Accessories

Accessories

Pressure Tank

Water is almost never pumped directly from the well into the household piping system.

Instead it flows from the pump to a storage tank.

The tank has a cushion of air which is compressed as water flows, thereby keeping the system under pressure.

Air Controls

Air is partially soluble in water.

Hence air in a pressure tank would gradually dissolve, "waterlogging" the tank, unless precautions are taken.

There are three methods of accomplishing this control of air in the pressure tank.

Air Volume Control

This is a valve which fits directly on the pressure tank.

Depending on the water level and system pressure, this device either:

Bleeds air from the tank

Allows air to enter it

Tank Float

A second device prevents tank air from being absorbed by the water simply by separating the two.

This device is a circular float which rides on the water in the tank.

Some designs have a special edge which "wipes" the tank walls, thereby improving the seal.

Even with such designs, some air is dissolved over a period of time.

Hence, tanks equipped with floats must be recharged every few years.

Diaphragm Tanks

A third approach involves tanks equipped with a flexible diaphragm which is permanently sealed to the tank.

As the water level rises and falls in the tank:

The air chamber (separated by the diaphragm) contracts and expands accordingly

Pressure Switch

Water systems are normally designed so that:

The pump starts when pressure falls to a given level (usually 20 or 30 psi)

The pump runs until pressure increases a given increment (generally 20 psi)

The device controlling this on-off action is a pressure switch.

Example settings:

20-40 psi (starts at 20, stops at 40)

30-50 psi

40-60 psi

Pressure Gauge

It is often desirable to monitor operating pressure:

Jet pumps: gauge mounted on unit

Submersibles: gauge located in surface piping

Relief Valve

Many pumps can deliver high-pressure surges.

To protect the system, relief valves:

Open at predetermined pressure

Prevent damage from pressure spikes

Liquid Level Control

If a submersible pumps a well dry, motor damage may occur.

A liquid level control:

Senses critically low water levels

Automatically shuts off pump

Foot Valve

For jet pumps to retain prime, water must remain in drop pipe after shutdown.

A foot valve is:

A check valve at drop pipe end (shallow-well)

Mounted on ejector (deep-well)

Well Seal

Prevents contamination where casing emerges from ground.

Consists of:

Two steel plates

Soft rubber disk between them

When tightened:

Rubber expands

Forms waterproof seal between casing and drop pipe

Pitless Adapter

Provides sanitary underground connection:

Well casing extends above ground

Piping connects below grade

Lightning Arrester

Protects from electrical damage during storms:

Normally conducts electricity

Blocks high-voltage surges (>500V)

Installed across power lines