(see Figure 52 APPENDIX A, SUGGESTED PIPING SYSTEM FOR WGI POWER PUMPS)
Supply System Piping Design
- Pump should be located as close to the liquid supply as possible.
- Use full opening gate valves and avoid constricting valves.
- The ideal piping arrangement is short and direct, using no ells. Should ells be required, use 45 degree long radius instead of 90 degree ells.
- If a reducer is required in inlet line between the main line and pump, use an eccentric reducer rather than concentric (with straight portion on top to help avoid air pockets trapped in inlet line).
- Slope line uniformly to pump from liquid supply to avoid air pockets.
- By-pass design should take liquid back to liquid source and not into inlet line.
- Inlet line should be firmly anchored or buried to avoid putting a strain on the pump and help prevent system vibrations from acting directly on the pump.
- For inlet lines leading directly to the pump, select a size line so that the velocity of the liquid will not exceed one foot per second, or one that is two sizes larger than the pump inlet connection, whichever gives the lower line velocity.
- Install a properly sized charging pump in the inlet line as close to the pump as possible.
- Install a full opening gate valve on the inlet line to allow for pump maintenance.
- Inlet PCT (pulsation control tool).
Discharge Piping Design
- The insertion of a pressure relief valve (PRV) of suitably sized for the full pump capacity and set fully open at a pressure above the required operating discharge pressure of the pump, is mandatory for safe operation.
The PRV should be placed in the discharge line, as close as possible to the pump and before any other valves. The PRV outlet should be piped back to the liquid source.
Suggested trial set pressures of pump PRV’s:
Type Pump Recommended Relief Pressure Double acting Duplex Piston pressure rating plus 25% Single acting Triplex Plunger pressure rating plus 10% Single acting Quintuplex Plunger pressure rating plus 10%
- Install a full opening gate valve on the discharge line to allow pump maintenance.
- Install a check valve on discharge line to protect pump from harmonic vibration from other installations on the line.
- Install a properly sized discharge PCT to reduce vibration and piping damage.
- Securely anchor discharge lines.
- When possible, run discharge lines straight for at least ten feet before bending.
- Install a by-pass valve to aid in pump start-up.
8. Use 45 degree long radius ells.
Recommended Safety Devices
- Hi-Lo oil level control & oil temperature gauge.
- High temperature control.
- Oil pressure control.
- Low liquid level control (to control the NPSHA).
- Low discharge pressure shut-down.
- High discharge pressure shut-down.
- Pre/Post lube of force feed power end lubrication system.