When it comes to picking out the correct pressure tank necessary for your situation, the size of the tank will make or break the effectiveness of the product. If you fail to invest in the correct size pressure tank, you can short cycle your pump. Due to the pump turning on and off too often, it will then suffer premature failure as it builds up excessive heat. In order to avoid this from happening, there are a number of factors that you should consider in determining the correct pressure tank size:

  1. Gallons Per Minute
    Recognizing how many gallons per minute your pump produces is crucial when choosing the pressure tank size. This factor goes hand-in-hand with the horsepower of the motor.
  2. Horsepower of the motor
    In relation to the pump industry standard, it is recommended that all 1.5hp motors and smaller have a run time of at least one minute. Anything over 1.5hp should ideally be a minimum of two minutes. The longer cycle time helps keep the motor cool, which will increase the lifespan of the motor.
  3. Pressure setting
    How much water is stored in the tank is characterized by its pressure setting. When it comes to the pressure tank, higher pressure means less water for drawdown. Generally speaking, the air in the pressure tank should be set 2 PSI below the cut-in pressure.
  4. Drawdown of the tank
    The amount of water that will come out of the pressure tank before the pump turns on is known as the ‘drawdown’. As previously mentioned, short cycling of the motor produces heat, which has negative effects on the lifespan of the motor. For example, with a pump that pumps 5 gallons a minute, the drawdown on your tank should be around 5 gallons.

With all things considered, the size of your pressure tank directly correlates to the life expectancy of your pump. Taking the extra time to calculate the correct size will easily help prevent rapid and unnecessary pump motor cycling while also providing a constant pressure level in your home between pump cycles. Utilize the four determining factors from this post to find the ideal A.Y. McDonald DuraMAC™ pressure tank if you’re looking to lift some weight off of your pump’s shoulders.