Rotech ANSI LTR, Инструкция по установке, эксплуатации и обслуживанию

Страница: 12 / 52

08
OPERATION
Priming Of Pump
Centrifugal pump will require to prime to operate
satisfactorily. Do not try to prime pump when operating
and DO NOT under any circumstances operate the pump
without being completely primed. Some of the most
common methods of priming are flooded suction, foot
valve in suction line, ejector (steam, water, or air operat-
ed), and vacuum pump.
With Flooded Suction:
1. Slowly open the gate valve in the suction line.
2. Remove the air vent in the top of the pump casing to
release entrained air.
3. Close the air vent once liquid starts to flow out of it.
With Foot Valve In Suction Line:
1. Open air vent on pump casing.
2. The pump and suction line must be filled with the
liquid being pumped. It is recommended to fill the
discharge pipe several feet above the pump discharge.
3. After filling pipe and pump close air vent.
4. The pump will remain primed unless the foot valve
leaks or if the liquid is contaminated & does not allow foot
valve to close tight.
With an Ejector:
1. Mount ejector at the highest point in the impeller
housing to ensure removal of all the air in the casing &
suction pipe.
2. Operate ejector with gate valve in discharge line
closed.
3. Operate until ejector discharges a full steady flow of
liquid.
4. On pumps using packing it may be necessary to
tighten packing gland to prevent pulling of air through
shaft clearances. After pump is primed properly loosen
gland to achieve a slight trickle of liquid through stuffing
box.
With a Vacuum Pump:
1. Mount vacuum pump at the highest point in the
impeller housing to ensure removal of all the air in the
casing and suction pipe.
2. Gate valve in discharge line must be closed.
3. After pump is primed, valves between vacuum pump &
Rotech pump must be closed.
4. On pumps using packing it may be necessary to
tighten packing gland to prevent pulling of air through
shaft clearances. After pump is primed properly loosen
gland to achieve a slight trickle of liquid through stuffing
box.
Operating pump dry will cause damage to mechanical
seal and may cause rotating parts to seize.
! WARNING !
PREPARATION FOR START-UP
Check Rotation
1. Please check wiring of motor as per motor manufac-
ture’s specifications & according to local regulations.
2. Lock out power to driver
3. Disconnect motor/pump shaft coupling to prevent dry
operation of the pump and reverse rotation.
4. Make sure everyone is clear. Jog motor starter, pump
must rotate clockwise when viewing from the driving end
looking over the motor. Direction arrows are cast in
impeller housings.
Check Impeller Clearance
Before starting pump the impeller clearance must be
checked. The pump efficiency is maintained when the
proper impeller clearance is set. When pumping liquids
under 200°F (93°C), the impeller front clearance for the
STR, MTR, and LTR is between .010" and .015". If the
impeller front clearance is not set between the above
values significant performance degradation will result.
When pumping liquids above 200°F (93°C) the front
impeller clearance when cold must be set per Table 2.
This is necessary to allow for differential expansion due to
the higher operating temperature. See the Maintenance
section for correct impeller adjustment procedure.
TABLE 2: IMPELLER CLEARANCES
Coupling Of Pump And Motor
1. Lock out power to motor to prevent accidental rotation
& physical injury.
2. Install and lubricate coupling per manufacturer’s
instructions.
3. Install coupling guard (see Appendix 3 Coupling Guard
Installation instructions).
Cold Temperature Clearances For
Service Temperature Clearance
Up to 200°F (93°C) .010" - .015"
200°F to 250°F (121°C) .012" - .017"
250°F to 300°F (149°C) .014" - .019"
300°F to 350°F (177°C) .016" - .021"
350°F to 400°F (204°C) .018" - .023"