Troubleshooting, Danger, Disassembly – relief valve – Viking Pump TSM340.1: SG-10, SG-14 User Manual
Page 9: Assembly – relief valve, Pressure adjustment
SECTION TSM
340.1
ISSUE
D
PAGE 9 OF 11
Before opening any Viking pump liquid
chamber (pumping chamber, reservoir, relief
valve adjusting cap fitting etc.) Be sure:
1. That any pressure in chamber has been
completely vented through suction or
discharge lines or other appropriate
openings or connections.
2. That the driving means (motor, turbine,
engine, etc.) has been “locked out” or made
non- operational so that it cannot be started
while work is being done on pump.
3. That you know what liquid the pump has been
handling and the precautions necessary to
safely handle the liquid. Obtain a material
safety data sheet (MSDS) for the liquid to be
sure these precautions are understood.
Failure to follow above listed precautionary
measures may result in serious injury or death.
DANGER !
TROUBLESHOOTING:
A Viking pump that is properly installed and maintained will
give long satisfactory performance.
If trouble does develop, one of the first steps toward finding
the difficulty is to install a vacuum gauge in the suction line
and a pressure gauge in the discharge line. Readings on
these gauges often give a clue on where to start looking for
trouble.
DISASSEMBLY – RELIEF VALVE:
Mark the valve and head before disassembly to ensure
proper reassembly.
1. Remove the valve cap.
2. Measure and record the length of extension of the
adjusting screw. Refer to
“A” on Figure 4.
3. Loosen the locknut and back out the adjusting screw until
spring pressure is released.
4. Remove the bonnet, spring guide, spring and poppet from
the valve body. Clean and inspect all parts for wear or
damage and replace as necessary.
ASSEMBLY – RELIEF VALVE:
Reverse the procedures outlined under
DISASSEMBLY –
RELIEF VALVE. If the valve is removed for repairs, be sure
to replace in the original position. The relief valve adjusting
screw cap must
always point towards the suction side of
the pump. If the pump rotation is reversed, remove the relief
valve and turn end for end.
PRESSURE ADJUSTMENT:
If a new spring is installed or if pressure setting of pressure
relief valve is to be changed from that which the factory has
set, the following instructions must be carefully followed.
1. Carefully remove valve cap which covers adjusting screw.
Loosen locknut which locks adjusting screw so pressure
setting will not change during operation of pump.
2. Install a pressure gauge in discharge line for actual
adjusting operation.
3. Turn adjusting screw in to increase pressure and out to
decrease pressure.
4. With discharge line closed at point beyond pressure
gauge, gauge will show maximum pressure valve will
allow while pump is in operation.
VACUUM GAUGE - SUCTION PORT:
High vacuum reading would indicate:
1. The suction line is blocked, valve closed, a strainer is
plugged or a pinched suction line.
2. The suction line is too small.
3. The liquid is too viscous to flow through the piping.
4. The lift required is too high.
Low reading would indicate:
1. There may be an air leak in the suction line.
2. The end of the pipe is not in the liquid.
3. The pump is worn.
4. The pump is dry and should be primed.
Fluttery, jumping or erratic reading would indicate:
1. The liquid is vaporizing.
2. Liquid is coming in to the pump in slugs, possibly an air
leak or insufficient liquid above the end of the suction
pipe.
3. Vibration from cavitation, misalignment, or damaged parts.
PRESSURE GAUGE - DISCHARGE PORT:
High reading would indicate:
1. High viscosity and small diameter and/or lengthy
discharge line.
2. A downstream strainer or filter is plugged.
3. The pressure relief valve is set too high.
4. Valve in the discharge line partially closed.
5. Line partially plugged from build up on inside of pump,
solidified product or foreign object.
6. Liquid in the pipe not up to temperature.
Low reading would indicate:
1. Pressure relief valve set too low.
2. Pressure relief valve poppet not seating properly.
3. Pump assembly bolts not torqued to specifications.
4. The bypass around pump partially open.
5. Pump is damaged or worn.
6. The pump has too much internal clearance.