piping 
installation.
3. Rigid and supported piping must be used that 
will not strain the pump housing when 
temperature changes are made during the use of 
the pump.
4. The piping system must be free of foreign 
material and moisture before start up.
5. Pipe thread sealing compound must be used on 
the NPT flanges that is compatible with the fluid 
being pumped and is rated for the temperature 
requirements.
6. The installation should permit adequate 
circulation of air to provide proper cooling of the 
motor and pump seal housing.
7. Do not install in a sealed enclosure or insulate 
the pump adaptor and motor. The motor and/or 
pump seal may fail from excessive heat.
The primary application for use is with heat 
transfer oils.
It is the users’ responsibility to determine the 
pump and product compatibility with the 
materials of construction.
START UP
1. Follow all requirements and recommendations 
from the heat transfer fluid manufacturer, for 
fill, start up, and use.
2. Check for leaks before insulating the piping 
system.
3. Check for proper shaft rotation by jogging the 
power and observing the fan clamp. Rotation 
arrows are provided on pump housing.
4. The seal cavity inside the pump will internally 
vent during the fill and start up.
5. A small amount of oil may leak from the seal 
cavity at the shaft; this is normal for a new 
installation and will stop after approximately 
one hour.
6. Do not allow the pump to run dry, or continue to 
operate the pump when it is noisy, vibrating, or 
leaks are observed. These noticeable signs 
give a warning that something is wrong with the 
equipment and must be investigated to avoid 
possible damage or injury from burns caused 
by hot oil.
8. A good installation will have an enclosure that 
provides adequate air flow of ambient air to the 
motor of the pump.
-3-