What is a pressure tank?

What this means for your home project

1. Record whether the well pump starts repeatedly or the water pressure stays low; include those observations in the service request. Source: Amtrol, read 2026-11-04.
2. Look at the tank’s pipe connections: Nebraska Extension describes a bladder tank with one pipe serving as both inlet and outlet. Source: University of Nebraska–Lincoln Extension, read 2026-11-04.
3. Request a written replacement recommendation naming the tank type, pump type, water use and well yield used to choose it. Source: University of Nebraska–Lincoln Extension, read 2026-11-04.
4. If the pump starts and stops frequently, request a system inspection to identify the cause before deciding on replacement. Source: Amtrol, read 2026-11-04.

What do I set my well tank precharge to?

For a conventional Amtrol tank, ask the installer to document specification 2 PSI below pump cut-in, meaning the pressure that starts refilling. “The well tank precharge should be set to 2 PSI below the cutin of your pressure switch setting.” Source: Amtrol, read 2026-11-04. “All precharge adjustments need to be made when the vessel is completely empty of water.” Source: Amtrol, read 2026-11-04.

How do I winterize my well tank?

For an Amtrol well system’s seasonal shutdown, request a draining plan that includes connected pipework and the power-disconnection sequence in the manufacturer’s instructions. “In order to winterize a well tank, you will need to completely drain the tank and adjacent piping of water.” Source: Amtrol, read 2026-11-04. “Disconnect the power to your well pump, then open a drain fixture until the water pressure reads 0 PSI.” Source: Amtrol, read 2026-11-04.

How can I tell if my tank needs to be replaced?

For an Amtrol well tank, note pressure changes and pump behavior for the service visit; the manufacturer describes replacement as a possibility after an air-pressure assessment. “Symptoms of a tank that needs replacement are rapid cycling of your pump, or low pressure in your system.” Source: Amtrol, read 2026-11-04. “If your tank has low or no air, your tank may need to be replaced.” Source: Amtrol, read 2026-11-04.

Why is my pump cycling on and off frequently?

Ask for a diagnosis before ordering equipment, because Amtrol’s pump-system guidance identifies several possible causes for repeated starts and stops. “Frequent cycling may indicate an undersized tank, loss of air charge, incorrect pressure switch settings, or increase in system demand.” Source: Amtrol, read 2026-11-04. “A system inspection would be recommended to determine root cause.” Source: Amtrol, read 2026-11-04.

How do I know what size of tank I need?

For a replacement quote, request the proposed capacity alongside the pump’s output and the well’s yield so the selection can be reviewed. “The type of pressure tank is determined by the type of water pump, the amount of water used, and the water yield from a well.” Source: University of Nebraska–Lincoln Extension, read 2026-11-04. “Multiply the flow rate by four to determine the size of a diaphragm or bladder tank.” Source: University of Nebraska–Lincoln Extension, read 2026-11-04. “For example, a 9-gpm pump would require a 36-gallon storage tank.” Source: University of Nebraska–Lincoln Extension, read 2026-11-04.

Can I use a variable speed drive to control my water pressure?

Where the well can keep up with demand, discuss a controller that varies pump speed as an alternative to conventional on-and-off operation. “If well yield isn't a concern, then it might be possible to use a variable speed pumping system and controller to help maintain water pressure.” Source: Private Well Class / Illinois State Water Survey, read 2026-11-04. “The pump maintains the pressure in the system and changes speeds to match the changing pressure requirements.” Source: Private Well Class / Illinois State Water Survey, read 2026-11-04. “For these installations, the pressure tank is only a few gallons in size and helps keep the pressure constant on pump start-up.” Source: Private Well Class / Illinois State Water Survey, read 2026-11-04.

What causes my pump to turn on?

For a conventional private well, note the gauge reading when refilling begins and compare that observation with the Private Well Class guidance. “When the pressure in the line drops below the low-end preset level, generally 20 to 40 PSI, it engages automatic controls and preset gauges like the pressure switch in Figure 1.” Source: Private Well Class / Illinois State Water Survey, read 2026-11-04.

How have pressure tanks changed over time?

Before selecting a replacement, compare the pipe connections and whether a flexible internal barrier separates the water from the air cushion. “This type of tank has a separate inlet and outlet, and requires an air volume control to maintain the appropriate air-to-water volume in the tank.” Source: University of Nebraska–Lincoln Extension, read 2026-11-04. “Bladder pressure tanks have a single pipe that serves as both an inlet and an outlet.” Source: University of Nebraska–Lincoln Extension, read 2026-11-04. “As the name implies, a bladder tank contains a flexible bladder that permanently separates the air and water.” Source: Private Well Class / Illinois State Water Survey, read 2026-11-04. “The tanks do not have a bladder and so air is in direct contact with the water.” Source: Connecticut Department of Public Health, read 2026-11-04.

Sources

• G2152: Private Drinking Water Wells: The Distribution System — University of Nebraska–Lincoln Extension; read 2026-11-04.
• How does my private well pressure tank work? — Private Well Class / Illinois State Water Survey; read 2026-11-04.
• Hydropneumatic Tank Assessment — Connecticut Department of Public Health; read 2026-11-04.
• Well Systems FAQs — Amtrol; read 2026-11-04.
• ASME Tank Support: Pump Systems — Amtrol; read 2026-11-04.