When a water tank loses pressure, a basic knowledge of how the system operates will be helpful in trouble shooting the problem. There are several types currently on the market with one of the most popular being the bladder pressure tank.
What is a bladder pressure tank? It is a tank which uses pressurized air and water separated by a membrane (bladder). The manufacturer pre-charges the bladder at the factory. An average bladder pressure tank will last anywhere from 5 to 10 years.
How do bladder pressure tanks work? As water pressure changes, the volume of air in the bladder pressure tank contracts and expands. Periodically, the amount of air in the tank should be measured and the tank recharged if the air is too low. Bladder tanks do not provide any useful water storage capacity.
What functions do bladder pressure tanks serve?
- Maintain a desired range of water pressure in the distribution system.
- Minimize pump cycling, preventing frequent starts and stops protecting facilities from damage.
- Protect against water hammer.
Troubleshooting Guide:
- Disconnect electrical power to pump
- Drain the tank by opening the closest faucet
- Check tank pressure by placing a tire gauge on the air-charging valve on top of tank
- Add air if the pressure is more that 2 psi below the pump cut-in pressure (lowest pressure in the range). Use a tire pump or air compressor. Use caution with an air compressor.
- Release air if the pressure is 2 psi above the pump cut-in pressure
- check for leaks in the air charging systme. Use a soap solution to check the air charging valve for leaks.
- Re-start the pump and run through a normal cycle to verify the settings.
Helpful hint! If the tank pressure drops, the bladder may have a tear or hole in it.
Check for waterlogged bladder pressure tank problems
A tank is waterlogged if it is completely filled with water or has too much water to function correctly. Waterlogged bladder pressure tanks contribute to the following problems:
• The pump motor cycles – turns on and off – too often. Frequent cycling can shorten the lifespan of a
pump. 1 to 5 HP pump motors should not cycle more than five times an hour. If your pump is cycling,
check to see if the tank(s) is waterlogged.
• Unsatisfactory coliform samples or taste and odor complaints. Waterlogged tanks contain stagnant
water that can contribute to bacterial problems or taste and odor complaints.
• Premature tank failure. The inside walls of a waterlogged tank can corrode and
weaken from the exposure to water.
Helpful hint! It is often most cost-efficient to replace a waterlogged tank.
See these and other tank pressure data solutions at the Washington State Department of Health.
If your tank is waterlogged, check for possible causes: Bladder pressure tanks can become waterlogged for many reasons. Some of the more commons reasons are:
• Sediment, such as iron and manganese, can coat the surface of a bladder, causing it to harden and become less flexible.
• Sediments can plug the fill or draw line, preventing the tank from filling and emptying normally.
• High levels of chorine can damage the bladder, causing it to become brittle and less flexible.
• Tanks sitting directly on the ground rust and lose structural integrity.
• Chlorinators give off corrosive vapors that cause the tank to rust. Remember! When working with bladder pressure tanks it is important to read and follow the Manufacturer’s Safety Warnings!
For freeze protection contact HEAT AUTHORITY (866) 805-HEAT or visit them online @ www.HeatAuthority.com