Buffer Tank CGAM

Issue:

Are there details on the CGAM Buffer Tank?

Resolution:

The Buffer (water) Tank is factory installed on the chiller for easy installation at the building site. The purpose of the tank is to increase the chilled water loop inertia which is necessary with short water loops. A high inertia circuit reduces the compressor's cycling and allow for more precise leaving water temperature control.

When the buffer tank option is selected it will increase the overall footprint (unit length) of the 20 - 70 nominal ton chillers only. This is due to the buffer tank being installed on the opposite end of the chiller's control panel.

The 80 - 130 nominal ton chillers unit length will not be affected because the buffer tank is located underneath the condenser section and is contained within the base frame.

The tanks do not have internal baffles.
The tank in 80 to 130 models do have a long tube to make sure we are pulling from the opposite side as we are filling from.

For 20 to 70 sizes, there are two vertical tanks connected at the top with a cross over tube. One tank fills with water from the bottom and then water passes through the cross over tube in the top to be pulled from the bottom of the second tank.

Guide Spec verbiage

The tank is engineered for continuous flow and the construction is welded steel; it is powder coated, fully insulated and designed with freeze protection down to -20F (-29C). It needs to be powered by a dedicated power supply which is field provided 120V power.  It is rated with a waterside working pressure of 150 psig and tested at 225 psig. Water connections are groove piped.

Buffer tanks made available in Job Center with December 14, 2012 replication.

Air separators are not included. Air separators are typically installed at the highest point (in elevation) for a chilled water piping loop. Some CGAM may meet this, while many others would not.

Some specifications call for inlet/suction line diffusers for pumps, and we do not add these to our pump package.

Butterfly Valve (3) is a Bray Series 30 valve.  See attached drawing.

Expansion Tank Size (it is a bladder type tank):

When the chiller is configured with a buffer tank the return water from the load enters the top water connection at the end of the chiller which is the inlet to the buffer tank. The return water is then routed to the pump(s). Continuing thru the pump(s) the return water then enters the BPHE and exits the bottom water connection located at the end of the chiller. See BufferTank.pptx attachment below for reference.

See Do you have any details on the pump package? for a schematic on where the buffer tank is located.

The buffer tank for 20 to 70 ton CGAM sizes, does not need to be supported separately. It hangs on the back of the chiller.

Notes:

We do not offer a design special to increase the volume of the buffer tank. Buffer tank volumes are fixed based on nominal size and can be found in the information links referenced above.

We do not offer a design special for the buffer tank and expansion tank without the pumps - Can I get the buffer tank and expansion tank be ordered without the pumps? 

Buffer Tank inlet and outlet water connection sizes can be different diameters on certain nominal sizes. See attachment below for reference.

See Buffer and Expansion Tank CGAM for additional details and pictures

Changes:

Other Question/Problem/Cause Statements:

• Are there details on the CGAM Buffer Tank?
• Do we have guide specs on the Buffer Tank?
• Do we have an option to increase the volume of the buffer tank?
• What is the volume of the buffer tank?
• Does the buffer tank option extend the footprint?
• Is the buffer tank installed underneath the chiller condensing section?
• Where is the buffer tank located on the chiller?

Facts:

• CGAM Buffer Tank with Pump Package
• Air-Cooled Chiller (Pueblo) (CGAM 20-130 Ton)