Booster Pump Issues

[jnaas2]

Your pump is pulling more water then the city water supply can deliver, thats why its clogging your filter and and sucking the water out of your filter. The proper installation of a booster pump requires a storage tank to deliver more water to the pump when the city water supply cant keep up, and the pump is suppose to have a pressure switch that shuts the pump off to keep it from pulling a vacuum on the city water supply

The reason for this is if it pulls a vacuum on the water line it can pull in contaminants into the water supply,

[LazyPup]

Unless they are using a fire truck for a boost pump, the boost pump cannot pull more water than what can be supplied by the municipal main. The size of the line from the municipal maina to the structure does not limit the volume of flow. As demand increases the velocity of flow will increase proportional to the demand. The problem is that as a liquid passes through a line there is a friction between the liquid and the inner walls of the pipe. As the velocity of flow increases the "Friction Head Loss" will increase exponentially.

By example: In a 3/4" pipe,

If the demand is 1gpm the velocity of flow is 0.49ft/sec and the pressure loss is 0.07psi/00ft

If the demand is increased to 2gpm Vel. of flow = 0.99ft/sec and FHL is 0.24psi/100ft

If the demand is increased to 5gpm Vel if flow = 2.46ft/sec and FHL is 2.433psi/100ft

If the demand was increased to 30gpm the Vel.Flow would =14.78ft/sec and the FHL would be 36.64psi/100ft.

As you can see, when the demand was increased 30x the line could still carry the water but while demand increased 30x the pressure loss increased 523x.

In addition to a substantial pressure loss, the increase in velocity and friction also causes an increase in pipe line wall erosion. In order to maintain proper pressure and minimize pipe wall erosion the codes mandate that when determining the line size the velocity of flow in a copper line may not exceed 8ft/sec or 12ft/sec in a plastic line.

To properly size a line the code requires that we first make a list of all fixtures that are connected to that line, then check a code table to determine the individual demand for each fixture and compute the total load.

We then have to measure the total developed length of pipe from the source, which in the case of the main supply line is the municipal main or home well pump to the furthest fixture and consult a "Friction Head Loss Table" to select the proper size of line to insure the velocity of flow does not exceed the code mandates. We must then have the "Static Head Pressure" of the municipal main, and once we know the volume and length of line we can compute the "Friction Head Loss". If the Static Head Pressure less the Friction head loss results in a pressure at the main water shutoff which is less than the code minimum of 40psi we first check to see if we could obtain the correct pressure by increasing the line size (thus decreasing friction head loss).

If we cannot achieve the code minimum pressure we then install a "Boost Pump" but that boost pump MUST BE installed immediately after the main water shutoff valve, and before the line feeds any fixture or water treatment equipment.

The reason your tank is drawing down is because the pressure and velocity of flow from the municipal main cannot supply water fast enough to overcome the additional friction of the sand in your filter. If the boost pump is installed before the filter the problem will be solved.

[rmw]

I think we are getting into detail and missing the problem.

1 install a expansion tank on hot water heater cold water inlet.

2 move booster pump to before water filter as soon as it come into house from city supply.