MECHANICAL SHAFT SEALS
Mechanical seals have two polished faces which run against one another forming a barrier
preventing solution from leaking. A small quantity of liquid crosses the faces and is necessary
to lubricate and remove heat from the seal faces. The two most common causes of seal failure
are:
1)
Abrasive Wear
- The carbon seal face is scratched by harder material crossing the face. Damage
to the seal by harder materials can be caused by abrasive solution materials, rust or corrosion
near the seal, precipitates which come out of solution when heated, and residue between the
seal faces when a pump is shut off and not flushed out. This type of seal failure can be minimized
by flushing the pump with water after use and storing the pump filled with antifreeze to prevent
corrosion and freezing.
Note: In tough applications where the standard carbon seal face is scratched or quickly worn,
the
BAC-7SC
seal with extra hard silicon carbide faces is recommended.
2)
Thermal Shock
- The seal face is cracked by cool liquid contacting a hot seal. There is no
liquid to lubricate or remove heat from the seal faces when a pump runs dry. The seal heats up
rapidly to a temperature that causes damage to the seal components. The resulting thermal shock
creates radial cracks in the white ceramic face and the heat may melt rubber components.
Consult Ace Product Update 2- Mechanical Seals for additional information.
PRESSURE COMPENSATING CLOSED CENTER SYSTEM
OPEN CENTER SYSTEM
Regulate oil flow by using a
RESTRICTOR ORIFICE
. (Do not use flow limiter.)
Setup Instructions:
1. Install restrictor orifice insert inside the adapter/restrictor body
in the motor inlet port (marked
I
).
2. Close motor needle valve: loosen jam nut, screw needle valve
clockwise until seated, and lock jam nut. (factory setting)
3. Set “Rabbit/Turtle” flow control to “Turtle”.
4. Move hydraulic lever to the “Lower/Retract” position to start
pump.
5. Adjust “Rabbit /Turtle” flow control and sprayer agitation valve
to get desired spraying pressure.
Restrictor Orifice
Insert
Select motor size closest to tractor’s hydraulic system capacity. Regulate oil flow with motor
NEEDLE VALVE
. (Do not use restrictor orifice or flow limiter.)
Setup Instructions:
1. Shut off sprayer boom and agitation valves.
2.
200N
- Loosen jam nut on motor and back out needle valve 3
or 4 turns counter clockwise.
300A
- Remove hex cap from side of motor and back out needle
valve 3 or 4 turns counter clockwise.
3. Set tractor throttle to sprayer operating speed.
4. Move hydraulic lever to “Lower/Retract” position to start pump.
5. Screw needle valve clockwise until sprayer shut-off pressure
is below maximum shown in
SHUT-OFF PRESSURE
section
on previous page and lock jam nut or reinstall hex cap.
6. Open the sprayer agitation valve to get desired spraying pressure.
Needle Valve
Adjustment
5