Filter Vessels / Model 4-8 Indicating

These filters will let you know when your filter bag needs attention. This allows you to maximize the efficiency of your operations and reduce system downtime by changing filters only when they really need it. You’ll save time, money and effort, because you’ll use each bag to its maximum capacity, since change-out will be based on the remaining life of the bag, not on someone’s best guess.
Model 4-8 Indicating Specs & Dimensions.PDF | Filter Bag Specs for Series II Bag Housings

Features

• Low pressure drops
• Permanently piped housings are opened without disturbing the piping or requiring tools
• Covers are O-ring sealed
• Carbon or stainless (304 or 316) steel housings
• Housings are electropolished to resist adhesion of dirt and scale
• Large-area, heavy-duty baskets
• O-ring seals: Buna N, EPR, Viton® Fluoroelastomer, and Teflon® fluorocarbon resin
• Two pressure ratings-150 and 300 psi
• Indicating device is mechanical, no tubes or orifices to clog

New Features

• Integral Differential Pressure Indicator (non-clogging)
• Electric Micro Switch included - 3-wire or 4-wire
• Electric Switch has dual actuation (one for requires attention soon and one for requires immediate attention)
• Standard is one set point, optional is 2 set points
• Optional explosion-proof Pneumatic Switch
• Optional Digital Model available

Basket lip pushes down the indicator arm (A), which in turn mechanically actuates the visual readout arm (B).

As Amount Of Trapped Dirt Increases, Pressure Drop Increases, And The Remaining Life Of The Filter Decreases

That's right, as the pressure drop across your filter increases, additional dirt-holding capacity decreases. As the chart illustrates, at a 5 psi drop in pressure, over 90 percent of the filter's dirt-holding capacity has been reached. When the pressure drop has increased to 10 psid, it has reached 95 percent of its total dirt-holding capacity. For each additional 5 psi pressure drop, the amount of extra dirt retained decreases dramatically. As a matter of fact, pressure drops greater than 15 psi retain no appreciable amount of additional dirt. Our line of indicating filters automatically and intelligently sense these pressure differences, and will indicate when the optimum time to change the filter element in your system, saving you time, money and effort.

A Unique Operation
The Indicating Filter is a mechanical device, without tubes or orifices that clog the indicator. Unfiltered liquid enters the housing above the bag, supported in a spring-loaded basket, and flows through. Solids are contained inside the bag, and as it becomes loaded, greater pressure is required to force liquid through the bag. Due to this increase in differential pressure, the spring-loaded basket is forced downward, actuating the cam that drives the indicator pointer, displaying the changes on a simple red/green scale. Red represents unacceptable pressure differential, indicating that element change-out is required. These units are pre-calibrated to indicate element change-out at 15 psi pressure differential.

A digital option is also available, providing an easy-to-read LCD visual display. It also offers a signal for electronic communication. No matter which display you choose, you can be assured that you’ll change your filter bag, only when needed.