Geothermal Alliance of Illinois Non-Pressurized Flow Centers

Geothermal Alliance of Illinois Non-Pressurized Flow Centers

Commonly referred to as: Flowcenters Atmospheric Pumps Pump Station Flow Station Zero Pressure Pump Source Pump Pumps

Wrongly referred to as: Open System Non-pressurized flow centers are NOT open pumping systems (We will discus this in detail a little later)

Where did it come from? Non-pressurized systems were invented by an experienced geothermal installer that was fed up with the issues related to pressurized pumping systems. So an innovative pumping concept was built and put to the test.

Dallas Warnke, the founder of B&D MFG, INC quickly realized the market opportunity of manufacturing his flowcenter had great potential In 1992 the flowcenter went to market with early production rates of 2-300 units per year employing 5-7 people

Currently B&D has a production rate of 2-300 flowcenters* per week and employs 30-40 people *GT/QT flowcenters

How does it work? First lets look at the type of pump that is used in the flowcenter The very popular and durable Grundfos 26-99/26-116

The 26-99 is a wet-rotor pump which means it is water lubricated The 26-99 is an in-line pump which means it s a pressure pump YES it needs pressure to pump water BUT this is a Non-Pressurized system right???

The question is how much pressure does an in-line pump need?? Many miss-guided people will quickly suggest the pump needs 20,30,40 PSI or more to pump water It really doesn t need a given amount of system pressure All it needs is a small amount of STATIC PRESSURE

As you look through the product information on any in-line pump it will show the required Static Pressure **This is different than gauge pressure or absolute pressure**

This particular pump is rated at 140 f at 1.4 psi of required static pressure. As the temperature goes down so does the required static pressure. That is because as water gets cooler it becomes more dense. So for a geothermal system temperature range of 20-90 f the required static pressure is.5 -.8 psi.

Static Pressure is Defined as: The pressure exerted by a still liquid or gas. How is Static Pressure Measured or Calculated? Simple rule of thumb:

Simple rule of thumb: For every one foot of water You will have 1/2 psi of static pressure OR.042 psi per inch of water column

31 35 Non-Pressurized Flowcenters Simple rule of thumb: 31 x.042 = 1.30 psi Well above the static requirement for all inline wet rotor pumps.

So lets bring this all together and recap: The 26-99 is a wet rotor inline pump The 26-99 requires.5 -.8 psi of static pressure to pump water The flowcenter canister provides 1.3 psi of static The non-pressurized system does not require and cannot be charged to an established system pressure

A few more things to keep in mind: Water that is pumped out of the canister is retuned at the same rate (gpm flow) A check valve is located beneath the pump(s) The canister is a reservoir that constantly keeps water in the volute of the pumps

Water level remains constant A check valve located beneath the pump

So because the fluid level is always above the pumps They will always have water to pump This will never allow the pump(s) to cavitate This is referred to as a flooded suction

Non-Pressurized verses Pressurized The never ending war: There are (3) major fundamental differences between Non-Pressurized and Pressurized pumping systems

Non-Pressurized verses Pressurized 1. The obvious Pressure 2. System Expansion 3. Air Relief

Non-Pressurized verses Pressurized Pressure: There is no pressure to be maintained in a non-pressurized system. This is the most common call back for a pressurized system is loss of pressure. What causes loss of system pressure?

Non-Pressurized verses Pressurized System Expansion: The Flowcenter acts as an expansion devise during temperature fluctuation. Pressurized system DOES NOT have a expansion devise. Expansion and contraction is a catalyst for dissolved air to come out of solution.

Non-Pressurized verses Pressurized Air Relief: The Flowcenter canister allows entrapped air to be relived out of the water. Pressurized systems do not have air relief devises. Trapped air in a geothermal system can have catastrophic results

Non-Pressurized verses Pressurized Benefits/Sales Points: No Pressure to maintain Automatic air relief Expansion chamber Other benefits: Fluid access Measureable flowrates Pump maintenance Loop field purging***

Non-Pressurized vs Pressurized Loop Field Fill, Flush and Purge: There are (2) ways to header loop field piping. Interior Valued Manifold- Outside Buried Header- Neither way is right or wrong, the difference is the required tools to properly purge the loop field piping.

Pump Selection ( a very brief introduction): Every system has a required flow rate and a corresponding pressure drop + = GPM @ Feet of head

Pump Selection ( a very brief introduction): Grundfos 26-99 & 26-116

Questions?