10
177-999H
T100 Series Medium - Installation (Cont’d)
Adjust the pressure relief valve to no more than 10% over the
maximum working pressure of the pump.
Route the bypass line to the supply tank. See the diagram showing
a typical installation at the beginning of the Installation Section.
If the pump may be run for a long time with the discharge closed
and fluid bypassing, install a thermal protector in the bypass line
(to prevent severe temperature buildup in the bypassed fluid).
CAUTION:
Never
install shutoff valves in the bypass line
or between the pump and pressure relief valve.
Install a pressure gauge in the discharge line.
Vacuum at Outlet.
Do not allow a vacuum at the pump outlet
during shutdown. A vacuum can damage the diaphragm at start-up.
If there is a vacuum at the pump outlet, allow atmospheric pressure
at the outlet for 30 minutes before starting. Wanner Engineering
recommends installing an outlet check valve with a 65 psi cracking
pressure to prevent a vacuum condition during shutdown.
Oil Level Monitoring.
Oil level is sensed by the back cover
float switch (48) and can be used to control the pump system
operation.
Before Initial Start-Up
Before you start the pump, be sure that:
• Pump is stored at a temperature between 40-180 F (4.4-82.2 C)
for a minimum of 24 hours before start up.
• All shutoff valves are open, and the pump has an adequate
supply of fluid.
• All connections are tight.
• The oil level is within the marking on the dipstick. Add oil as
needed. The oil level can also be viewed through the sight
glass (42) on the back cover (12). The oil level is OK when
the float (48) is in the middle of the sight glass.
• Connect the float switch (if used). See Float Switch Section.
• Test the float switch by removing the side port plug (50) and
manipulating the float up and down using a suitable tool
(screwdriver). Reinstall side port plug.
CAUTION: Take care not to drop tool inside pump.
• The relief valve on the pump outlet is adjusted so the pump
starts under minimum pressure.
• All shaft couplings or drive pulleys have adequate safety
guards.
Initial Start-Up
1. Pump must be at or above 40 F (4.4 C) for 24 hours prior to
starting.
2. Open the bypass line start-up and capacity-control valve so the
pump may be started against negligible discharge pressure.
3. Turn on power to the pump motor.
4. Check the inlet pressure or vacuum. To maintain maximum
flow, inlet vacuum must not exceed 7 in. Hg at 70° F (180 mm
Hg at 21° C). Inlet pressure must not exceed 500 psi (34 bar).
5. Listen for any erratic noise, and look for unsteady flow. If the
pump does not clear, refer to the Troubleshooting Section.
6. If the system has an air lock and the pump fails to prime:
a. Turn off the power.
b. Remove the pressure gauge from the tee fitting at the
pump outlet (see installation diagram).
• Use at least 4 in. (102 mm) I.D. inlet hose
• Use
suction
hose (low-pressure hose, non collapsing) for
the inlet lines
• Minimize fittings (elbows, valves, tees, etc.)
•
Use a suction stabilizer on the inlet.
Net Positive Suction Head
NPSHa must be equal to or greater than NPSHr. If not, the
pressure in the pump inlet will be lower than the vapor pressure
of the fluid — and cavitation will occur.
Calculating the NPSHa
Use the following formula to calculate the NPSHa:
NPSHa = Pt + Hz - Hf - Ha - Pvp
where:
Pt = Atmospheric pressure
Hz = Vertical distance from liquid surface to pump center line
(if liquid is below pump center line, the Hz is negative)
Hf = Friction losses in suction piping
Ha = Acceleration head at pump suction
Pvp = Absolute vapor pressure of liquid at pumping temperature
Notes:
• In good practice, NPSHa should be 2 ft greater than NPSHr
• All values must be expressed in feet of liquid
Atmospheric Pressure at Various Altitudes
Altitude
Pressure
Altitude
Pressure
(ft)
(ft of H
2
O)
(ft)
(ft of H
2
O)
0
33.9
1500
32.1
500
33.3
2000
31.5
1000
32.8
5000
28.2
Discharge Piping
Hose and Routing
Use the shortest, most-direct route for the discharge line.
Select pipe or hose with a
working pressure
rating of at least
1.5 times the maximum system pressure. EXAMPLE: Select
a 1500 psi W.P.-rated hose for systems to be operated at 1000
psi-gauge pressure.
Use flexible hose between the pump and rigid piping to absorb
vibration, expansion or contraction.
Support the pump and piping independently. Size the discharge line
so that the velocity of the fluid will be 3-10 ft/sec (1-3 m/sec):
For pipe in inches: Velocity (ft/sec) = 0.408 x GPM/Pipe ID
2
For pipe in mm: Velocity (m/sec) = 21.2 x LPM/Pipe ID
2
Pressure Relief
Install a pressure relief valve in the discharge line.
Bypass
pressure must not exceed the pressure limit of the pump.
Size the relief valve so that, when fully open, it will be large
enough to relieve the full capacity of the pump without
overpressurizing the pump.
Locate the valve as close to the pump as possible and ahead
of any other valves.