Sep 11, 2017 in Blog Articles

1. Restrainer basket length too short.
Restrainer basket should be a little shorter than filter bags installed in it. If the basket is longer, the bag will be suspended without proper support which could result in bag top and/or bottom being torn or ruptured.

2. Excessive force used to remove bag from basket.
Filter media can get trapped in basket strainer perforations due to liquid velocity and viscosity, making it difficult to take the bag out. Excessive force used to pull out the bag can result in tearing or rupturing. The recommended way of taking out used bag is first to twist the bag top gently to peel away any trapped media from the basket perforation prior to removal.

3. Excessive flow rate.
Bag housing specifications invariably give flow rates which are double that which a bag can safely handle. Ensure that the flow rate is at most half that recommended by the manufacturer of the housing.

4. Pump installed on the outlet side of the housing…pump should always be installed on the inlet side.

5 Pressure differential exceeded 1 kg/cm². ..filter bags must be replaced when the pressure differential reaches 1 kg/cm².

6. Incorrect bag installation.
Filter bag should be installed by either by extending his arm so that his hand can reach the bag bottom, and then insert the bag all the way to reach the basket bottom, or if a bag installer is available, use it to do the same. If the bag is not installed fully, it will be suspended above the basket bottom which and liquid inflow will act like a hammer to tear the top, and rupture the bottom.

7. Power failure.
When power fails, back flush force within the filter pipeline sucks filter bag upward and suspends it inside the basket. If the inlet valve is left fully open, when power comes back, incoming liquid will act like a hammer dashing into the suspended bag. Without basket support, bag top will be torn, bottom will rupture, and in some cases, the whole bag will collapse into the basket, causing a complete system failure.

By following the proper procedure by shutting the inlet valve once power has failed and then reopening slowly once power has been restored, the suspended bag is given an opportunity to reflate gently and regain basket support.