Amtrol 600 LBC User Manual

The AMTROL

®

 expansion tank may be placed in any convenient position 

within the mechanical room (or building). If multiple tanks are installed, 

they should all be on the same level. 

Unlike a conventional tank, the EXTROL

®

 sealed air cushion does not 

require replenishment so DO NOT connect to an air separator or other air 

collection device. 
As with any expansion tank, it is recommended that the EXTROL

®

 be 

connected to the suction side of the pump. This will prevent the pump 

head from becoming subtractive which may result in entry of air and vapor 

formation at high points in the system. 
By connecting the EXTROL

®

 on the boiler return, displacement of coolest 

system water into tank is ensured reducing energy waste. 
Low pressure drop components such as air separators and boilers may be 

placed between point of connection and pump suction if desired. System 

design will dictate the feasibility of this.
Natural convection losses and the entry of air into tanks are eliminated by 

connection to the side or underside of main pipe. The piping should be pitched 

up and away from the EXTROL

®

 to eliminate any potential air traps.

1.  

Note location of system connection, air charge valve and drain 

connection on tank.

2.  Remove the plug or pipe cap from the system connection.
3.  Remove the 1 1/2” NPT plug covering the air charge valve.
4.  Before making any connection to the tank, check the tank and air charge 

(use an accurate pressure gauge). The air pressure must be equal to 

the minimum system pressure at the tank location.

5.  After making sure the air charge is correct, replace the 1 1/2” plug over 

the air valve.

6.   The  EXTROL

®

 may now be piped to the system (use the suggested 

EXTROL

®

 piping diagrams on the next page).

7.  Using the table below, select appropriate pipe size. Connection to 

each EXTROL

®

 must have a lock shield gate valve and union to allow 

isolation and removal if required. Make up and fill valves, whether 

manual or automatic, should be tied into the connecting line. This will 

ensure that pump operation will not affect valve operation. 

Maximum Operating Pressure: As stamped on nameplate
Maximum Operating Temperature: 240 °F
Minimum Operating Temperature: 35°F (non-glycol application)
If unit is being installed in a glycol system where minimum temperatures 

fall below 35°F, contact the AMTROL technical service department at 

(401) 535-1216.

1.  Check the expansion tank pre-charge before the system is filled with 

water. The charge is 12 psig unless noted otherwise on the tank label. 

Check to make sure this is the correct pre-charge pressure specified 

for the system.

2.  If the tank pre-charge pressure needs to be changed on a dry system 

follow the following procedure:

  a.  

Check the expansion tank air pressures at the pre-charge 

connection with an accurate tire type pressure gauge. The 

pre-charge connection is the same kind of connection found on 

automobile tires.

  b.  If the pressure is low, charge the tank with nitrogen gas or with 

oil free compressed air. Check the pressure frequently during this 

process as you would when filling a tire with air.

3.  If, after the system has been filled with water and operating, it is 

found that the expansion tank pre-charge must be changed use the 

following procedure:

  a.  Turn off the heat source and allow the system water to cool to 

ambient temperature.

  b. Close the lock-shield valve in the tank-to-system piping.  
   c. Open the drain valve to empty the water from the tank.
  d. Check the tank air pressure at the pre-charge connection with an  

    accurate tire type air gauge. 
  e. Refer to 2b above.
  f.  Close the drain valve, open the lock-shield valve and turn on the  

    heat source.
  g. Relock the lock-shield valve.

 2,000 

1/2” 

3/4” 

1”

 

4,000 

3/4” 

1” 

1 1/4”

 

8,000 

1” 

1 1/4” 

1 1/2”

 

12,000 

1 1/4” 

1 1/2” 

2”

 

16,000 

1 1/4” 

2” 

2 1/2”

 

20,000 

1 1/2” 

2” 

2 1/2”