Pressure pumps: 10 things you need to know about them

Sometimes it is necessary to artificially increase the water pressure in the pipeline by using pressurizing pumps, when the pressure exerted by the water column from the tank to the device is insufficient, or when there is a negative slope that eliminates the effects of gravity; This is particularly important when entering water heaters or hoses.

In this note we will see ten characteristics and secrets that every plumber (and user) should know about these pumps.

Booster Pumps: What Every Plumber Should Know About Them

1. Calculate the maximum and minimum pressure

Appliances such as water heaters, purifiers, boilers and others require working in an acceptable pressure range; Just as low pressure prevents its correct operation and can cause failures and breakdowns, excess pressure can be equally damaging and even dangerous.

Check the minimum and maximum service pressure in the devices to be pressurized, and choose those pressurizing pumps that guarantee a service pressure above the minimum but at least 10% below the maximum.

2. Know the direction of water circulation

The pressurizing pumps must be installed according to the flow indicator arrow; it should always be oriented in a totally vertical direction and pointing upwards.

Just as it is important to respect the direction of water circulation, it is necessary that the pump be installed in a position that does not affect the operation of the pressurizing chamber.

Pressurizing pump

3. Know the correct installation procedure

• Always work with the pump disconnected from the electrical power.
• Clean the water tank, install a filter at its outlet and check that there are no leaks or air inlets on the downspout.
• If possible, install a stopcock above the pump discharge, and immediately afterwards a check valve to prevent back water.
• Use threaded unions for the check valve and stopcock. At other points, try using hot melt or solder.
• Verify that the joints between tubes of different materials do not produce galvanic corrosion (an example of this is the union of bronze or copper pipes with other galvanized iron pipes).
• Perform a manual purge before putting the booster pumps into service (see point 8).

4. Place the pump before the appliances

Both to pressurize a water heater or boiler and to supply the toilets of a bathroom or other passive devices, it is important to remember that the pump must always be in the hydraulic circuit first, since, if air enters the circuit, it is preferable that Get to the pump first (which has the ability to self-purge as long as there is positive inlet pressure).

5. Always work with check valves

Check valves work analogously to diodes in an electrical circuit, they allow the passage of water only in one direction.

When positioned correctly after discharge of the pump, these valves prevent the backward flow of the water column, thus ensuring that the pump always works correctly, even when a little air is leaking into the circuit.

These valves should be replaced about once every two years.

retention valves

6. Always use the automatic mode

The pressurizing pumps are prepared to shut down in the event of zero or negative pressure at the inlet; this as long as they are operating in automatic mode. In manual mode the pump will continue to operate even if there is no water in the pipe, with the consequent risk of overheating.

7. Make sure that the electrical installation is completely watertight

As important as the installation of the pump itself is the installation of the electrical control panel. It must be located in an area away from the pressurizing pumps and it must have an adequate degree of tightness (at least it must comply with a degree of protection or IP 55).

Another fundamental aspect is the security of the installation. This must have a differential switch (circuit breaker) sensitive to 30 mA, plus a bipolar thermal switch. It is also necessary that the installation has its proper grounding, correctly measured and functional.

The power cable between the pump and the panel must be of the type workshop, with triple insulation and grounding cable.

It is of special importance that the panel is located in a place where the water does not reach to wet it under any circumstances, and it must also be easily accessible, even if the area of ​​the pumps is flooded.

8. Know how to properly purge

1. To perform this operation, first interrupt the electrical supply to the pump (by cutting the circuit breaker and the thermal switches on the board). Make sure the pump is not receiving electrical voltage at all.
2. Close the stopcock that is located above the discharge (outlet) of the pump, so that the column of water is not lost in the upper pipe.
3. Remove the bleeder plug (usually located on the side of the pump drum) using a spanner of the same size, or a properly adjusted parrot wrench if you do not have another. tool more suitable.
4. Using a thick, flat-head screwdriver, rotate the pump shaft until water begins to flow through the hole in the bleed plug.
5. Once all the air in the downstream pipe has been removed, replace the plug and tighten firmly.
6. Open the stopcock above the pump discharge.
7. Open a tap up the pipe and run the pump briefly in manual mode, until any air that may have been trapped up the pipe is eliminated. Turn off the pump and return it to the automatic mode position.

9. Check installation frequently

The review procedure should be routine, once every 15 days for example, and should not take more than a few minutes.

Start by looking at the inlet and outlet connections of the pump. Inspect them by sight while the pump is running. Observe that there are no losses; even the occasional small droplet could force air into the system.

Threaded joints are normally sealed with Teflon tape, although litharge paste is sometimes used. Avoid using both at the same time as they are not redundant with each other and the litharge paste will end up damaging the Teflon. The recommended is Teflon tape.

Then check the pipe upstream, verifying that there are no leaks, and that the unions do not present the same problem as above.

Check downstream pipe for possible leaks or cracks. If there is a stopcock, make sure it is fully open for the branch that feeds the pump.

Visually check the condition of the pump power cord. It must be dry and undamaged. The insulation should look healthy, without drying out.

10. What to do in case of leaks or constant shutdowns due to the presence of air

Turn off the pump immediately. If you performed several purging processes and air is still entering the pump, it is necessary to perform maintenance on the water inlet pipe, since upstream the check valve prevents the back-up of water or air.