Tank overflow 'D' is to prevent liquid level rising in pump body and damaging the motor. The lower lip of overflows 'D' should not to move than 1/2" above center of pump overflow. Isolation valve for scaling the tank during maintenance not essential for efficient working of the pump.

A vertical suction pipe with non-return valve with entering top of tank may be used when liquid is free from suspended solids

INSTALLATION 1

1. Fully open valve 'A'
2. Allow level of liquid to rise in supply tank up to overflow 'D' level
3. Close valve 'B'
4. Start pump
5. Open valve 'B' gradually for required flow
   

INSTALLATION 2

1. Close valves 'A' and 'B'
2. Open valve 'D' and leave running until liquid flows out of 'C'
3. Start pump and immediately open valve 'A' fully
4. Close valve 'D'
5. Open valve 'B' gradually for required flow.

INSTALLATION 3

1. Close valves 'A' and 'B'
2. Open valve 'D'
3. Fill priming vessel to overflow 'C'
4. Start pump
5. Open valves 'A'
6. Close valve 'D' and open valve 'B' for flow required

INSTALLATION 4

1. Close valve 'A' and 'B'
2. Fill priming vessel
3. Start pump
4. Open valve 'A' gradually until fully open
5. Open valve 'B' gradually for required flow

INSTALLATION & OPERATION

1. Where Low Level priming is not required

2. Where Low Level priming is required.
   

3. Where priming at all levels is required.
   

4. Where priming at all levels is required without re-circulation.
   

5. For deep variable head storage tanks or where suction lifts must be hopt to minimum.
   

All installation must have the overflow from the pump to the supply or priming vessel:-

• Straight
  
• Have no restriction (valves etc.)
  
• Stop down -1 in 20 or more
  
• Preferably 12" long maximum
  
• Valves 'A' to be of the free flow type.
  

INSTALLATION 5

This installation is basically scheme 1 but level in supply tank is regulated by a mechanical or electrical flow control valve.
Installation for deep variable head storage tanks, or where suction lifts must be kept to a minimum.